弯曲方管内爆燃向爆震转变特性

Deflagration to detonation transition characteristic in U-bend square tube

为缩短爆震管轴向尺寸,采用曲管爆震管替代直管爆震管.基于弯曲方管实验器,进行了二维数值仿真计算,研究了点火位置、点火能量及弯曲段曲率半径对爆震波形成及传播的影响规律.数值模拟结果表明:爆燃向爆震转变(DDT)时间随弯曲段曲率半径增大而减小,DDT距离在弯曲段曲率半径最大时达到最小值;点火能量越大,爆震管内激波强度越大,DDT时间越小;在距离爆震管进口300mm处点火时,爆震管内爆震波压力峰值最大,DDT时间最短.

To shorten the axial length of detonation tube, a practicable way was used by replacing straight detonation tube with a curve one. A series of two-dimensional numerical simulations were performed in U-bend square tubes, and the effect laws of ignition position, ignition energy, inner radius of bend-section on formation and diffusion of detonation wave were studied. The simulation results show that the deflagration to detonation transition （DDT） time reduces with the increase of inner radius of bend-section; when the inner radius of bend-section is the maximum, the DDT distance is the shortest; the increasing ignition energy means the increasing shock wave strength in detonation tube and the decreasing DDT time; when the ignition position is set at 300 mm after the inlet of the detonation tube, the peak pressure of detonation wave is the highest, and the DDT time is the shortest.