沉积粉尘的激波点火

采用瞬态阴影技术及红外光电传感器技术实验研究了沉积玉米粉的激波点火过程，并对此进行了理论分析。实验与理论分析结果表明，激波掠射沉积粉尘床后，粉尘颗粒先上扬到一定高度后才点火，颗粒的点火延迟时间与激波波前马赫数、气相氧气含量等因素有关。另外，沉积粉尘的激波点火延迟时间比相同条件下的悬浮粉尘激波点火延迟时间长。

SHOCK IGNITION OF DUST LAYERS

The experimental studies and theoretical analysas of dust ignition process induced by a shock sweeping a dust layer are presented in this paper. The experiments are conducted in a horizintal rectansular shock tube with the transitent shadow photogrammetry and ultrared photodiode transducer techniques. It is shown that dust particles are first lifted up to a certain altitude and then ignited behind a shock sweeping a dust layer. The greater the preshock Mach number and more the content of oxygen in gas,the shorter the ignition delay time. In addition,the shock ignition delay of a dust layer is longer than that of a suspension because of heat convection to the wall.