飞机燃油箱地面冷却惰化数值仿真

通过 COMSOL软件对飞机燃油箱地面冷却惰化进行了 3D仿真,得到了燃油温度、气相空间温度、燃油蒸汽体积分数随时间变化的情况；研究了抽气流量、蒸发温度、内热源功率、外界空气流速对冷却惰化的影响。结果表明:内热源功率过大时,燃油蒸汽体积分数高于可燃体积分数下限,将不能惰化；增大抽气流量以及降低蒸发温度,可以更快地降低气相空间温度,惰化效果更好；外界空气流速越大,气动加热热量越大,油箱气相空间温度越高,但外界空气流速较大时,系统仍能惰化。

3D Simulation of Ground Cooling Inerting of Aircraft Fuel Tanks

3D simulation of ground cooling inerting of aircraft fuel tank is carried out by COMSOL software, the fuel tempera.ture, gas-phase temperature and the volume fraction of fuel vapor with time are obtained, the influences of extraction flowrate, evaporation temperature, internal heat source power and external air velocity on cooling inerting are studied. The re.sults show that the volume fraction of fuel vapor is higher than the lower flammable limit when the power of the internal heatsource is too large, and the fuel vapor cannot be inerted; the increasing of the pumping flow rate and decreasing of the evapo.ration temperature can reduce the gas-phase temperature faster, and the inerting effect is better; the higher the external airvelocity is, the greater the pneumatic heating heat is, the higher the tank gas phase temperature is, and inerting of systemcan still be realized when the external air velocity is larger.