火灾试验中复合推进剂热辐射通量的测量

Measurement of heat flux for the composite propellants in the external fire test

为了验证热辐射通量理论计算方法对推进剂的适用性,采用热辐射计测试了三种推进剂在外部火烧试验中的热辐射通量最大值和平均值,并根据样品燃烧时间计算了样品的热辐射通量。三种推进剂的热辐射通量的测量平均值为2.87kW/m2,2.65kW/m2和3.44kW/m2,理论计算值为4.06kW/m2,7.62kW/m2和3.67kW/m2。结果表明:当样品燃烧时间大于5s时,热辐射通量的测试平均值与理论计算值基本一致;当燃烧时间小于5s时,由于理论计算公式中设定的燃烧热转变为辐射热的比例(0.33)大于实际转化率,导致热辐射通量的理论计算值偏大,因此建议用热辐射计测量样品的热辐射通量。

External fire tests were performed to determine the applicability of heat flux estimation method to propellants.The heat fluxes of three propellants were measured by a radiometer and calculated through the estimation method respectively.The average values of measured heat fluxes were 2.87kW/m2,2.65kW/m2 and 3.44kW/m2,while the corresponding calculated values were 4.06kW/m2,7.62kW/m2 and 3.67kW/m2.The results show that,as the burning time is greater than 5s,the calculated heat flux is in accordance with the measured value;and as the burning time is less than or equal to 5s,measuring the heat flux by radiometer is proposed,because the ratio of radiant heat to combustion heat used in estimation method（0.33） is greater than the actual ratio,and it will lead an abnormal calculated value.