Large eddy simulation of deflagration to detonation transition

Abstract

Deflagration to detonation transition (DDT) is a very important research project for both national defense and energy industry. It is the process where a subsonic deflagration transits into a supersonic detonation, which generates shock waves. In the past years, the simulations of DDT were limited in a small domain, usually sev- eral cubic centimeters. If we want to simulate it in a larger space without improving the numerical method, we need to use the more powerful computer. When the computing resources are limited, we must improve the numerical method to achieve the big-domain simulating. There are two technical paths, one is the adaptive mesh refinement and the other is the large eddy simulation. Both of them are difficult to realize. In this project, we focus on the usage of the LES method for simulating DDT. The main challenge in this work is to develop a reliable model. In this research, a new approach for LES modelling was developed. It is a fully compressible variant of the artificial thickened flame model, which adopts the opt- ing functions on the reference flame thickness. This method ensures that the flame is not over-thickened in deflagration or detonation. To control the options on the flame thickness, a detonation sensor is utilized during the computing.