arXiv subjects

Daoyuan Fang

Publications and source records attributed to Daoyuan Fang.

41 records · Page 3Linked to original sources

arXiv2007

Global Behavior of Spherically Symmetric Navier-Stokes Equations with Degenerate Viscosity Coefficients

In this paper, we study a free boundary problem for compressible spherically symmetric Navier-Stokes equations with a gravitational force and degenerate viscosity coefficients. Under certain assumptions that imposed on the initial data, we obtain the global existence and uniqueness of the weak solution and give some uniform bounds (with respect to time) of the solution. Moreover, we obtain some stabilization rate estimates in $L^\infty$-norm and weighted $H^1$-norm of the solution. The results show that such system is stable under the small perturbations, and could be applied to the astrophysics.

math.AP↗

arXiv2007

Global Behavior of Spherically Symmetric Navier-Stokes Equations with Density-Dependent Viscosity

In this paper, we study a free boundary problem for compressible spherically symmetric Navier-Stokes equations without a solid core. Under certain assumptions imposed on the initial data, we obtain the global existence and uniqueness of the weak solution, give some uniform bounds (with respect to time) of the solution and show that it converges to a stationary one as time tends to infinity. Moreover, we obtain the stabilization rate estimates of exponential type in $L^\infty$-norm and weighted $H^1$-norm of the solution by constructing some Lyapunov functionals. The results show that such system is stable under the small perturbations, and could be applied to the astrophysics.

math.AP↗

arXiv2007

Existence and uniqueness results for viscous, heat-conducting 3-D fluid with vacuum

We consider the 3-D full Navier-Stokes equations whose the viscosity coefficients and the thermal conductivity coefficient depend on the density and the temperature. We prove the local existence and uniqueness of the strong solution in a domain $Ω\subset\mathbb{R}^3$. The initial density may vanish in an open set and $Ω$ could be a bounded or unbounded domain. We also prove a blow-up criterion for the solution. Finally, we show the blow-up of the smooth solution to the compressible Navier-Stokes equations in $\mathbb{R}^n$ ($n\geq1$) when the initial density has compactly support and the initial total momentum is nonzero.

math.AP↗

arXiv2007

L^2-concentration phenomenon for Zakharov system below energy norm

In this paper, we'll prove a L^2-concentration result of Zakharov system in space dimension two, with radial initial data (u_0,n_0,n_1)\in H^s\times L^2\times H^{-1} ({16/17}<s<1), when blow up of the solution happens by I-method. In additional to that we find a blow up character of this system. Furthermore, we improve the global existence result of Bourgain's to above spaces.

math.AP↗

arXiv2005

Some Remarks on Strichartz Estimates for Homogeneous Wave Equation

We give several remarks on Strichartz estimates for homogeneous wave equation with special attention to the cases of $L^\infty_x$ estimates, radial solutions and initial data from the inhomogeneous Sobolev spaces. In particular, we give the failure of the endpoint estimate $L^4_t L^\infty_x$ for $n=2$.

math.AP↗