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arXiv 1504.02584math.AP
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定常Boltzmann和Navier-斯托克斯方程

The Steady Boltzmann and Navier-Stokes Equations

Kazuo Aoki, François Golse, Shingo Kosuge

摘要:

本文讨论了定常Boltzmann方程和定常不可压Navier-斯托克斯方程在有界区域上的数学理论的异同。首先,我们讨论了两个不同的标度极限,其中定常Boltzmann方程的解具有由定常Navier-Stokes Fourier系统描述的渐近行为。这个系统是否包括粘性加热项取决于弗劳德数与气流马赫数的比值。具有光滑无发散外力的定常Navier-斯托克斯方程总是至少有一个光滑解,而具有相同外力的Boltzmann方程在环面上,或在边界有气体分子镜面反射的有界区域上可能没有任何解,除非力场为零。在这种情况下,粘性加热似乎是至关重要的。在这种情况下,玻尔兹曼方程的任何稳定的解决方案的不存在似乎与温度的增加的演化问题,一种现象,我们已经建立了与数值模拟的帮助下,玻尔兹曼方程和BGK模型。

英文摘要:

The paper discusses the similarities and the differences in the mathematical theories of the steady Boltzmann and incompressible Navier-Stokes equations posed in a bounded domain. First we discuss two different scaling limits in which solutions of the steady Boltzmann equation have an asymptotic behavior described by the steady Navier-Stokes Fourier system. Whether this system includes the viscous heating term depends on the ratio of the Froude number to the Mach number of the gas flow. While the steady Navier-Stokes equations with smooth divergence-free external force always have at least one smooth solutions, the Boltzmann equation with the same external force set in the torus, or in a bounded domain with specular reflection of gas molecules at the boundary may fail to have any solution, unless the force field is identically zero. Viscous heating seems to be of key importance in this situation. The nonexistence of any steady solution of the Boltzmann equation in this context seems related to the increase of temperature for the evolution problem, a phenomenon that we have established with the help of numerical simulations on the Boltzmann equation and the BGK model.

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。

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