定容燃烧弹内流体介质的初始温度场分布

Initial temperature field distribution of fluid medium in constant volume combustion bomb

基于Fluent软件对加热状态下圆柱形定容燃烧弹内的初始温度场进行模拟,并与实验值进行对比,结果验证了模拟结果的准确性.模拟结果表明,在加热状态下,弹内流体介质温度呈现沿重力方向先下降后上升的变化趋势,且随着弹内温度升高,弹内流体介质温度场不均匀性增大.加热带电压分别为90 V、120 V和150 V时,该定容燃烧弹初始温度认定的误差最大可达25 K、40 K和60 K,流体介质在沿重力方向上的最大温差分别达14 K、23 K和35 K,弹内流体呈现沿两侧玻璃内表面向下流动至容弹底部中间区域交汇的趋势.同时,模拟结果也表明,在定容弹外壁均布热源以及对玻璃视窗进行加热有利于改善定容弹内流体介质温度场的不均匀性.

Based on the Fluent software,the initial temperature field distribution in cylindrical constant volume combustion bomb was simulated and compared with the experimental values to validate the numerical results. Results show that the temperature distribution of fluid in chamber exhibits a significant gradient that decreasing firstly and then rising along the gravity direction. With the increase of the overall temperature in the chamber,the non-uniformity of the temperature field gradually increases as well. When the heating band voltages are 90 V,120 V and 150 V respectively,the maximum error of the identified initial temperature in chamber are 25 K,40 K and 60 K respectively, and the maximum temperature difference of the fluid medium along the gravity direction reaches 14 K,23 K and 35 K respectively. The fluid in the chamber flows along the inner surface of the glass windows and converges at intermediate bottom of the chamber. In addition,the numerical simulation results show that it is advantageous to improve the non-uniformity of the temperature field by uniformly distributed heater attached to the outside surface of the constant volume bomb or heating the optical quartz glass windows.