吸气式脉冲爆震发动机壁温试验

Experiment on wall temperature of an air-breathing pulse detonation engine

关键词:  吸气式脉冲爆震发动机⁺  频率  热成像仪  壁温

Key words:  Air-breathing pulse detonation engine⁺  Frequency  Thermal image camera  Wall temperature

摘要:

为了探索各频率下管壁温度随时间的变化趋势及爆震管外壁面的温度分布规律,对爆震室内径68mm,长2 000mm,以汽油为燃料、空气为氧化剂的吸气式脉冲爆震发动机进行试验,用热成像仪对稳定工作在10Hz,20Hz,40Hz下的管壁温度进行了监测。结果表明:同一频率下随时间的增加壁面温度增加速度减小；热平衡时壁面温度随频率的增加而增长,10Hz,20Hz,40Hz热平衡时外壁面最高温度分别在726℃,1011.5℃,1159.5℃以上；热平衡前管壁温度的增长速度随频率的增加而增加,管壁温度的增长速度跟频率约成正比；爆震室上沿着压缩波叠加至形成爆震的方向,温度在外壁面上递增分布,在爆震形成区温度最高,从爆震形成区到发动机出口处,温度在外壁面上逐渐降低；各频率下最高温度区位置基本不变,距点火位置1 350mm左右；同一轴向位置上的外壁面温度随频率的增加而增加,温度的增长幅度随频率的增加而减小。

Abstract:

To explore the trends of wall temperature variation with time and detonation frequency as well as wall temperature distribution along the tube outer wall, experimental study on wall temperature of an air-breathing pulse detonation engine was performed. This is a valveless air breathing pulse detonation engine with 68mm in diameter and 2000mm in length. The experiment was conducted with gasoline /air mixture at frequency of 10Hz,20Hz,40Hz,respectively. The wall temperature was measured by a thermal image camera. The results indicate that:(1) the increasing rate of outer wall temperature decreases as time increasing on the same frequency; (2) at heat balance point, outer wall temperature is higher with higher frequency；at frequency of 10Hz,20Hz,40Hz, outer wall temperatures are over 726℃,1011.5℃,1159.5℃, respectively at the heat balance point; (3) before heat balance, increasing rare of wall temperature increases as frequency increasing；increasing rate of wall temperature is proportional to frequency approximately; (4) along the direction of forming detonation, outer wall temperature increases by degrees; at the detonation point temperature is highest; from detonation point to engine exit, outer wall temperature decreases by degrees; (5) on each frequency, the highest temperature area is the same, about 1 350mm from the ignition location; (6) at the same axial location, outer wall temperature increases as frequency increasing.The increasing amplitude of the temperature decreases as frequency increasing. 