【摘要】 以热机理为基础 ,建立了激光点火过程的二维非稳态热传导模型 ,模型中考虑了激光光能分布、反应物浓度、对流换热和热辐射等因素对点火过程的影响。采用交替方向隐式算法求解偏微分方程。并以Mg/NaNO3药剂为研究对象 ,通过计算分析了激光脉宽、光束半径、材料热传导系数、浓度吸收等因素对点火的影响。结果表明 :入射功率、脉宽、光束半径是影响含能材料点火特性的主要因素 ;点火时间较短时 ,热传导系数的变化对点火影响较小 ,吸收系数的变化对点火影响较大更多还原

【Abstract】 A transient, two-dimensional heat conduction model about laser ignition based on thermal mechanism was developed in this paper. Influences of the laser energy distribution, reactant concentration, heat convection and radiation factors are considered in the model. Its partial derivative equation is solved by alternating direction implicit algorithm. Influences of some factors, such as laser pulse width, beam radius, thermal conduction and depth absorption coefficient, on the ignition of Mg/NaNO 3 were analysed. Results show that the incidence power, the laser pulse width and the beam radius are main factors effective for ignition characteristics of energetic material. In shorter ignition time, the variance in thermal conduction coefficient has less influence on the ignition process and the varienc of the absoption coefficiet has more influence on it.更多还原