爆炸近区流场的数值模拟方法研究

提出了一种用于模拟爆炸近区炸药、爆轰产物、空气等相互作用流场的数值方法。在欧拉型方法中引入了一种炸药、爆轰产物、空气3种组分的混合模型，该模型中炸药及爆轰产物采用Jones-Wilkins-Lee(JWL)状态方程，空气采用理想气体状态方程，在固相与气相间满足等压假设和体积可加性，气相组分间满足等温假设和分压定理。该模型无需迭代求解，计算效率较高。化学反应率采用“点火—生长”模型，采用AUSM₊-up格式计算通量。计算了空气中球形TNT装药的爆炸问题，可以清晰地看到爆轰波在流体界面上发生的透射、反射等一系列复杂作用过程。计算得到的超压峰值在直至距药球表面5 cm的位置都与实验结果符合良好，冲击波到达时间、超压比冲量等与现有实验结果也符合较好，验证了本方法的有效性和准确度。

Research on Numerical Simulation Method of Near-field Flows in Air Blast

A new method of simulating the explosion flowfield due to the interaction of explosives,detonation products and air was proposed.A mixing model of explosives,detonation products and air was introduced in Eulerian method.In this model,Jones-Wilkins-Lee(JWL) state equation was used for the explosives and products,while a prefect gas state equation was used for air;an equilibrium pressure assumption was made between explosives and products,while an equilibrium temperature assumption was made between products and air;no iteration is required in this model,so a high efficiency is achieved.An ignition and growth model was used to calculate the chemical reactivity,and AUSM+-up scheme was used to calculate the convection flux.The explosion of spherical TNT explosives in air was calculated,and a series of complex interactions,such as transmission and reflection,between detonation wave and fluid interface were observed.The calculated peak over-pressure accords well with experimental results even at 5 cm from the explosive surface.The arriving time of blast wave and the specific impulse of overpressure also accord well with the existing experimental results,which validates the availability and accuracy of the method.