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Research On The Blow-up Problem For 2-D Boussinesq Equations In A Bounded Domain

Posted on:2008-10-31Degree:MasterType:Thesis
Country:ChinaCandidate:L H HuFull Text:PDF
GTID:2120360242493924Subject:Mathematics
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This paper focuses mainly on the 2-D Boussinesq equations,which is a classicPDE model in atmosphere and Ocean fluid mechanics and in mathematical fluid me-chanics.In the paper,we successfully extend the serials of results for 2-D Boussi-nesq equations.such as the local-in-time existence and uniqueness of weak solutions inSobolev space and blow-up criterions,from R2 to a bounded domainΩ.First,as for the local-in-time existence and uniqueness.we make use ofHelmholtz-Hodge orthogonal theorem to transfer Boussinesq equations to a nonlinearevolution equation Ut+A(t,U)=0.By virtue of some qualities of the nonlinearoperator F(u,v)=(u·(?))v,we get some useful estimates for the nonlinear oper-ator A(t,U),which helps us to conclude the local-in-time existence and uniquenessof solutions.Then,concerning on the blow-up criterions of weak solutions of Boussinesq equa-tions,we use energy methods,Sobolev inequalities and Gronwall inequality,to control‖θ‖Hs(Ω) and‖u‖Hs(Ω) by‖(?)θ‖L∞(Ω) and‖(?)u‖L∞(Ω).Furthermore,‖(?)θ‖L∞(Ω) cancontrol‖(?)u‖L∞(Ω) by using the vorticity transportation equation.At last,‖(?)θ‖L∞(Ω)can be controlled by‖(?)θ‖M?(Ω).Thus,we can find a blow-up criterion in form of(?)....
Keywords/Search Tags:Boussinesq Equations, Nonlinear Evolution Equations, Existence and Uniqueness, M_φSpace, Blow-up Criterion
PDF Full Text Request
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