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.