A new method of simulating the explosion flow-field 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 over-pressure also accord well with the existing experimental results, which validates the availability and accuracy of the method.%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.
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