可压缩流大涡模拟耦合概率密度函数方法中的滤波压力模型

亚格子组分-温度关联项显著影响反应流大涡模拟精度。利用概率密度函数方法中概率等效的特点,发展一种新的滤波压力模型,可以良好封闭亚格子组分-温度关联项。介绍概率密度函数及其耦合求解方法,在已有模型基础上推导建立新的滤波压力模型,并在三维超声速氢气/空气时间发展反应混合层中对不同的滤波压力模型进行数值测试。结果表明,与传统的滤波压力模型相比,新的滤波压力模型可以明显改善反应混合层的模拟准确度。特别地,基于新的滤波压力模型,大涡模拟耦合概率密度函数方法可以较好地模拟链式反应中间微小组分如超氧化氢基等,有望更有效地再现自点火等复杂现象。

Filtered pressure model in large eddy simulation coupled probability density function method for compressible flows

The subgrid species-temperature correlation term significantly affects the accuracy of large eddy simulation of reactive flows. A new filtered pressure model was developed by using the basic characteristics of probability equivalence in the probability density function method, which can well close the subgrid species-temperature correlation term. The probability density function and its coupling solution method were introduced. Then, a new filtered pressure model was derived based on previous models. Numerical tests of different filtered pressure models were carried out in a three-dimensional supersonic hydrogen/air temporally evolving reactive mixing layer. The results show that, compared with the traditional filtered pressure model, the new filtered pressure model can significantly improve the simulation accuracy of the reaction mixing layer. In particular, based on the new filtered pressure model, the large eddy simulation coupled probability density function method can better simulate minor species in the chain reaction such as hydrogen peroxide, which is expected to more effectively reproduce complex combustion phenomena such as self ignition.