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Global Existence Of Spherically Symmetric Solutions For A Nonlinear Compressible Navier-Stokes Equations

Posted on:2008-11-22Degree:MasterType:Thesis
Country:ChinaCandidate:S L WenFull Text:PDF
GTID:2120360215972678Subject:Applied Mathematics
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In this paper we discuss the global existence of solutions for the nonlinear compressible Navier-Stokes equations with external forces and initial-boundary conditions. I.e., when the external forces f(∫0x udy,t)≠0, g(∫0x udy,t)≠0, (x,t)∈[0,L]×[0,∞) and f(∫0x udy, t)≠const, g(∫0x udy, t)≠const, equations: ut-(rn-1v)x=0, vt-rn-1(β(rn-1v)x/u-Rθ/u)x=f(∫0x udy,t), Cvθt-k(r2n-2θx/u)x-1/u(β(rn-1v)x-Rθ](rn-1v)x+2μ(n-1)(rn-2v2)x2=g(∫<sup>x0 udy, t). With initial-boundary conditions. We will show the global existence of solutions in space H1, H2, H4.This paper has four part: chapter one is introduction, involve the model we investigated, the results correlation this paper, and denotations we used; Chapter two to chapter four is the important content, involve the theorems and proves.The new results we have are four aspects: 1, the solution u has uniform positive lower and upper bounds. 2, the global existence of solutions in space H1. 3, the global existence of solutions in space H2. 4, the global existence of solutions in space H4.The main difference between this paper and others is the externat forces. This paper applied energy method, by some important inequalities, obtained a uniform priori estimates, finally gained the results.
Keywords/Search Tags:Global existence, A uniform priori estimates
PDF Full Text Request
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