Skip to content
BY-NC-ND 4.0 license Open Access Published by De Gruyter Open Access December 27, 2018

The well-posedness of solution to a compressible non-Newtonian fluid with self-gravitational potential

  • Yukun Song EMAIL logo , Shuai Chen and Fengming Liu
From the journal Open Mathematics

Abstract

We study the initial boundary value problem of a compressible non-Newtonian fluid. The system describes the motion of the compressible viscous isentropic gas flow driven by the non-Newtonian self-gravitational force. The existence of strong solutions are derived in one dimensional bounded intervals by constructing a semi-discrete Galerkin scheme. Moreover, the uniqueness of solutions are also investigated. The main point of the study is that the viscosity term and potential term are fully nonlinear, and the initial vacuum is allowed.

MSC 2010: 76N10; 76A05

1 Introduction

In mathematical physics, the Navier-Stokes equation is known as one of the most fundamental equations in fluid mechanics. The compressible isentropic Navier-Stokes equations, which are the basic models describing the evolution of a viscous compressible fluid in a domain xΩ, read as follows:

ρt+div(ρu)=0,(ρu)t+div(ρuu)2div(μD(u))(λdivu)+P(ρ)=0,(1)

where the unknowns ρ, u represent the density and the velocity of the fluid, respectively. Here D(u) = (∇u + (∇u)T)/2 is the strain tensor and P(ρ) = γ (a > 0, γ > 1) is the pressure, μ and λ are the viscosity constants which satisfy the physical requirements μ ≥ 0 and 2μ + 3λ ≥ 0. The Navier-Stokes equations are the equations governing the motion of usual fluids like water, air, oil etc., under quite general conditions, and they appear in the study of many important phenomena, either alone or coupled with other equations. For instance, they are used in theoretical studies in aeronautical sciences, in meteorology, in thermo-hydraulics, in the petroleum industry, in plasma physics, etc. From the point of view of continuum mechanics the Navier-Stokes equations are essentially the simplest equations describing the motion of a fluid, and they are derived under a quite simple physical assumption, namely, the existence of a linear local relation between stresses and strain rates. The compressible isentropic Navier-Stokes equations (1.1) are derived from the conservation laws of mass and the balance of momentum, (for details see [1, 2]). While the physical model leading to the Navier-Stokes equations is simple, the situation is quite different from the mathematical point of view. In particular, because of the nonlinearity, the mathematical study of these equations is difficult and requires the full power of modern functional analysis. A major question is whether the solution remains smooth all the time. These and other related questions are interesting not only for mathematical understanding of the equations but also for understanding the phenomenon of turbulence.

There are huge literatures on the study of the existence and behavior of solutions to Navier-Stokes equations. Some of the previous relevant works in this direction can be summarized as follows. For instance, the 1D version of (1) were addressed by Kazhikhov et al. in [3] for sufficiently smooth data, and by Hoff [4] for discontinuous initial data, where the data is uniformly away from the vacuum; the existence of global weak solutions for isentropic flow were investigated by Lions in [5] by using the weak convergence method. In [6], the authors employed a new method to prove the existence and uniqueness of local strong solutions in the case where the initial data satisfies some compatibility conditions. The dynamics of weak solutions and vacuum states were investigated in [7] for the 1D compressible Navier-Stokes equations with density-dependent viscosity in bounded spatial domains or periodic domains. For other results we refer the reader to [8-13] and the references cited therein.

The above references mainly concerned the fluid which the relation between the stress and rate of strain is linear, namely, the Newtonian fluid. The study of non-Newtonian fluids (the relation between the stess and rate of strain is not linear) mechanics is of great significance because such fluids describe more realistic phenomenon. These flows are frequently encountered in many physical and industrial processes [14], such as porous flows of oils and gases [15], biological fluid flows of blood [16], saliva and mucus, penetration grouting of cement mortar and mixing of massive particles and fluids in drug production [17]. Many studies are based on the field of non-Newtonian flows, both theoretically and experimentally. In [18], Ladyzhenskaya first proposed a special form for the incompressible model, namely that the viscous stress tensor Γij = (μ0 + μ1|E(∇u)p−2|)Eij(∇u). For μ0 = 0, if p < 2, it is a pseudo-plastic fluid, and when p > 2, it is a dilatant fluid (see also [19]). From a Physics point of view, the model captures the shear thinning fluid for the case of 1 < p < 2, and captures the shear thickening fluid for the case of p > 2. In [20], the trajectory attractor and global attractor for an autonomous non-Newtonian fluid in dimension two was studied. The existence and uniqueness of solutions for non-Newtonian fluids were established in [21] by applying the Ladyzhenskaya’s viscous stress tensor model. Then the global existence and exponential stability of solutions to the one-dimensional full non-Newtonian fluids were investigated in [22]. Recently, in [23], the authors present a decoupling multiple-relaxation-time lattice Boltzmann flux solver for simulating non-Newtonian power-law fluid flows.

On the other hand, another basiclly important case is when the motion of compressible viscous isentropic flow is driven by a self-gravitational force. However, at the present, little is known yet on the strong solutions to system (1) with non-Newtonian self-gravitational potential on bounded domain, even in one dimensional case. In this paper we focus on the following 1D system of compressible non-Newtonian equations

ρt+(ρu)x=0,(ρu)t+(ρu2)x+ρΦxλ(|ux|p2ux)x+Px=0,((Φx2+μ0)q22Φx)x=4πg(ρ1|Ω|Ωρdx)(2)

in ΩT = Ω × (0, T) with the initial and boundary conditions

(ρ,u)|t=0=(ρ0,u0),xΩ,(3)
u(x,t)|Ω=Φ(x,t)|Ω=0,t[0,T].(4)

Here, ρ, u, Φ denote the density, velocity and the non-Newtonian gravitational potential, respectively. P = γ (a > 0, γ > 1) is the pressure, the initial density ρ00,43<p<2,q>2 are given constants. Our purpose is to some further light on problem (2)-(4). When 1 < p < 2, the second equation of (2) always has singularity. Secondly, we emphasize that the vacuum of initial density may exist. In the presence of vacuum, the parabolicity is lost. Moreover, the equations are strongly coupled with each other. We will investigate the existence and uniqueness of local strong solutions of (2)-(4) by overcoming the above difficulties, and the proof is inspired by the previous work in [6] and [21].

We state the main results as follows:

Theorem 1.1

Assume that (ρ0, u0) satisfies the following conditions

0ρ0H1(Ω),u0H01(Ω)H2(Ω).

If there is a functiongL2(Ω), such that the initial data satisfy the following compatibility condition:

[|u0x|p2u0x]x+Px(ρ0)=ρ012g,fora.e.xΩ,

then there exist a time T* ∈ (0, +∞) and a unique strong solution (ρ, u, Φ) to (2)-(4) such that

ρL([0,T];H1(Ω)),ρtL([0,T];L2(Ω)),utL2(0,T;H01(Ω)),ΦL(0,T;H2(Ω)),ΦtL(0,T;H1(Ω)),ρutL(0,T;L2(Ω))uffj(0,T;W01,p(Ω)H2(Ω)),(|ux|p2ux)xL2([0,T];L2(Ω)).

The rest of the paper is organized as follows. After stating the notations, in Section 2, we first present some useful lemmas, then the analysis of a priori estimates for smooth solutions are derived. In Section 3, we give the proof of existence, and finally complete the proof of uniqueness of the main theorem in Section 4.

In what follows, we use the following abbreviations for simplicity of notation:

H1=H1(Ω),Lp=Lp(Ω),||L2=L2(Ω),||L=L(Ω).

Throughout this paper, we will omit the variables t, x of functions if it does not cause any confusion. We use C to denote a generic constant that may vary in different estimates.

2 A priori estimates for smooth solutions

In this section, we provide some known facts that will be used in the proof of the main result.

Lemma 2.1

([24]). LetΩbe bounded set inR1, and 1 ≤ qp ≤ +∞. Then

uLq(Ω)|Ω|1q1puLp(Ω).

Lemma 2.2

([21]). Letρ0H1(Ω), u0H01(Ω) ∩ H2(Ω), gL2(Ω) andu0εH01(Ω)H2(Ω)be a solution of the boundary value problem

[(ε(u0x)2+1(u0x)2+ε)2p2u0x]x+Px(ρ0)=(ρ0)12gu0|Ω=0.

Then there is a subsequences{u0εj},j=1,2,3,of{u0ε},asεj0,

u0εju0inH01(Ω)H2(Ω),[(εj(u0xεj)2+1(u0xεj)2+εj)2p2u0xεj]x(|u0x|p2u0x)xinL2(Ω).

To prove the existence of strong solutions, we require some more regular estimates. Next, we derive some a priori estimates for smooth solutions which are crucial to prove the local existence of strong solutions.

Let (ρ, u, Φ) be a smooth solution of (2)-(4) and ρ0δ, where 0 < δ ≪ 1 is a positive number, m0 := ∫Ωρ0(x)dx be initial mass and m0 > 0. Throughout the paper, we will denote

M0=1+μ0+μ01+|ρ0|H1+|g|L2.

As stated above, we need to estimate the uniform bound of the approximate solutions. Now, we consider the following linearized problem

ρt+(ρu)x=0,(5)
(ρu)t+(ρu2)x+ρΦx+Lpu+Px=0,(6)
LqΦ=4πg(ρ1|Ω|Ωρdx)(7)

with the initial and boundary conditions

(ρ,u)|t=0=(ρ0,u0),xΩ(8)
u(x,t)|Ω=Φ(x,t)|Ω=0,t[0,T](9)

where

Lpu=[(εux2+1ux2+ε)2p2ux]x,LqΦ=((Φx)2+μ0)q22Φx)x

and u0H01H2 is the smooth solution of the boundary value problem

[(εu0x2+1u0x2+ε)2p2u0x]x+Px(ρ0)=ρ012gu0|Ω=0.(10)

We will prove the existence of solutions for (5)-(9) by virtue of the uniform estimates which do not depend on ε, depending only on M0, and prove the limit of the approximate solutions is the solution of problem (2)-(4) with vacuum.

It follows from (10) and Young’s inequality that there exists a constant C depending only on M0, such that

|u0xx|L2C(1+|ρ0|L12|g|L2+|Px(ρ0)|L2)1p1C.

We construct an auxiliary function

Ψ(t)=1+|ρ(s)|H1(Ω)+|u(s)|W01,p(Ω)+|ρut(s)|L2(Ω))

Our derivation will be based on the local boundedness of Ψ(t). Before we estimate each term of Ψ, we need to do the estimate of |uxx|L2. Firstly, multiplying (7) by Φ and integrating over Ω and using Young’s inequality,

Ω|Φx|qdxC(m0).(11)

Then, it follows from equation (6) and (5) that

|uxx|1p1(|ux|2p+1)|ρut+ρuux+ρΦx+Px|.

Taking it by L2-norm, using Young’s inequality, we obtain

|uxx|L2p1C[1+|ρut|L2+|ρuux|L2+|ρΦx|L2+|Px|L2]C[1+|ρ|L12|ρut|L2+(|ρ|L|ux|Lpp2+1)2(p1)3p4+|ρ|L|Φx|Lq+|Px|L2+12|uxx|L2p1

which along with (11), implies that

|uxx(t)|L2CΨ6γ3p4(t).(12)

Estimate for |ρ|H1

We are going to estimate the first term of Ψ(t). Multiplying (5) by ρ and integrating over Ω with respect to x, we obtain from Sobolev inequality

ddt|ρ(t)|L22|uxx|L2|ρ|L22.(13)

Differentiating (5) with respect to x, multiplying it by ρx and integrating over Ω on x, and using Sobolev inequality, we have

ddtΩ|ρx|2dx=Ω[32ux(ρx)2+ρρxuxx](t)dx3|ρx|L22|uxx|L2.(14)

Together with (13), (14) and Gronwall’s inequality, it follows that

sup0tT|ρ(t)|H12Cexp(C0tΨ6γ3p4(s)ds).(15)

Using (5) we obtain

|ρt(t)|L2|ρx(t)|L2|u(t)|L+|ρ(t)|L|uxx(t)|L2CΨ6γ+23p4(t).(16)

Besides, differentiating (7) with respect to time t, multiplying it by Φt and integrating over Ω with respect to x and using Young’s inequality, we have

|Φxt|L22CΨ4(t),(17)

where C is a positive constant depending only on M0.

Estimate for |u|W01,p

We turn to the second term of Ψ(t). Multiplying (6) by ut, integrating over ΩT, together with (5), (10), Sobolev inequality and Young’s inequality, we obtain

0t|ρut(s)|L22(s)ds+|ux(t)|LppΩT(|ρuuxut|+|ρΦxut|+|Pxuux|+γ|Pux2|)dxds+Ω(|Pux|dx+γ|Pux2|)dxds+CC(1+ΩΨ24γ3p4(s)ds).(18)

In the second inequality we have used

|ρ(t)|L+|P(t)|H1|ρ(t)|H1+C|ρ(t)|Lγ1|ρ(t)|H1CΨγ(t).Ω|P(t)|pp1dx=Ω|P(0)|pp1dx+0ts(ΩP(s)pp1dx)dsC+CΩ|ρ(s)|Lγ1|P(s)|L1p1|ρ(s)|H1|ux(s)|LpdsC(1+ΩΨ2γ+1p1(s)ds),

where C is a positive constant, depending only on M0.

Estimate for |ρut|L2

We estimate the last term of Ψ(t). Differentiating (6) with respect to t yields

ρutt+ρuuxt[(εux2+1ux2+ε)2p2ux]xt=(utuuxΦx)ρtρutuxρΦxtPxt.

Multiplying it by ut and integrating over Ω with respect to x, we derive

12ddtΩρ|ut|2dx+Ω[(εux2+1ux2+ε)2p2ux]tuxtdx=Ω[ρt(utuuxΦx)ρutuxρΦxt]utdx+ΩPtuxtdx.(19)

Note that

Ω[(εux2+1ux2+ε)2p2ux]tuxtdx(p1)Ω(ux2+1)p22|uxt|2dx.(20)

Let

β=(ux2+1)p24.

From (12), it follows that

|β1|L=|(ux2+1)2p4|LC(|uxx|L22p2+1)CΨ(p+4)(p1)(2p)γ2(3p4)CΨ3γ3p4.

Then, from (20) and (5), (19) can be rewritten as

12ddtΩρ|ut|2dx+(p1)Ω|βuxt|2dxΩ2ρ|u||ut||uxt|dx+Ω|ρx||u|2|ux||ut|dx+Ωρ|u||ux|2|ut|dx+Ω|Px||u||uxt|dx+ΩγP|ux||uxt|dx+Ω|ρx||u||Φx||ut|dx+Ωρ|ux||Φx||ut|dx+Ωρ|ut||ux||ut|dx+Ωρ|Φxt||ut|dx=j=19Ij.(21)

Using Sobolev inequality, Young’s inequality, (6) and (12), we obtain

I12|ρ|L12|u|L|ρut|L2|βuxt|L2|β1|LCΨ16γ3p4(t)+p16|βuxt|L22,I2|ρx|L2|u|L2|ux|Lpp|ux|L1p2|ut|L|ρx|L2|ux|Lp2+p|uxx|L21p2|βuxt|L2|β1|LCΨ23γ3p4(t)+p16|βuxt|L22,I3|ρ|L212|u|L||ux|L2|ρut|L2CΨ22γ3p4(t),I4|Px|L2|u|L|βuxt|L2|β1|LCΨ14γ3p4(t)+p16|βuxt|L22,I5C|P|L2|ux|L|βuxt|L2|β1|LCΨ22γ3p4(t)+p16|βuxt|L22,I6|ρx|L2|u|L|Φx|L2|ut|L|ρx|L2|ux|Lp|Φx|Lq|βuxt|L2|β1|LCΨ14γ3p4(t)+p16|βuxt|L22,I7|ρ|L12|ux|L|Φx|L2|ρut|L2|ρ|L12|uxx|L2|Φx|Lq|ρut|L2CΨ18γ3p4(t),I8|ρut|L22|ux|L|CΨ16γ3p4(t),I9|ρ|L2|Φxt|L2|ut|L|ρ|L2|Φxt|L2|βuxt|β1|LCΨ18γ3p4+p16|βuxt|L22.

Substituting Ij(j = 1, 2, …, 9) into (21) and integrating over (τ, t) ⊂ (0, T), we have

|ρut(t)|L22+(p1)τt|βuxt|L22(s)dsCτtΨ23γ3p4(s)ds+|ρut(τ)|L22.(22)

Next, we estimate limτ0|ρkutk(τ)|L22.

Multiplying (6) by ut and integrating over Ω, we obtain

Ωρ|ut|2dx2Ω(ρ|u|2|ux|2+ρ|Φx|2+ρ1|Lpu+Px|2)dx.

Since (ρ, u, Φ) is a smooth solution, we have

limτ0Ω(ρ|u|2|ux|2+ρ|Φx|2+ρ1|Lpu+Px|2)dx=Ω(ρ0|u0|2|u0x|2+ρ0|Φ0x|2+|g|2)dx|ρ0|L|u0|L2|u0x|L22+|ρ0|L|Φ0x|L22+|g|L22.

Then taking a limit on τ for (22) as τ → 0, we get

|ρut(t)|L22+0t|βuxt|L22(s)dsC(1+0tΨ23γ3p4(s)ds),(23)

which combined with (12), (15)-(17), (18) and the definition of Ψ(t) leads to

Ψ(t)Cexp(C~0tΨ6γ3p4(s)ds),

where C, are positive constants, depending only on M0.

In view of this inequality, we can find a time T* > 0 and a constant C, such that

sup0tT1(|ρ|H1+|u|W01,pH2+|ρut|L2+|ρt|L2+0T(|uxt(s)|L22)dsC,

where C is a positive constant depending only on M0.

3 Proof of the existence

Since a priori estimates for higher regularity have been derived, the existence of strong solutions can be established by a standard argument, in the case of bounded domains, we construct approximate solutions via a semi-discrete Galerkin scheme, derive uniform bounds and thus obtain solutions by passing to the limit. Our method that constructed approximate systems is similar to that in [6]. To implement a semi-discrete Galerkin scheme, we take our basic function space as X = H01(Ω) ∩ H2(Ω) and its finite-dimensional subspaces as X = span{,1, ,2, Π, ,m} ⊂ XC2(Ω). Hence φm is the mth eigenfunction of the general elliptic operator defined on X.

Let ρ0, u0, Φ0, and f be functions satisfying the hypothes of theorem, assume for the moment that ρ0δC(Ω) and ρ0δδ in Ω for some constant δ > 0. We can construct an approximate solution for any vXm, φC2(Ω), such that

ρtm+(ρmum)x=0,Ω(ρmutm+ρmumuxm+ρmΦxm+Lpum+Pxm)vdx=0,ΩLqΦmϕdx=4πgΩ(ρmm0|Ω|)ϕdx.

The initial and boundary conditions are

u0mk=1m(u0,φk)L2(Ω)φk,ρm(0)=ρ0δ,ρδ<|ρ0|L(Ω)+1,|ρ0δρ0|H1(Ω)0,um|Ω=Φm|Ω=0.

Under the hypotheses of the theorem, similarly, for any fixed δ > 0, we may get the similar estimate

sup0tT1(|ρm|H1+|um|W01,pH2+|ρmutm|L2+|ρtm|L2+0T(|uxtm(s)|L22)dsC.(24)

Since C does not depend on ε, δ and m (for any m > M, M is dependent on the approximate velocity of the initial condition). We can deduce from the uniform estimate(24) that (ρm, um, Φm) converges, up to an extraction of subsequences. Let m → ∞. We obtain the following estimates in the obvious weak sense

sup0tT1(|ρδ|H1+|uδ|W01,pH2+|ρδutδ|L2+|ρtδ|L2+0T(|uxtδ(s)|L22)dsC.

For each small δ > 0, ρ0δ = Jδ * ρ0 + δ is a mollifier on Ω, and u0δH01(Ω)H2(Ω) is the unique solution of the boundary value problem

[(ε(u0xδ)2+1(u0xδ)2+ε)2p2u0xδ]x+Px(ρ0δ)=(ρ0δ)12gδu0δ|Ω=0,(25)

where gδC0,and|gδ|L2(Ω)|g|L2(Ω),limδ0+|gδg|L2=0.

We deduce that (ρδ, uδ, Φδ) is a solution of the following initial and boundary value problem

ρt+(ρu)x=0,(ρu)t+(ρu2)x+ρΦxλ(|ux|p2ux)x+Px=0,((Φx2+μ0)q22Φx)x=4πg(ρ1|Ω|Ωρdx)(ρ,u)|t=0=(ρ0δ,u0δ),u(x,t)|Ω=Φ(x,t)|Ω=0,

where 43<p<2,q>2.

Together with Lemma 2.2, there is s subsequence {uεj,δ}of{uε,δ},asεj0,{u0εj,δ}u0δinH01(Ω)H2(Ω). Also there is a subsequence {u0δj}of{u0δ}, such that as δj0+,u0δju0inH01(Ω)H2(Ω). With ρ0δ = Jδ * ρ0 + δ, we have, as δj0+,Px(ρ0δj)(ρ0δj)12gδjPx(ρ0)(ρ0)12ginL2(Ω). By (25), there exists a subsequence {u0δj}of{u0δ}, such that as δj0+,(|u0xδj|p2u0xδj)x(|u0x|p2u0x)xinL2(Ω). Hence, u0H01(Ω) ∩ H2(Ω) satisfies equation (|u0x|p2u0x)x+Px(ρ0)=(ρ0)12g for a.e. xΩ and is a unique solution. According to above uniform estimates, by the lower semi-continuity of various norms, we have

sup0tT1(|ρ|H1+|u|W01,pH2+|ρut|L2+|ρt|L2+0T(|uxt(s)|L22)dsC

where C is a positive constant depending only on M0.

4 Proof of the uniqueness

We now prove the uniqueness results. Let (ρ, u, Φ), (ρ̄, ū, Φ̄) be two solutions of the problem (2)-(4). Combining (2)1 and (2)2,

(ρu)t+(ρu2)x+ρΦx+(|ux|p2ux)x+Px=0,(ρ¯u¯)t+(ρ¯u¯2)x+ρ¯Φ¯x+(|u¯x|p2u¯x)x+P¯x=0,

we show that

ρ(uu¯)t+ρu(uu¯)x[(|ux|p2ux)x(|u¯x|p2u¯x)x]=(ρρ¯)(u¯tu¯u¯xΦ¯x)(PP¯)xρ(ΦΦ¯)xρ(uu¯)u¯x.

Multiplying the above equation by (uū) and integrating over Ω, we obtain

12ddtΩρ(uu¯)2dx+Ω(|ux|p2ux|u¯x|p2u¯x)(uu¯)xdxΩ{|ρρ¯||u¯tu¯u¯xΦ¯x||uu¯|+|PP¯||(uu¯)x|+ρ|(ΦΦ¯)x||uu¯|+ρ|uu¯|2|u¯x|}dx|ρρ¯|L2|u¯tu¯u¯xΦ¯x|L2|uu¯|L+|PP¯|L2|(uu¯)x|L2+|ρ|L|(ΦΦ¯)x|L2|uu¯|L2+|ρ(uu¯)|L22|u¯x|L|ρρ¯|L22(C+C|u¯t|L22)+C|PP¯|L22+|ρ(uu¯)|L22+ε|(uu¯)x|L22.(26)

Since

Ω(|ux|p2ux|u¯x|p2u¯x)(uu¯)xdx=1p1Ω(01|θux+(1θ)u¯x|p2dθ)(uu¯)x2dx01|θux+(1θ)u¯x|p2dθ011(|ux|+|u¯x|)2pdθ=1(|ux|+|u¯x|)2p.

Thus

Ω(|ux|p2ux|u¯x|p2u¯x)(uu¯)xdx1(|ux|L(0,t;L(I))+|u¯x|L(0,t;L(I)))2pΩ(uu¯)x2dx1CΩ(uu¯)x2dx.

Moreover, from (2)3, by a direct calculation, we have

((Φx2+μ0)q22Φx)x((Φ¯x2+μ0)q22Φ¯x)x=4πg(ρρ¯).

Multiplying it by (ΦΦ̄) and integrating over Ω, we obtain

Ω[(Φx2+μ0)q22Φx(Φ¯x2+μ0)q22Φ¯x](ΦΦ¯)xdx=Ω4πg(ρρ¯)(ΦΦ¯)xdxC|ρρ¯|L2+ε|(ΦΦ¯)x|L2.(27)

Note that

Ω[(Φx2+μ0)q22Φx(Φ¯x2+μ0)q22Φ¯x](ΦΦ¯)xdx=Ω[01ω(θΦx+(1θ)Φ¯x)dθ](ΦxΦ¯x)2dx,(28)
ω(s)=[(s2+μ0)q22s]=(s2+μ0)p42((p1)s2+μ0)μ0p22.

Together with (27) and (28), we arrive at |(ΦΦ¯)x|L22C|ρρ¯|L22.

Consequently, (26) can be rewritten as

12ddt|ρ(uu¯)(t)|L22+1C|uxu¯x|L22ds|ρρ¯|L22(C+C|u¯t|L22)+C|PP¯|L22+|ρ(uu¯)|L22.(29)

On the other hand, from the conservation of mass equation (2)1, using the identity

(ρρ¯)t+(ρρ¯)xu+ρ¯x(uu¯)+(ρρ¯)ux+ρ¯(uxu¯x)=0.(30)

Multiplying the above equation by (ρρ̄) and integrating it over Ω, we obtain

12ddtΩ(ρρ¯)2dx+Ω12(ρρ¯)2uxdx+Ωρ¯x(uu¯)(ρρ¯)dx+Ω(ρρ¯)2uxdx+Ωρ¯(uu¯)x(ρρ¯)dx=0.

Thus

12ddtΩ(ρρ¯)2dxC(|ux|L|ρρ¯|L22+|ρx|L2|uu¯|L|ρρ¯|L2+|ρ¯|L|(uu¯)x|L2|ρρ¯|L2)C|ρρ¯|L22+C(ϵ)|(uu¯)x|L22.(31)

Furthermore, (5)1 implies

(PP¯)t+(PP¯)xu¯+P¯x(uu¯)+γ(PP¯)ux+γP¯(uu¯)x=0.

Multiplying it by (P) and integrating over Ω, we get

12ddtΩ(PP¯)2dx=12Ω(PP¯)2uxdx+ΩP¯x(uu¯)(PP¯)dxγΩ(PP¯)2uxdx+γΩP¯(uu¯)x(PP¯)dx(C|ux|L|PP¯|L22+C|P¯|H1|uu¯|L|PP¯|L2)(C(|ux|L+|P¯|H1+1)|PP¯|L22)ds+ε|(uu¯)x|L22.(32)

From(29)-(32), we obtain

ddtΩ(ρ(uu¯)2+(ρρ¯)2+(PP¯)2)dx+Ω(uu¯)x2dxC((1+|u¯t|L22+|u¯x|L2+|ρ|H12+|ux|L+|P¯x|L22)(|ρ(uu¯)|L22+|(ρρ¯)|L22+|(PP¯)|L22).

From this and the Grownwall’s inequality, yields

|ρ(uu¯)|L22+|ρρ¯|L22+|PP¯|L22=0

which means

u=u¯,ρ=ρ¯,Φ=Φ¯.

This complete the proof of the main theorem.

Acknowledgement

The authors would like to thank the anonymous referees for their valuable suggestions and comments. This work was supported by the National Natural Science Foundation of China (Nos. 11526105; 11572146), the Education Department Foundation of Liaoning Province (No. JQL201715411) and the Natural Science Foundation of Liaoning Province (No. 20180550585).

References

[1] Chorin A. J., Marsden J. E., A Mathematical Introduction to Fluid Mechanics, Springer-Verlag, New York, (1993).10.1007/978-1-4612-0883-9Search in Google Scholar

[2] Teman R., Navier-Stokes Equations, Theory and Numerical Analysis, North-Holland, Amsterdam, (1984).Search in Google Scholar

[3] Kazhikhov A. V., Shelukhin V V: Unique global solution with respect to time of initial-boundary value problems for one-dimensional equations of a viscous gas. J. Appl. Math. Mech., 1977, 41(2), 273-282.10.1016/0021-8928(77)90011-9Search in Google Scholar

[4] Hoff D., Global existence for 1D, compressible, isentropic Navier-Stokes equations with large initial data. Trans. Amer. Math. Soc., 1987, 303(1), 169-181.10.1090/S0002-9947-1987-0896014-6Search in Google Scholar

[5] Lions P. L., Mathematical topics in fluids mechanics, Vol.2, Oxford Lecture Series in Mathematics and Its Applications, Vol. 10, Clarendon Press, Oxford, (1998).Search in Google Scholar

[6] Choe H., Kim H., Strong solutions of the Navier-Stokes equations for isentropic compressible fluids, J.Differential Equations, 2003, 190, 504-523.10.1016/S0022-0396(03)00015-9Search in Google Scholar

[7] Li H. L., Li J., Xin Z. P., Vanishing of vacuum states and blow-up phenomena of the compressible Navier-Stokes equations, Commun. Math. Phys, 2008, 281, 401-444.10.1007/s00220-008-0495-4Search in Google Scholar

[8] Xin Z. P., Blow up of smooth solutions to the compressible Navier-Stokes equation with compact density, Comm. Pure Appl. Math., 1998, 51, 229-240.10.1002/(SICI)1097-0312(199803)51:3<229::AID-CPA1>3.0.CO;2-CSearch in Google Scholar

[9] Jiang S., Large-time behavior of solutions to the equations of a one-dimensional viscous polytropic ideal gas in unbounded domains. Commun. Math. Phys., 1999, 200, 181-193.10.1007/s002200050526Search in Google Scholar

[10] Feireisl E., Novotný A., Petzeltová H., On the existence of globally defined weak solution to the Navier-Stokes equations, J. Math. Fluid Mech., 2001, 3, 358-392.10.1007/PL00000976Search in Google Scholar

[11] Jiang S., Zhang P., On spherically symmetric solutions of the compressible isentropic Navier-Stokes equations, Commun. Math. Phys., 2001, 215, 559-581.10.1007/PL00005543Search in Google Scholar

[12] Yin J. P., Tan Z., Local existence of the strong solutions for the full Navier-Stokes-Poisson equations, Nonlinear Anal., 2009, 71, 2397-2415.10.1016/j.na.2009.01.074Search in Google Scholar

[13] Li J., Liang Z. L., Some uniform estimates and large-time behavior of solutions to one-dimensional compressible Navier-Stokes systems in unbounded domains with large data, Arch. Rational Mech. Anal., 2016, 220, 1195-1208.10.1007/s00205-015-0952-0Search in Google Scholar

[14] Chhabra R. P., Richardson J. F., Non-Newtonian Flow and Applied Rheology (Second Edition), Oxford, (2008).Search in Google Scholar

[15] Chevalier T., Rodts S., Chateau X., Chevalier C. and Coussot P., Breaking of non-Newtonian character in flows through a porous medium, Physical Review E, 2014, 89, 023002.10.1103/PhysRevE.89.023002Search in Google Scholar PubMed

[16] Yun B. M., Dasi L. P., Aidun C. K. and Yoganathan A. P., Computational modelling of flow through prosthetic heart valves using the entropic lattice-Boltzmann method, Journal of Fluid Mechanics, 2014, 743, 170-201.10.1017/jfm.2014.54Search in Google Scholar

[17] Gachelin J., Mino G., Berthet H., Lindner A., Rousselet A. and Clement E., Non-Newtonian viscosity of Escherichia coli suspensions, Physical Review Letters, 2013, 110, 268103.10.1103/PhysRevLett.110.268103Search in Google Scholar PubMed

[18] Ladyzhenskaya O. A., New equations for the description of viscous incompressible fluids and solvability in the large of the boundary value problems for them. In Boundary Value Problems of Mathematical Physics, vol. V, Amer. Math. Soc., Providence, RI. (1970) 95-118.Search in Google Scholar

[19] Böhme G., Non-Newtonian fluid Mechanics, Appl.Math.Mech., North-Holland, Amsterdam (1987).Search in Google Scholar

[20] Zhao C., Zhou S., Li Y., Trajectory attractor and global attractor for a two-dimensional incompressible non-Newtonian fluid. J. Math. Anal. Appl., 2007, 325, 1350-1362.10.1016/j.jmaa.2006.02.069Search in Google Scholar

[21] Yuan H. J., Xu X. J., Existence and uniqueness of solutions for a class of non-Newtonian fluids with singularity and vacuum, J. Differential Equations, 2008, 245, 2871-2916.10.1016/j.jde.2008.04.013Search in Google Scholar

[22] Qin Y., Liu X., Yang X., Global existence and exponential stability of solutions to the one-dimensional full non-Newtonian fluids. Nonlinear Anal., Real World Appl., 2012, 13, 607-633.10.1016/j.nonrwa.2011.07.053Search in Google Scholar

[23] Wang Y., Shu C., Yang L. M., Yuan H. Z., A Decoupling Multiple-Relaxation-Time Lattice Boltzmann Flux Solver for Non-Newtonian Power-Law Fluid Flows, Journal of Non-Newtonian Fluid Mechanics, 2016, 235, 20-28.10.1016/j.jnnfm.2016.03.010Search in Google Scholar

[24] Málek J., Nečas J., Rokyta M., Ru̇žička M., Weak and Measure-Valued Solutions to Evolutionary PDEs. Chapman and Hall, New York, (1996).10.1007/978-1-4899-6824-1Search in Google Scholar

Received: 2018-04-10
Accepted: 2018-11-15
Published Online: 2018-12-27

© 2018 Song et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Downloaded on 29.3.2024 from https://www.degruyter.com/document/doi/10.1515/math-2018-0122/html
Scroll to top button