On solving the compressible Navier-Stokes equations for unsteady flows at very low Mach numbers
On solving the compressible Navier-Stokes equations for unsteady flows at very low Mach numbers
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DOI：
10.2514/6.1993-3368
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发表时间：
1993-07
期刊：
影响因子：
--
通讯作者：
R. Pletcher;K. Chen
中科院分区：
文献类型：
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作者：
R. Pletcher;K. Chen
研究了两种低速非定常流场，即脉冲启动驱动空腔和管道启动驱动流，在原始变量下求解可压缩Navier-Stokes方程的预条件、耦合、强隐式有限差分格式的性质。对于剪切驱动的空腔流动，计算工作量几乎与马赫数无关，特别是在考虑范围的低端。这种马赫数独立性也被观察到稳定的管道流动计算；然而，非定常计算得出了截然不同的结论。在压力驱动管道启动问题中，在相当低的马赫数下，流体的可压缩性开始显著影响流动发展的物理特性。当马赫数设置在非常低的值时，观察到本方案产生完全不可压缩流动的预期特性。观察到与文献中可用的不可压缩结果良好的一致性。
The properties of a preconditioned, coupled, strongly implicit finite difference scheme for solving the compressible Navier-Stokes equations in primitive variables are investigated for two unsteady flows at low speeds, namely the impulsively started driven cavity and the startup of pipe flow. For the shear-driven cavity flow, the computational effort was observed to be nearly independent of Mach number, especially at the low end of the range considered. This Mach number independence was also observed for steady pipe flow calculations; however, rather different conclusions were drawn for the unsteady calculations. In the pressure-driven pipe startup problem, the compressibility of the fluid began to significantly influence the physics of the flow development at quite low Mach numbers. The present scheme was observed to produce the expected characteristics of completely incompressible flow when the Mach number was set at very low values. Good agreement with incompressible results available in the literature was observed.