基于无结构网格的有限体积颗粒相结合的方法求解湍流联合的PDF方程-工程热物理专业论文.docxVIP

摘 摘 要 本文采用一种新的混合算法。对端流的脉动速度一频率 一标量联合PDF输誊撞型左程进行数值求解．采用一种基于 三角形无结构网格的有限体积法，求解质量、动量、能量平均 守恒方程，压力通过理想气体的状态方程求解，所求得的密度 场、速度场、压力场用于PDF方程的计算求解；脉动速度一频 率一标量联合PDF的输运模型方程用拉格朗日Monte-Carlo(颗 粒)方法求解，并为平均守恒方程提供雷诺应力、热通量、能 量源项和7‘．有限体积法和颗粒方法之间的数据交换用一基 于伽辽金算法的线性插值算法来实现．本文对该算法的相容性 进行了深入的讨论，提出相应的修正算法和时间平均方法，以 减小颗粒方法的结果中的统计误差，以确保获得在数值解水平 上的相容．利用该算法，对二维V型槽后的湍流冷态流场和湍 流反应流场进行了数值模拟，最后对计算结果进行了分析和 讨论． 关键词 有限体积法，Monte-Carlo方法，几率密度函数，无 结构网格，湍流反应流，相容性 AbstractIn Abstract In this paper，a new hybrid algorithm for joint fluctuating-velocity-frequency- composition PDF equations of turbulent(reactive)flow is presented．The血ethod combiⅡes of a finite．volume method and a Monte-Carlo(particlel method．The finite- volume method is carried out on triangle unstructured mesh．and i8 used to solve the Reynolds averaged Euler equations．The pressure of the field is calculaged by a state equation of ideal gas．It provides the mean density，mean velocity and pressure for PDF equations．A Lagrangian Monte-Carlo method iS used to SOlye the joint fluctuating-velocity-frequency-composition PDF equations，and provides Reynolds stress，heat flux，甲(and energy SOUrCe term for reactive flow)for the finite·volume scheme．A Galerkin．based linear interpolation technique is employed to exchange the data between the finite-volume method and Monte—Carlo method．The consistent of the hybrid scheme is discussed．Some correct algorithm and time-average technique is introduced to reduce the statistical error．numerical experiments ale carried out Oil the turbulent nonreacting floWS as well as premixed turbulent reactive flows past the binif-bodv in a rectilinear channel．The results ale compared with experimental measurements．LES and k—E model．It shOWS that the result of this scheme iS in good agreement with experimental data． Keywords Finite Volume method，Monte-Carlo method，PDF function，un— structured mesh，turbulent reactive flows，consistent ◆ II 第1章引 第1章引 言 1．1湍流燃烧数值模拟的方法 湍流广泛存在于自然界中，工程实际中涉及的燃烧过