装药尺寸对高氯酸铵/端羟基聚丁二烯底排药烤燃特性的影响

为研究装药尺寸对高氯酸铵（AP）/端羟基聚丁二烯（HTPB）底排药烤燃响应特性的影响，基于AP/HTPB两步分解反应机理，建立底排药柱烤燃计算模型。分别选取装药长度为72 mm 和内孔直径为 43 ~53 mm、内孔直径为43 mm和装药长度为72~90 mm的圆环柱状底排药，在1.0~ 10.0 K/min加热速率下对某底排装置的烤燃特性进行数值模拟。结果表明：在相同加热速率和装药长度条件下，随着装药内孔直径的增大，底排药的烤燃响应时间缩短；当装药内孔直径不变，装药长度增加至90 mm，底排药的烤燃响应时间明显缩短；装药尺寸的变化对底排药的烤燃响应位置的影响较小；在1.0~2.5 K/min中速烤燃条件下，随着内孔直径和装药长度分别增大，底排药的烤燃响应温度逐渐增大；在5.0~10.0 K/min快速烤燃条件下，装药尺寸的变化对底排药的烤燃响应温度的影响较小。

Effect of Charge Size on Cook-off Characteristics of AP/HTPB Base Bleed Propellant

To investigate the effect of charge size on the cook-off characteristics of ammonium perchlorate (AP)/ hydroxyl-terminated polybutadiene (HTPB) base bleed propellant,a cook-off model of base bleed propellant grain is established based on the two-step decomposition reaction mechanism of AP/HT-PB.The AP/HTPB propellant is 72 mm in charge length and 43-53 mm in grain diameter,as well as 43 mm in grain diameter and 72-90 mm in charge length.The cook-off characteristics of AP/HTPB base bleed propellant are simulated at the heating rates from 1.0 K/min to 10.0 K/min.The results show that the cook-off time is shortened with the increase in the grain diameter of charge.As the charge length of AP/HTPB propellant with same grain diameter is added to 90 mm,the cook-off time is shortened remarkably.The charge size has little influence on ignition position.At the medium heating rates of 1.0-2.5 K/min,the ignition temperature rises with the increase in grain diameter and charge length.At the fast heating rates of 5.0-10.0 K/min,the charge has a less effect on the ignition temperature of AP/HTPB propellant.