爆轰波在弯管内传播过程数值分析

应用基元反应模型和频散可控耗散格式(DCD)对氢氧爆轰波在弯管内的传播过程进行了数值模拟.计算中氢氧混合物化学反应采用了8种组分20个反应方程式.在处理化学反应引起的刚性问题时采用了时间算子分裂的方法.计算结果表明,在弯管小曲率半径壁面附近,由于膨胀稀疏作用,爆轰波强度减弱,在局部出现前导激波与放热反应区的解藕以及二次起爆现象;在弯管大曲率半径壁面上爆轰波在马赫反射和正规反射之间相互转变,使爆轰波加强.弯管内的爆轰现象与弯管曲率半径有关.

Numerical Simulation of Gaseous Detonation Wave Propagation Through Bends with a Detailed Chemical Reaction Model

The chemically reacting flow-field of a detonation wave in a bend is simulated by CFD method. The dispersion-controlled dissipative scheme(DCD) is adopted to solve two-dimensional Euler equations implemented with detailed chemical reaction kinetics of hydrogen-oxygen-argon mixture. The fractional step method is applied to treat the stiff problem arising from computation of chemical reaction flow. From the numerical results it is observed that as the curvature of the bend changes,different detonation phenomena occurred along the wall of the bended pipe.If detonation wave propagating through bend with little curvature,the affection of the expansion wave is then stronger to induce the decouple process of the reaction zone and the leading shock.Re-setup of detonation can be completed when the overdriven detonation from another wall reignites the gas mixture in the decoupled zone,and then high overpressure impacts on the bend wall.