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内燃机整个工作循环中 ,其缸内流体始终进行着极其复杂而又强烈瞬变的湍流运动 ,正确地模拟和分析内燃机的燃烧和排放 ,离不开对缸内湍流运动的正确描述和模拟。把一个非线性三方程k -ε -A2 .湍流模型修正后应用于内燃机缸内湍流计算 ,此模型采用了雷诺应力张量和应变张量的三阶相关关系 ,表示雷诺应力张量和应变张量相关关系方程式中出现的雷诺应力第二不变量A2 是通过求解其输运方程得到的 ,计算采用任意拉格朗日欧拉法。用此模型对几种内燃机内的缸内流场进行计算 ,给出了用非线性三方程模型计算得到的结果 ,并与标准的k -ε模型算得的结果和实验结果进行了比较 ,结果表明 ,此模型适合于计算内燃机缸内湍流流动
In the whole working cycle of an internal combustion engine, its in-cylinder fluid always undergoes extremely complex and intense transient turbulent motion. Correctly simulating and analyzing the combustion and emission of an internal combustion engine can not be separated from the correct description and simulation of the in-cylinder turbulent motion. A nonlinear three-equation k -ε-A2 turbulence model is applied to the internal turbulence calculation of internal combustion engine. This model uses the third-order correlation between Reynolds stress tensor and strain tensor to represent the Reynolds stress tensor and strain tensor Reynolds stress in the correlation equation The second invariant A2 is obtained by solving its transport equation, calculated using any Lagrange Euler method. Using this model to calculate the internal flow field in several kinds of internal combustion engines, the results calculated by the nonlinear three-equation model are given and compared with the results calculated by the standard k-ε model. The results show that , This model is suitable for calculating the turbulent flow in the cylinder of an internal combustion engine