From Hölder Continuous Solutions of 3D Incompressible Navier-Stokes Equations to No-Finite Time Blowup on ()
1. Introduction
Turbulent flows are characterized by the non-linear cascades of energy and other inviscid invariants across a huge range of scales, from where they are injected to where they are dissipated. In the 3D viscous incompressible flow the kinetic energy is transferred from large scale eddies to small scale eddies, in particular, if you inject energy at a wavenumber
kinetic energy will be transferred to the wavenumbers k s.t.
. In 2D viscous incompressible flow the kinetic energy is transferred from small to large eddies; in particular, if you inject energy at wavenumber
, then your energy will be transferred both to the larger and smaller wavenumbers; this fact can be flagged as an inverse cascade. This double cascade is due to the presence of two inviscid quadratic invariants: energy and enstrophy. Experimental, numerical and theoretical works have shown that many turbulent configurations deviate from the ideal three and two dimensional homogeneous and isotropic cases characterized by the presence of a strictly direct and inverse energy cascade [1]. It can be assumed that the flow is confined in a periodic box of size L and that the external forcing is acting on a band with a limited range of scales centered around
. It is important to discuss the case when the horizontal size, L of the domain is finite and no drag force is present so that a condensate forms in a split cascade regime. With layers of fluid of finite height, there is a path that saturates the inverse cascade. In square boxes, the condensate takes the form of a vortex dipole. In [2], mild solutions to the Cauchy problem for the forced Navier Stokes equations have been sought by applying the Duhamel principle and developing the corresponding (to NS equation) integral equation. (
) with the heat semigroup:
where the bilinear form
. With external related force term: (
), where
is the Leray projector. See the
development in [2], where it shows clearly how it is defined in terms of the Fourier multiplier. Using Fourier transforms and introducing general tempered distributions living in a unique functional space, first a result on the existence of small solutions to the integral equation associated with Navier Stokes equations in this functional space setting is referred to and then in (Theorem 2.3 ([2] proven on page 17 shows that there is not an imposing of any smallness assumption neither on initial data nor external forces). There, it is concluded that there is a finite bound in norm of the expression:
for each
,
for all
. See [3] for asymptotic results using heat kernel associated with Heat equation. Considering the scaling
where
as defined in Section 2, Planchon [3] has shown that for scale invariance on a critical space that studying the asymptotic behaviour of the velocity of NS equation for large time t is equivalent to the study of large
with fixed time. It is shown there that as t approaches infinity that the natural space scale is
as in the Heat equation. Replacing x by
in the solution of the other velocity term involved in the scaling and letting t approach infinity, we obtain the same result as if we let
approach infinity in
(
approaching zero here). It is proposed that this limit should also be a solution of the N.S. equations. For two-dimensional problems, Hasan et al. [4] have introduced a new approach to solving 2D unsteady incompressible Navier-Stokes equations. Now on the topic of well-posedness of solutions to Navier Stokes equations, Wang et al. [5] have examined globally dynamical stabilizing effects of the geometry of the domain at which the flow locates and of the geometry structure of the solutions with the finite energy to the three-dimensional 3D incompressible Navier Stokes and Euler systems. The global well-posedness for large amplitude smooth solutions to the Cauchy problem for 3D incompressible NS and Euler equations based on a class of variant spherical coordinates has been obtained, where smooth initial data is not axi-symmetric with respect to any coordinate axis in Cartesian coordinate system. In the present paper, proposition B (hence A) is proposed to be true in the Millennium problem for the PNS Cauchy initial value system of equations. The blowup points for Hölder functions in higher derivatives can be shifted procedurally to arbitrarily large time t. However, at infinity it remains to show that there is no blowup there. Here the case of the asymptotic limit as
is proposed to exist [3]. So the claim is that there is no finite time blowup on
. Taking
establishes non smooth or singular solutions at a finite time. First it is singular solutions that we seek in
space and subsequently claim that there exists a sequence of such functions that can converge to a
function.
Several general inequalities are used to arrive at these claims. In particular the Hölder inequality is used and because of the compactness of the 3-Torus the inequality involving the
and
norms is used through the finite measure of the space. Also Jensen’s inequality is used in a few places as well as the Preköpa-Leindler and Gagliardo-Nirenberg Inequalities. The main idea is that bounds are established for each compact torus and then in a limiting approach as a sequence of compact tori volumes approach infinity the Preköpa-Leindler and Gagliardo-Nirenberg Inequalities can be used to calculate the tensor product term in the expression given as
in this paper. Leray’s criterion for Navier-Stokes singularity states that if a solution to the Navier-Stokes equations becomes singular at
, then it is necessary that the velocity norm
for
, grows unbounded in the manner
as
. Here
may depend on s [6].
The aim of the author of the present work is to use the fact that solutions of the Navier-Stokes equations that become singular must do so in an isotropic manner. It appears in recent works [7] [8] that the perfect candidate for this manner of singularity is the solution shown to depend on the Lambert W function as shown in those works and in the present work as well. Future work will confirm that when each of the 3 velocities
are set as
where
and
, then there exists an auxiliary PDE which gives a solution dependent on the W function as in this paper.
For the parameters of
, where
and
, where optimal constants C and C3 exist with eigenvalue
the existence of dipole-dipole interactions are proven to occur. These interactions are essentially collisions of evolving 4-vortices which are known in the literature to not be integrable [9]. Upon collision the dipoles can overlap. An integrable dipole-dipole collision corresponds to a configuration where two dipoles propagate along the same geometric axis in the form of a parallelogram. In this work for small times in the PNS flow evolution multi-dipoles are shown to result from the Navier Stokes equations that are arranged in a sequence of symmetric Riemann surface pancakes that do not overlap. The Riemann surface plots in this paper show the velocity
versus the real and imaginary parts of small and large data
respectively. Finite time blowup occurs in the first derivative and higher wrt to t at the center
and
. The arbitrariness of small and large data addresses the problem posed in [10]. Essentially there is a flip-flop of two possible values for
, either small
or
. For the dynamic viscosity
there exists a function
such that as C decreases t decreases and as C increases, t increases. An equality is set to unity that involves the velocity
and parameters
,
,
and
associated with the z component of velocity for
expressed in terms of the LambertW function. There is a deformation or non parallelization in the dipole space configuration along the imaginary axis
. Eventually there is an optimal time where two dipoles of size d are situated away from the origin by distance L1 and L2 respectively and orientated with respect to each other by an angle
around the origin [11]. As time increases a return to symmetry is obtained as
. Thus, symmetry breaking for the PNS equations is proven to exist and there is a strong correlation between the optimal time of finite time blowup and the maximal symmetry breaking time. Strong symmetry breaking is also mentioned in [12]. For a variational formulation of Rayleigh Plesset cavitation dynamics with reference to the incompressible Navier-Stokes equations see Moschandreou et al. [13]. Finally high infinite spatially antisymmetric oscillations occur at the origin for
and at
.
2. Equivalent Expression for Navier-Stokes Equation
The 3-D incompressible unsteady Navier-Stokes equations (NS) in Cartesian coordinates for the velocity
,
:
where
is constant density,
is dynamic viscosity,
are the body forces on the fluid. Expressing the components of the velocity vector and pressure to
,
, coordinates
and time t according to the following form utilizing the non-dimensional quantity
:
The continuity equation in Cartesian coordinates, is
Using the previous transformations from
to non-
variables, multiplying the first three components of NS equation by unit vectors
,
and
respectively and adding modified equations within the set given by the 3 parts of Navier Stokes equations (components 1, 2 and 3) give the following equations for the resulting composite vector
,
Multiplying the previous equation by
and by
and the
component of the Navier Stokes equations(in
variables) by
and by
, (using transformations in
), the addition of the resulting equations recalling the product rule and finally setting the forcing to be equal to
, (also equal to pressure gradient force if
) I obtain:
Note that here the forcing term
does not counterbalance the non zero pressure gradient which causes flow to occur. It is equal to it, hence for negative (
), setting
, and equating the two
expressions then
. This is the conditional equation that needs to be satisfied as well as the PDE’s associated with the problem. It turns out as the paper shows that this equation is fulfilled as each term in it is zero for the final solution in
(similar equations in
and
follow.) The reason as will become apparent is that for a sequence converging to the z solution
will ultimately be shown for all real t and z,
thereby showing by Newton’s second law that
. Also for pressure function
defined as a Hölder continuous function in z, a sequence converges to the solution for P that is in the form of
for all real t and z,
. Hence the pressure gradient in z,
. Finally the relationship between
and
is:
The nonlinear inertial term when added to
and factoring out
gives:
. Multiplying the previous PDE in (a and b) by
and adding to it
gives a new PDE (call it (I*)) which has been solved in reference ([14]: Equation (6) there). This extra term when integrating the resultant PDE and using Ostrogradsky’s theorem(divergence theorem) has a zero contribution since
. (Recall: velocity is the radius multiplied by angular velocity. It is shown in this paper that the
norm of this term approaches zero.)
It is stressed here that the same analysis is possible where we can rearrange the terms in such a way as to add the first and third equations and get a PDE with
and
. So there will be three PDE in these forms and they are all coupled. This is identical to solving the original NS equations where the forcing terms are not counterbalancing the pressure gradient terms.
Taking the geometric or dot product of the PDE (I*) defined above with respect to
, it can be shown that a scalar and vector field PDE is produced. (See Reference [14] on page 388 to page 389 there.)
It has also been shown there that there exists a non linear operator
as shown in this paper which can be expressed in the form given in reference [14] on page 389 by Equation (19) there.(note that there in Equation (17) the left side of 3D (generalized from 2D to 3D in this section) Navier Stokes equation is set to zero which simplifies to the tensor product term. The analysis continues from Equation (19) in the present work. (see Equations (6)-(10) in Section (4))
3. Main Theorem for the Existence of Finite Energy Solutions
The following theorem as proven in [2] is the foundational theorem for the existence of finite energy solutions in the space
for each
and all
. Mild solutions to the Cauchy problem for the forced Navier Stokes equations has been sought for by applying the Duhamel principle and developing the corresponding (to problem (2) in Section 4) integral equation.
(
) with the heat semigroup:
where the bilinear form
. With external related force term: (
), where
is the Leray projector. The Leray projector is defined as the Fourier multiplier with the matrix component
satisfying
for all
and all
. The tensor product for two vector fields
is the
matrix whose
entry is
. The Fourier transform of an integrable function is
The following functional spaces are used in the theorem in the space of tempered distributions (
),
where
. For time dependent tempered distributions the following functional space also used is defined as,
A number a is called an essential upper bound of f if the measurable set
is a set of
-measure zero. That is, if
for
-almost all x in a space X. Let
be the set of essential upper bounds. Then the essential supremum is defined as:
if
and
otherwise.
Theorem 1 Every mild solution
of problem (2) in Section 4 corresponding to a singular initial condition and singular external force
satisfies
for each
and all
. Moreover, for every
there exists a constant
such that,
(1)
This is a top down existence result and subsequently in the following sections, the form of the existing solution in a bottom up approach are provided where a sequence in
for each
is shown to converge to a
solution as required in the proof of the Millennium prize problem proposition B) for the Navier Stokes equations. The main results to follow aim to present the case of global existence of solutions for all
. The novelty of the present work compared to other approaches is that the Navier-Stokes equations are solved by a direct approach whereas in other works in the literature a purely functional analytic approach is usually sought for, however up to now the latter way has proven to be limited in establishing definitive results in global regularity.
4. Governing Equations and Main Results
Consider the incompressible 3D Navier-Stokes equations defined on the 3-Torus
. The PNS system is,
(2)
where
is velocity,
is pressure and
is the forcing function. Here
, where
,
, and
denote respectively the x, y and z components of velocity. Introducing Poisson’s equation (see [13] [14] and [15]), the second derivative
is set equal to the second derivative obtained in the
expression further below, as part of
, and
(3)
where the last three terms on rhs of Equation (3) can be shown to be equal to
. Along with equations below, the continuity equation in Cartesian co-ordinates is
. Now for
,
(4)
Next the right hand side of the group of transformations Equation (4) are mapped to
variable terms. Here
is unity,
(5)
The double transformation here is used for notational clarity. For a deeper connection see [16] where two scalings can be used for the Euler equations and the ratio there shows a hidden scale symmetry. Note that the form of the rescaled velocities is related to the definition of the LambertW function W, such that
, where
depends on t and proportional to
approaching zero for infinite time t. It is true that the ratio
is equal to 1 and not zero or infinity so that it is well defined making u finite in the limit. Note that the original Navier-Stokes equations are preserved and rearranged in the following form,
(6)
(7)
(8)
(9)
(10)
where
are given in [7] and [8] and it has been shown there that this decomposition is valid and that on a volume of an arbitrarily small sphere embedded in each cell of the lattice centered at the central point of each cell of the 3-torus,
is negligible for the case of no viscosity (Euler equation) and for viscosity
the existence of a dipole occurs with the centre of the dipole occurring shifted away from the centre of the given cell. From this equation we can solve for
algebraically and differentiating wrt to
and using Poisson’s
equation by setting the representation of each of the two partial derivatives wrt to
equal to each other, we can obtain,
(11)
(12)
where each
is given as,
(13)
where
is the external forcing vector and
is the velocity in each cell of the 3-Torus.
The singular forcing is expressed in terms of WeierstrassP (P) and LambertW (W) functions in
directions and defined as,
for a full 3D dimensional plus time general function
. When
the forcing is singular at
. An r-ball exists about any point in
where
. Here
where
is the center of a given r-ball. The idea is that we can choose an arbitrary ball in
. We set
. At the center of ball forcing is singular as
. Forcing will be arbitrarily large in an r-ball for
with
. Considering circumscribed cubes each containing an r-ball. The union of cubes is the 3-Torus since it is compact. The dimension of the cubes is such that by periodicity the forcing is singular at the centres of the cubes.
5. A System of Singular PDE for the PNS Equations Due to Initial Conditions and Forcing
The following system of PNS initial value problems is considered with singular forcing as given above,
(14)
where
is the nonlinear partial differential operator defined by Equations (11)-(12) and Equation (13). The different uncoupled IVPs starting with
and indexed by n are solved. Each IVP will produce solutions such that the initial conditions are not smooth due to non-smooth forcing. The idea is to solve these IVPs for each n and see if Hölder continuous functions exist for each n. The Ψ are related to the form of the solution for
and will be shown to exist and one can see how the n compositions of Ψ affect the solution once the
PDE is solved. The question that arises is, what happens when n approaches infinity? Can we use a problem with singularities to obtain in the limit a globally smooth problem? It has been proven that for initial conditions and singular forcing existing in a unique space of tempered distributions that a finite energy solution exists in
for all
[2]. So then in a top down approach one can take a sequence in
converging to a
function of the above initial value problems. However one does not know what the form of the functions are here. So a bottom up approach must be adhered to solve the PNS system. Next continuing with the solution procedure consider the
as the center of each cell of the lattice in
, upon substituting the WeierstrassP functions and their reciprocals into Equations. (11)-(12) together with the forcing terms given by Λ (in Equation (13)), it has been determined that a major simplification of Equations. (11)-(12) occurs. The torus
is considered which contains a union of the
balls. Here
throughout the lattice for all cells or boxes
in it with side lengths of
. In [17] solutions of the Navier Stokes equations are posed on large periodic domains
and on the whole space
. One would expect, when the initial velocity is sufficiently localized that the solutions on a large enough domain should mimic those in
. In this paper, we primarily focus on each cell
of the Torus. For functions
there exists a compact set about zero, i.e.
where the forcing functions have mean zero and on a suitable subspace the solutions u of the PNS equations also are mean zero functions. (at least in one direction
) The purpose of the m parameter in the P function is to vary it according to decreasing arbitrarily small amounts so that
for arbitrarily large
. The form of the full Navier Stokes equations is expressed as a perturbation equation valid in an arbitrary
ball of
. This is precisely
, where U and V are differential operators making up the full 3D Navier Stokes equations. Two PDEs are being considered here. The first one is listed as in Equations. (11)-(13). For this one the solution in [7] is proven to be
locally Hölder continuous with
and the second one here is V,
For this second part
. There are two situations that may occur here. First the asymptotic limit as
gives
. Secondly, in Section 9 due to the Laplacian, an expression named
which is infinite at
allows us to divide by M so that it can be shown that V is not infinite. The solutions of
as the first order perturbation,
due to isotropic blowup [18] are in the form of a Hölder continuous function with parameter
. Equations (11)-(13) are solved first and then
is substituted into the later equation to obtain the condition of arbitrarily large data on a suitable subspace to be described. The idea here is to use the LambertW (or Ψ function) dependent solution obtained in the first step and substitute it into the second step equation. The arbitrary large data is in the form
where
. The
component in the PNS system is set as
where C is a constant. When this solution is substituted in, algebraically we can solve for
where S is a function associated with the
equation. If
then the function
is increasing in s as s gets arbitrary large. It turns out that
is in general linear in s. Here
progressively approaches
.
Calculating the tensor product term in Equation (9) see [14] and using Equation (21) in [14] shows its volume integral to approach zero due to
approaching zero where the Hölder, Preköpa-Leindler and Gagliardo-Nirenberg Inequalities have been used. Also
where
. In Equation (6) of [14], for the vector
,
. Furthermore in Equation (10) [14] there the term
is the divergence of the vector
. Using Ostrogradsky’s formula in terms of the vorticity
and velocity
, . Now for a specific pressure P on an R-sphere, , where
assumed to
be bounded and contain the pressure terms in Equation (9). The sphere is
. Since the 3-Torus is compact there are m closed sets covering it. The outer measure is used where the infimum is taken over all finite subcollections
of closed balls
covering a specific subspace of
. The specific subspace
is within
measure of the 3-Torus and is obtained by minimally smoothening the vertices of
and slightly puffing out its facets. Also inner measure is used where the supremum is taken over all finite subcollections
of closed balls
inside
. Generally by Hölder’s inequality,
is shown to be positive for pressure defined to be in
. (The pressure will turn out to be unbounded from below as t approaches infinity). Furthermore, u will be shown to have derivatives that blow up in finite time on a specific subspace of the solution space. The following string of inequalities occurs bounding the PNS operator equation on the interval
where
is proposed to be the first blowup of PNS equations:
(15)
(16)
(17)
(18)
(19)
(20)
In the above inequalities the integration is defined on any finite volume Ω contained in the larger volume
. From this it can be concluded that
as the volume tends to that of
. The term
where
and for arbitrarily small
,
. Note
that at a potential first blowup at
,
. In Inequalities (18) and (19), Jensen’s inequality for concave functions has been used. Note that the sup norm of
does not occur at the origin but occurs further away in each cell. For
the sup norm is bounded by the
norm where the integral is in the Lebesgue sense. The above sequence of inequalities applies to mean zero solutions and in particular Inequality (18) on the space
(see Section 8). On the space
we can calculate the antiderivatives of each of
,
and
wrt to x, y and z respectively, as given below,
and
Also by [19] the following inequality results for Inequality (18),
6. Inequalities for Derivatives
By the Gagliardo-Nirenberg inequality, in the class
of functions f under consideration the following is true,
with
for
. Also
,
and
. There it is obtained that,
, with
,
, and
for
.
Here the case of
is considered for Inequality (18) for the infinity norm of the gradient of b. It is evident upon calculation that,
and
In Rumer and Fet’s exposition [20], (See also [7]) where the Laplacian is defined as an integral over an
ball with centre x,
and Jensen’s inequality is used (with
in the general form of the inequality), the following is determined,
where
is the differential of
at x and
. This is a 3 × 3 matrix. As
,
in the ball of radius
and due to periodicity the integral on
becomes zero and subsequently the integral is zero. In the sequence of inequalities ending with Inequalities (19)-(20) (
there), the measure of excess sets
approach zero as n gets large(infimum is taken of integrals over all coverings of 3-Torus)
is vorticity
multiplied with
and to begin with
is the inverse of the divergence operator integrated over an arbitrary cell of the 3-Torus lattice. Here the identity
was used. This will be validated further in this work. The chain of inequalities above imply that, in general
since the two vectors
and
can be in the same direction.
Note that the Hölder, Preköpa-Leindler and Gagliardo-Nirenberg Inequalities have been used for the tensor product term in Equation (8) which is negligible. For locally Hölder continuous solution given by Lambert W based solution to be developed further, the tensor product term
is independent of s and for large
can be omitted. Also in view of the following inequalities there will be a blowup for large infinite volume
. In other words we consider increasing finite volumes of 3 Tori,
In the above inequalities the integration is over the volume
. As the volume increases towards infinity (integration over
) and we divide by it throughout the inequality then,
. In the expression
in Equation (9) the following is true using Hölder’s inequality associated with the product of three terms in the tensor product term,
Theorem 2 Let
with
. Then for every function
,
, and
,
.
It is known by divergence theorem applied to a vector field
, where
and
, that,
, then,
Furthermore, by multiplying by negative one throughout,
where the volume of the ball approaches infinity. Also, the pressure term
and its spatial derivatives are assumed singular.
7. Log Convexity of
Norms
The following theorem is required to apply to Inequality (15) in order to give an upper bound for the higher order norms appearing there.
Theorem 3 Let
and
. Then
for all
and furthermore we have,
for all
where the exponent
is defined by
In Inequality (Equation (15)), by Log convexity theorem,
and
Similarly,
8. Subspaces of Solutions to the Navier Stokes Equations
In the way of an illustration on how to obtain solutions to 3D Navier Stokes equations, consider the following space
defined as,
(21)
where R is a sufficiently large positive number.
It can be calculated that on this subspace of solutions to PNS equations, the following part of Equations. (11)-(12) is identically zero,
(22)
There is an index
which is the center of either a cell (or cube) of the lattice
or the center of a viscous dipole. Also in Equations. (11)-(12) are the forcing terms
which vanish as a sum in the
expression leaving us with the forcing term
and is singular by definition.
Analogously we have the other two spaces for the 3D Navier Stokes equations,
(23)
(24)
These two spaces are obtained by applying Geometric Calculus method and theorem in [14] respectively to Equations (1) and (3) and Equations (2) and (3) of the Navier Stokes equations, respectively. (PNS equations are written in rows as
Finally we look for a candidate solution on the Cartesian product space:
(25)
Now
is non empty and defines the Cartesian product of three closed segments on each of the x, y and z axes. The candidate will prove to be a solution that is a function of the LambertW function, W as a function of a linear combination of the variables x, y, z and t. Here, we can build the 3-Torus from each of the restricted subspaces defined above. For arbitrarily large data
the linear independence of each of the three spaces is used to eliminate constants in the linear independent formulation leaving us with the W solution as a function of
and t only. Applying the Cartesian product provides us with a 3D volume 3-Torus and further, we will see what the time derivatives look like for both pressure and velocity. If there is a blowup, then in [18] the isotropic nature of blowup is guaranteed. This nature of a possible blowup is proposed here too since the W function solution will be a linear combination of
and t in the intersection space. (Variables in
are carried over through the
transformation.)
9. The Reduction of PNS to LambertW Based Solution
Recalling the full PNS PDE from Section (3):
where L is given in Equation (10) and the
are given after Equation (11). Here the sum is not multiplied by a small term
since the product of the reciprocal P functions cancel out in the expression for L (retaining the PDE where no P functions occur for the zeroth order perturbation equation). On the subspaces given by Equations (21) (23)-(24), the full PNS equations reduce for example (on
) (see Equation (22) and its related equations using geometric calculus) to:
(26)
where the two Laplacian expressions have been expressed in terms of the difference of the average of the velocity
in the epsilon ball and
evaluated at the centre of the ball. Here the centre x of an arbitrary ball is such that
. The ball is an arbitrarily chosen one as a subset of the 3-Torus. Of course the uncountable union of all such balls is all of
. See [20] and [7], where the reduced PDE was used to prove finite time singularities. Also symmetry breaking is proposed to occur. The expression
and is shown in [7] [20]. Here there is a singularity in
as
. (Note that division by
,
and if
is Hölder, then
as one approaches the first derivative blowup point at some
). The idea here is to compare and equate the infinitely large expression
with an arbitrarily small
part of the center of a given ball for the
PDE. Using Geometric algebra it is possible to obtain two similar PDEs but one in
and the other in
. Using the definition of the spaces
for
, and using the definitions of
, for
,
for
and
for
where
are centres of the arbitrary balls in
for
where N is a Net to account for uncountable number of balls, use the chain rule to express the part of reduced PDE given as,
(27)
whereby it becomes equivalently on the spaces defined (using chain rule where
) as:
(28)
Here the same idea is applied to all three PDEs obtained for
,
and
on their respective subspaces. Recall that there exists an extension through the Cartesian product which extends the solution to all of
. The shifts in
and
are necessary in order to obtain and integrate the final reduced PDE over
and set it to zero and to generalize to any ball as a subset of
as a function
of the centres. Letting
for example be order
so that their
product is unity and similarly letting
be order
for nonzero
with no restriction on the size of
then their division will be order unity too. Using the Kolmogorov length and velocity scales where the Reynold’s number
where the length scale
it is observed that the velocity is proportional to the viscosity and the proportionality constant is
. Here the function
is taken to be order
for all s in a time s-ball
centered at possible yet to be determined blowup points
. It turns out that the reduced PDE in Equation (26) has solutions that are locally Hölder continuous with the exponent 1/3. This is in terms of the LambertW based solution given in Equation (37)-(38) and the expression
divides by
and in the limit as
approaches zero. It is noteworthy to check that the LambertW based solution satisfies this limit and it was seen that this is the case. Also the expression
divided by
in the limit is zero. Here the reduced PDE becomes,
(29)
where
is order 1 as the limit is taken as
and
leaving us with the result order 1 on the RHS of PDE Equation (28). Note that
and this has been used to obtain Equation (29). Finally, an integration about all
is performed to recapture the general spatial and time components of Equation (29).
Expressing
, where
is a cube containing a circumscribed sphere of radius
. The 3-Torus is partitioned in such disjoint cubes or cells. Writing the PDE in Equation (29) as,
with the associated nonlinear differential operator L. Here
is taken to be continuous and it is written that,
and
and in the limit as the radius of the ball approaches zero applying to both sides of equation gives,
Here if the argument of the summation is not zero then due to uncountable summations a contradiction follows, thus,
for any
.
See Appendix 2 for the generalization of the solution to Eq. (29) and the creation of a sequence of points that are not contractive or Cauchy and shift the blowup points in time to +infinity.
10. Mathematics Preliminaries
Let
be a measurable function. For any
, we define the
norm
Furthermore, we define the
norm of f as
with Lebesgue measure m.
Proposition 4 If
is measurable, then
almost everywhere on E. Also, if
is a closed interval and
, then
is the usual sup norm on bounded continuous functions.
Theorem 5 (Holder’s inequality for Lp spaces) If
and
, and
are measurable functions, then
If
, a function
is said to satisfy a Hölder condition of order
(or to be Hölder continuous of order
) if
(30)
Denote by
this set of functions. It can be shown that
(31)
is a norm which makes
into a Banach space. Also
and that the inclusion map is continuous with respect to the norms defined above (i.e., the norm on
previously defined ) and that on
also defined.
11. Fluid Systems: Estimates for Reduction along 3 Principal Directions
where
. Under the flow system for Euler equation in previous flow chart,
(32)
(33)
Also for PNS system,
(34)
(35)
where in the flow system u for Navier Stokes equations the LambertW solution as a function of W is decreasing after the first blowup on
. For constant finite bounds of
and
see theorem 2 Section 2 under the heading “Inequalities on the torus
” [21]. There if one of indices p or l is chosen to be equal to 1 there is a bound of the
norm of the gradient of u or
using the Preköpa-Leindler and Gagliardo-Nirenberg Inequalities as proposed in this paper.
Under the Euler flow system the following integral is written and Jensen’s inequality is used,
12. Results
The singularity of the solution in terms of the LambertW function occurs at the point
where the W function has a first derivative singularity.
Interaction of two unequal monopolar vortices of opposite signs is shown in Figure 1. Advection can occur for the weaker vortex by the larger vortex. Two monopole vortices of opposite vorticities close to one another, form a dipole vortex that moves together in the direction of the flow between the two vortices. For example, for a positive vorticity vortex on the left side, which has a counter
Figure 1. Interaction of two unequal monopolar vortices of opposite signs. A stronger positive vorticity vortex on the left, results in a counter-clockwise rotation as it drags the weaker vortex along its streamlines.
clockwise flow and a negative vorticity vortex on the right, which has a clockwise flow. The counter-clockwise flow of the left vortex advects the right vortex upwards, while the clockwise flow of the right vortex advects the left vortex upwards.
The solution in [7] occurs for large
as a function of time t. The solution was rescaled in
. (In the form
, where
is a large complex valued shift.) In [7] this was valid for
that is the Euler equations. In this paper the same shift occurs but as
approaches that of
, where
and
, and given the reduced PNS equations the relationship in terms of the definition of the LambertW function as shown in Equations (37)-(38) exists. The variable
is complexified. As a result the first derivative wrt to
can be written using the chain rule as,
(36)
Here it is assumed that
, where
is arbitrary large complex valued data in the complex norm in the complex space
. (The test value of the form of this function turns out to be
, where B is precisely determined to produce the Riemann surface further obtained and
,
where central point occurs for
and
is the dipole off center point for high viscosity. There are two
balls, one about the origin with associated low viscosity and one about the shifted away from origin dipole center associated with high viscosity). Also the variable
is the complexification of the
-component of velocity given by PNS equations on
. (recall one can use either
or
or
or
with a factor of
introduced. It can be shown that as
gets large
. Also note
for the viscous case)
The solution of the Navier Stokes equations has been determined to be exactly,
(37)
(38)
where W is the LambertW function. Setting
and differentiating wrt to y and set
from Equation (24) in
space. So one can confirm that this expression approaches zero as
. The idea is to use all 3 subspaces to conclude that continuity equation holds and is satisfied. (Not shown but can be derived similarly that
and
where one seeks solutions for
and
. The initial condition for large data
is set to
,
and x, y and z are set respectively equal to either
,
or
. Then in the general solution there is an unknown constant
which can be determined and substituted back in the solution leading to Equation (37)-(38) for example. The other two cases can be dealt with similarly and give similar forms. The derivatives vanish at
,
and
respectively. Also in each space two of the three constants in
are always zero. We do however use all three spaces concurrently in light of using the Cartesian product to get all of
and in the limit all of
.
Substituting the shift in
for
gives the following,
(39)
(40)
The argument of the shifted Riemann surface obtained is derived from the definition of the LambertW function. The argument of the W function which is a function of
, say
is set equal to
. The “plot3d” command is used where four functions are plotted together, that is,
,
, u and v, where
. Here w is the complex LambertW function associated with the viscous solution. One solves for
in terms of
.
The command lines in Maple are:
Table 1. Table to calculate the Riemann surface associated with
in the following Maple algorithm.
adjustment C |
|
|
|
0.5 |
0.05 |
−0.052 |
100 |
0.85 |
0.05 |
−0.052 |
100 |
0.95 |
0.05 |
−0.052 |
100 |
0.35 |
0.05 |
−0.052 |
100 |
0.85 |
0.05 |
−0.052 |
100 |
0.25 |
0.05 |
−0.052 |
100 |
0.85 |
0.05 |
−0.052 |
100 |
0.85 |
0.05 |
−0.052 |
100 |
0.85 |
0.05 |
−0.052 |
100 |
Table 1 is used to calculate the Riemann surface associated with
in previous algorithm.
The value of C in Table 1 is determined from the following condition,
(41)
Also
is set to either unity or
for the density of water in the results obtained in this section. The plots given use
however increasing
to 1000 can give similar results once
is decreased by 3 decimal places.
When multiplying the left side of Equation (41) by a constant C it can be easily determined that the new left side will be either less than zero or greater than or equal to zero. So C varies such that
. This corresponds to a change in
where
. The end result is that the time is also varied according to this value of C hence
. With these values variations in Riemann surfaces occur resulting in the change in symmetry breaking outlined in this paper.
13. Proof of an Optimal C Constant
In this section an optimal constant C is proven to exist where the greatest symmetry breaking occurs amongst the data shown. See Figure 2 where the Riemann surface is shown for the constant
. Here there is the greatest deflection where the angle is close to 90 degrees between dipole pairs. The four vortex system
Figure 2. Non-integrable Dipole-Dipole interaction, with greatest deformation in y direction. Greatest non-symmetry associated with greatest time evolution in flow.
is in general a non-integrable system, hence analytical methods cannot be applied. See Figure 3, Figure 4 for the case of a 4-vortex integrable system, with symmetry re-emerging as time gets large. The plots in Figures 5-8 are of the integral of
wrt to w on the window range [−2.5, 2.5] for example. This integral must be calculated using substitution:
, calculating the differential
and back substituting to do the integral in w. The following expression was obtained,
The general non-integrable equally-sized, equal circulation dipole-dipole setup is displayed in Figure 9. Two dipoles of size d are situated away from the origin by distance
and
respectively and orientated with respect to each other by an angle
around the origin. The general initial configuration is given by the angle
and the lengths
. In the limit of
, the ratio
is defined, as the limit is taken. See [11] for detailed analyses of the configurations used in Figures 9-11 and subsequently compare to the analysis used in this paper associated with Figure 12 through 13. When the vorticity in a given region from one solution is negligible or constant, we can add another solution with local nonzero vorticity in that region, and one has
Figure 3. 4-vortex integrable system: Symmetry re-emerges for time approaching infinity.
Figure 4. Top view of re-emerging symmetry 4-vortex integrable system in previous figure.
Figure 5. Extremely small value of C for the plot of w vs
.
Figure 6. Larger value of C for the plot of w vs
.
Figure 7. Optimal value of C for the plot of w vs
.
Figure 8. Next larger value of C for the plot of w vs
.
Figure 9. Setup of the non-integrable four-vortex dipole-dipole collision defined by two parameters, the ratio of the dipole separations from the origin
, and the angle of incidence
. The four vortices are arranged such that two dipoles of size d with both orientated such that their trajectories intersect at the origin (see [11]).
Figure 10. A dipole-vortex interaction.
Figure 11. Initial setup of the integrable four vortex interaction, with the initial dipole separations defined as d, and impact parameter between dipole midpoints represented as
, and horizontal separation between dipoles L.
zero vorticity outside of it (e.g. a dipole vortex), and the effect of one on the other will be simple advection. This means that more general solutions can be constructed as a patchwork of different nonlinear solutions as long as there is no overlap of vorticities such as in Figure 12 and Figure 13. This is a sporadic turbulence state. Each solution, be it a dipole vortex, a monopole vortex or a chain of vortices, or a sheared flow, can coexist and interact only weakly through occasional collisions. However when there is overlap (see intersecting or overlapping dipoles in Figure 2, Figures 14-16), as in the case of a dipole vortex plunging into a shear layer, if the shear is strong enough with respect to the dipole the large scale flow would likely shear apart the smaller structure, leading to a new,
Figure 12. Multi-vortex interaction, with uniform dipole separations. Highest symmetry case corresponding to small time evolution in flow.
Figure 13. Multi-vortex interaction, with slight deformation in y direction. Slightly symmetric case corresponding to slightly larger time evolution in flow.
Figure 14. Multi-vortex interaction, with some deformation in y direction. Increasing non-symmetry associated with larger time evolution in flow.
Figure 15. Multi-vortex interaction, with significant emergence of deformation in y direction. Non-symmetry is associated with this time evolution in flow.
Figure 16. Multi-vortex interaction, with second greatest deformation in y direction. Second greatest non-symmetry associated with second greatest time evolution in flow.
probably a slightly different large scale solution with additional incoherent fluctuations that result from the breaking up of the small scale eddy. When the incoming dipole is large enough, the large scale periodic solutions can be disturbed enough that they become unstable and transform the nature of the flow. It is noteworthy to consider Figures 17-23 where iterations of solutions are applied to the initial solution given in Figure 17 given by the form of solution in Equation (37)-(40). It becomes evident that compositions of n W functions results in a shift towards
. Any finite number of compositions will result in a solution as well to Equations (37)-(40). In the limit, the velocity approaches a constant for all t. It is important to realize that proposition B of the millennium problem for the Navier Stokes equations involves proving that the forcing is zero which it will be when one differentiates the constant velocity wrt to t and using Newton’s second law. Of course the constant solution is periodic for all x and t. This situation exists since data was assumed to be given by
alone and arbitrarily large. One can
Figure 17. Plot of 1 iteration of W function solution:
.
Figure 18. Plot of 2 iterations of W function solution:
.
Figure 19. Plot of 3 iterations of W function solution:
.
Figure 20. Plot of 4 iterations of W function solution:
.
Figure 21. Plot of 6 iterations of W function solution:
.
Figure 22. Plot of 19 iterations of W function solution:
.
Figure 23. Infinite limit of n compositions of solution approaches a constant for initial arbitrarily large data
.
superimpose a more general periodic solution about the constant
solution and fulfill the requirements for the millennium problem. Note that in Equation (29) solutions are also of the form
,
and
. These functions can be taken to be periodic on
. Superimposing is possible since
is a constant in the limit as
.
14. More on the LambertW Function Solution
Note that we use the following: Given a constant c we can solve
simply by solving
which says
, W is the LambertW function. The values are large in
for viscous flows but become physical when we divide by large numbers. The quantities are scaled down by dividing u by an appropriate large quantity.
The vanishing of the derivative of
wrt to
is connected to Rummer and Fet’s theory [20] of expressing the volume integral of the Laplacian on an epsilon ball, where in Equation (42) the following reduced PDE occurs when viscosity is included in the PNS equations and thus the reduced form obtained,
(42)
See Figure 24 for a general dipole configuration. The viscosity term is not taken to be zero but the gradient of omitted term in the derivative of
wrt to
vanishes itself. This is due to the chain rule and the large shift in the initial condition in
. As a result dividing by viscosity
, the following equation is introduced,
(43)
Figure 24. A Dipole pair associated with a contour plot of
-component velocity
.
(44)
eigenvalue Now it has been pointed out in chapter 8 of reference [7] and [8] that since
approaching 1 from the right of 1 provides us with a blowup at plus infinity from the right side of some
with linear graphs intersecting arbitrarily large
values at
, that it remains to show that the simplified equation, Equation (42), with
introduced in place of the derivative term squared has a solution which is Hölder continuous and whose solution has a first derivative blowup from the left at blowup point
. This has already been shown in [7]. Taking
, we have full viscosity in the PNS problem as expected. In [7] the solution was in terms of a LambertW function and for zero viscosity. Here it is seen that as
goes from 0 to maximum viscosity that the solution
has a derivative in
which approaches zero.
15. Calculation of the Pressure Term P Using Integration by Parts
In this section the pressure is derived from the previous section’s calculation using Jensen’s inequality and integration by parts. In the sequence of inequalities and in particular for the last one,
where
. It has been shown in [7] that the solution of PNS is locally Hölder continuous with exponent
for Euler’s equation. So then g must be the pressure gradient term (in terms of reciprocal of P functions multiplied with this Hölder continuous function). By integration by parts it can be written that,
(45)
In the previous integral expression
is solved for by differentiating both sides wrt to t with solution given as,
(46)
Next the solution for
is set equal to the fractional form
from which we solve an integral equation for
. Here we differentiate both sides wrt t and solve for
. Symbolic algebra is used here. The following is verified to be,
(47)
After back substituting
in expression for g the pressure is verified to be obtained as the following,
(48)
Finally to determine the constant m in the WeierstrassP (P) function the expression which is dependent on m and z (spatial parts of spatial derivative of pressure function) this is set equal to −π a transcendental number. Here the scaling is for
and it can be seen that if
where
then the pressure in previous equation will always be decreasing.
(49)
and solving for the pressure P gives a Hölder continuous form plotted in Fig.26 given by the data in Equation (49). According to the result in [22] if the solution of the Navier Stokes equations is not smooth then the pressure will not be bounded from below. Figure 25 illustrates this as can be seen that the pressure approaches minus infinity as
. Here there is an inflection point in pressure at the point where the velocity derivatives are not smooth. Also we note that for Euler fluid dynamic system, the integrated infinity norm of
divides
inorder to obtain a constant and implies that . Interchanging the divergence and integral sign we have that which implies that . Here we note that for
and
norms the inequality is not always ordered such that the
norm is less than or equal to the
norm.
Lebesgue space of integrable functions This can be true
(a)
(b)
Figure 25. If the negative part of the pressure is controlled then the solution for velocity is smooth.
however if we consider an
ball about the centre of each cell of
or if we ensure that the function that is integrated in each normed space is such that the function
. See Figure 26. This will however be the confinement interval achieved through the scaling
. We recall that
. If we set
then we will have the norm of
space greater than or equal to norm of
space for u velocity field. Note that for the solution u given by the LambertW function W, the limit as
,
, where
through scaling. Next using vector identity,
(50)
For the Euler equation the theorem in [23] is used in the following which states that in the limit of zero viscosity there exists a non zero bound on the bulk rate of energy dissipation in body-force driven turbulence. There flows are considered in three dimensions in the absence of boundaries and a rigorous a priori estimate for the time averaged energy dissipation rate per unit mass,
is proved. We restate the theorem given in [23].
Theorem 6 Suppose
with periodic boundary conditions and
is a divergence-free vector field with mean zero and
has norm 1 in
. Let
for some integer
and
with periodic boundary conditions, and
be a mean-zero solution of the Navier-Stokes equations with body force
given by
Then the time-averaged energy dissipation rate per unit mass,
Figure 26.
norm compared to
norm.
(51)
satisfies
(52)
where the space-time averaged root-mean-square velocity U is defined by
(53)
and the coefficients
and
uniform in the parameters
and
are
(54)
(55)
For large Grashof number
a lower bound exists in the form,
(56)
where
is the Taylor microscale in the flow and the coefficient
depends only on the shape of the body force. The interpretation made is that the upper and lower bounds on
are in terms of the conventional scaling theory of turbulence where they are observed to be saturated.
From Equation (50) upon multiplication by
and integration over F results in,
(57)
where,
where the trace in Equation (57) involves terms as
and
for
.
(58)
In the space of
of the solutions to the Navier Stokes equations as seen in [7]
(59)
(60)
(61)
In [14] only
space is defined. As mentioned previously the other two spaces are obtained by applying geometric algebra method respectively to Equations (1) and (3) and Equations (2) and (3) of the Navier Stokes equations respectively. Next calculating using the chain rule in the previous spaces,
(62)
(63)
(64)
Next,
(65)
(66)
(67)
(68)
(69)
(70)
Substituting these expressions into
and taking the supremum norm,
(71)
consists of spatial terms that become infinity on the lattice of
and in particular on cells contained within each which contains the origin zero. In Euler’s equation this will be denoted by
where
is the kinematic viscosity and is approaching zero. As a result in the infinite limit as
and
,
is a non zero positive constant since spatial fractions as part of the infinity norm of
cancel with
as
approaches zero and K is less than or equal to arbitrarily small
. Here we necessarily have by sequence of inequalities that
where
is a scalar function. In calculating the solutions for
,
and
these are bounded by order
and this can be confirmed by substituting the solutions in terms of the LambertW function obtained in [7]. The reciprocal of the function in
must be shown in the paper to be absorbed by the pressure gradient term which is of fractional order
rendering the pressure term to not be
and thus the pair
. We note finally that the matrix
consists of only the spatial coefficients in front of the
term in Equations (62)-(71). We use the infinity norm
.
16. Velocity Expressions
The velocity for either
,
or
and
,
,
and
is shown in Appendix. Note that the velocity in the Appendix is based on the general solution with constant
included. There the initial condition at
for large data
has been used and
, where C is an arbitrary constant. We notice that the solution given by Equations (37)-(40) for the Holder continuous function in all spatial variables and time since the Cartesian product space is considered, then the application of the n-finite composition of the function
on this solution for each
will send the finite time singularity to infinity. It can be verified that applying
n-times keeps moving the blowup points further and further to the right on the positive t axis. (recall from section 2: is valid where each term in the expression is zero). Hence no finite time blowup can occur in the limit as
for the fixed point. Note that due to the additive property of the argument of the exponential of the Lambert function W (Equations (37)-(38) in spatial and time variables, together with an arbitrary large data variable
that any finite composition of solutions
will also be solutions of PNS simply by shifting the data term
and constants in the expression in the exponential term. This is true for any n thus in the limit it is proposed that no finite-time blowup at infinity occurs and also no finite time singularites on
can exist.
17. Conclusion
In this present work, the functions
for the Navier Stokes equations on
are proposed to be Hölder continuous when there is one non zero constant amongst
and
and thus, the pressure P is unbounded from below on the infinite interval for t. When on the Cartesian product space, there will be no finite time blowup by applying a sequence of infinite compositions of W functions of
. The limitation of the present work is that although supporting proof is given in [3] for the asymptotic result, future work is necessary to provide proofs from different viewpoint associated with the form of the solution given in this paper. Also, it remains to prove rigorously using induction that the limit
of
will also be a solution of NS equations. In the present work, no finite time blowup is proposed to occur on
.
Appendix 1
The velocity solution obtained in [7] is re-introduced here,
Nomenclature
: space approximating 3-Torus
: composition of functions
: real number strictly less than 0
: Fourier Transform
: eigenvalue
: positive real numbers
: 3-Torus
: Complex field of numbers
: Leray Projector
: Set of all ordered triplets of real numbers
: 3D Space
: line subspace in
: Functional space used in Theorem 1
: Space-Time dependent Functional space used inTheorem 1
: dynamic viscosity
: gradient operator
: Laplacian operator
:
norm
: infinity norm
: kinematic viscosity
: Tensor Product
: constant density of uid
×: cross product
: Bilinear Form
: 1-dimensional ball of radius R at centre
: space of continuous functions on
: vector space of continuously differentiable functions on
: space of in_ntely-times continuously differentiable functions on X
f: forcing in Navier Stokes equation
J: Jacobian
: Space of q integrable functions in space
: Lebesgue space of integrable functions
P: WeierstrassP function
p: fluid pressure
Space of Tempered Distributions
Heat Semigroup
u: fluid velocity
W: LambertW function
Appendix 2. Solution of Equation (29) Subject to Equation (22) and It’s Solution of PDE off and on Subspaces and the Continuity Equation
There exists an inverse condition equation among the following parameters such that
solves Equation (29). It is
(A2.1)
Solving for
it is observed that an inverse relationship exists between it and the constant
for all other constants fixed. This condition ensures that as
the solution remains bounded as
decreases. It is a fundamental and necessary condition for the solution
. The solution for the first
compositions for
is shown in Figure A1.
Figure A1. A sequence of non-contractive non-cauchy functions sending singular points in first derivatives to infinity.
It was seen that
on the subspace
. This is given by Equation (22). Next it is shown that
off of the subspace
. The solution of Equation (29) is,
A more general solution of Equation (29) is written as,
(A2.2)
where
is N compositions of the LambertW function acting on the base solution
. Here from the form in Equation (A2.2) and substituting into Equation (29) also gives a LambertW function solution for
in a similar form as above with different constants. There exists an inverse condition equation among the following parameters such that
solves Equation (29) for any
by mathematical induction.
For any N there exists a pattern when
is substituted into the
PDE. There is a common factor of N compositions of LambertW function for each N in the
equation regardless of the number of compositions performed. This common factor is always zero if and only if
, regardless of the number of compositions performed. This setting to zero for the factor reduces to a vertical shift in the solutions such that the time s where the velocity
has a first derivative blowup at say,
, is precisely where the graph of the function of
is zero. These points are all shifted by the exact same amount regardless of the integer N. See Figure A1 where the shifting is not yet performed but can be visioned by shifting up the curves as they move out to
. When substituting
and
(all equal in s but vary in
) into
one obtains the following factored term for each N and there is a pattern for N-compositions,
Solving for the inner Lambert function, that is,
gives the shift as,