A Study on Coherent Structures of Turbulence in Reacting Jet

Large eddy simulation was performed for a turbulent jet of diluted hydrogen. Treated were the case where hydrogen reacts with surrounded oxygen and the case where only mixing occurs without reaction. Coherent structures of turbulence in these cases were investigated. In reacting case, temperature rise causes significant drop of flow density, and, thus, velocity is two times as higher as the counterpart at the same position of non-reacting case. In spite of dramatic change in order of velocity magnitude, there is close similarity between two-point correlation of reacting case and that of non-reacting case. In two cases, coherent structure inclined against jet central axis was suggested through distribution of two point correlation and PDF of vorticity fluctuation vector.