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在干扰剪切流(Interacting Shear Flow,ISF)理论的基础上,提出ISF稳定性理论并把它用于改进高雷诺(Re)数流动计算方法。(1)高Re数内外绕流的RANS计算及工业标准PNS计算中,流动转捩的预测均基于经典边界层理论;然而转捩并非总是最早发生在边界层中,例如发生在壁面小突起、小凹坑、小窄缝等局部粘性/无粘强干扰区,这些强干扰区可能位于边界层内,但边界层理论并不适用于它们,又如转捩发生在分离点邻域强干扰区等。(2)ISF理论表明:高Re数内外绕流为一复杂ISF,转捩总是最早发生在该ISF的层流区中。(3)ISF稳定性理论表明:作者提出的干扰剪切扰动流(Interacting Shear Perturbed Flow,ISPF)方程组可以计算ISF层流中非湍流扰动运动演化并预测转捩;ISF方程组和ISPF方程组分别与PNS和抛物化稳定性方程(PSE)为同类方程组,PSE分析计算边界层稳定性的众多成功实践,说明用ISPF(即PSE)方程组计算ISF层流扰动流并预测转捩完全可行。(4)RANS和PNS方法经ISF稳定性理论改进后,在转捩前用ISF方程组(即PNS)计算ISF层流基本流,用ISPF方程组(即PSE)计算ISF层流扰动流并预测转捩位置;转捩后RANS方法计算RANS或RANS/LES,PNS方法计算干扰剪切湍流(ISTF)方程组即抛物化RANS(PRANS)方程组。改进后的两方法,理论合理正确,方程体系完备、自洽,ISF方程组只能用ISPF方程组相配对,因此是高Re数内外绕流计算的理想且可持续发展的两种方法。
Based on the theory of Interacting Shear Flow (ISF), the ISF stability theory is proposed and used to improve the calculation of high Reynolds number flow. (1) The RANS calculation of high and low Reynolds numbers flow and the prediction of flow transition in industry-standard PNS calculation are all based on the classical boundary layer theory; however, the transition does not always occur in the boundary layer at the earliest, for example, , Small pits, small narrow slits and other local viscous / non-tacky strong interference areas, these strong interference areas may be located in the boundary layer, but the boundary layer theory does not apply to them, and if the transition occurred in the neighborhood of strong points of interference Area and so on. (2) The theory of ISF shows that the flow with high Re number is a complex ISF, and the transition is always occurred in the laminar flow region of ISF. (3) The theory of ISF stability shows that: the Interacting Shear Perturbed Flow (ISPF) equations proposed by the authors can calculate the evolution of non-turbulent disturbances in ISF laminar flow and predict the transition; ISF equations and ISPF equations Respectively, and PNS and parabolic stability equation (PSE) for the same equation, PSE analysis and calculation of the stability of the boundary layer of the many successful practices, using ISPF (ie PSE) equations to calculate ISF laminar flow perturbation flow and predict the transition is entirely feasible . (4) After improved by ISF stability theory, the RANS and PNS methods calculate the ISF laminar flow with ISF equations (PNS) and the ISPF equations (ie PSE) RANS method is used to calculate RANS or RANS / LES, PNS method to calculate interference shear turbulence (ISTF) equations that parabolic RANS (PRANS) equations. The improved two methods, the theory is reasonable and correct, the equation system is complete and self-consistent. The ISF equations can only be matched by the ISPF equations. Therefore, the two methods are ideal and sustainable.