arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1711.04430math.AP
收藏

球对称多维等熵气体动力学的整体熵解

Global Entropy Solutions to Multi-Dimensional Isentropic Gas Dynamics with Spherical Symmetry

Feimin Huang, Tianhong Li, Difan Yuan

摘要:

本文研究了多维可压缩流体欧拉方程的球对称解,它在实际物理中有着广泛的应用。该系统可以归结为具有几何源项的一维等熵气体动力学。由于奇点在原点的存在,很少有论文专门讨论这个问题。本文证明了两个整体熵解的存在性定理。第一种方法主要考虑不允许负速度的原点的情况,第二种方法则对应于包含非负速度的原点的情况。利用$L^\infty$补偿紧性框架和消失粘性方法证明了近似解的收敛性。在第二种情况下,我们表明,如果爆炸波最初向外移动,并且初始密度和速度在原点附近以一定的速率衰减到零,那么对于任何正的时间,密度和速度在原点附近以相同的速率趋于零。特别地,两个存在定理中的熵解关于时间是一致有界的。

英文摘要:

We are concerned with spherically symmetric solutions to the Euler equations for the multi-dimensional compressible fluids, which have many applications in diverse real physical situations. The system can be reduced to one dimensional isentropic gas dynamics with geometric source terms. Due to the presence of the singularity at the origin, there are few papers devoted to this problem. The present paper proves two existence theorems of global entropy solutions. The first one focuses on the case excluding the origin in which the negative velocity is allowed, and the second one is corresponding to the case including the origin with non-negative velocity. The $L^\infty$ compensated compactness framework and vanishing viscosity method are applied to prove the convergence of approximate solutions. In the second case, we show that if the blast wave initially moves outwards and the initial densities and velocities decay to zero with certain rates near origin, then the densities and velocities tend to zero with the same rates near the origin for any positive time. In particular, the entropy solutions in two existence theorems are uniformly bounded with respect to time.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑