贫氧燃气流过有机玻璃圆管耦合传热数值模拟

为了掌握燃气流过有机玻璃圆管的降温情况,以设计出可实现所要求的燃气出口温度的降温装置,对燃气流过有机玻璃圆管内,管内壁径向热降解的变化过程进行数值模拟,将推导出的PMMA管内壁面平均升温速率与特征降解温度关系式结合动网格和质量掺混技术求解该问题,得到固定与不固定燃气入口面积情况下管内壁面轮廓的时间形及流场参数时间分布。计算结果表明,固定燃气入口面积较不固定燃气入口面积对燃气的降温量大;固定燃气入口面积时,入口处管内壁面的径向降解程度最小,距入口沿轴向一段距离处管内壁面的径向降解程度最大;不固定燃气入口面积时,入口处管内壁面径向降解程度最大,出口处管内壁面的径向降解程度最小。

Numerical simulation on coupling heat-transfer of low oxygen gas flowing through PMMA tube

In order to know cooling situation of gas flowing through PMMA and design the cooling device which meets required gas outlet temperature,the change of thermal degradation process along radial direction of tube inwall was numerically simulated when gas flowing through PMMA.Combining moving mesh and mass mix technique,the deduced relation expression between average warming-up rate and characteristic degradation temperature of PMMA tube inwall was used for solving the above problem.The curves of tube inwall contour vs time and flow field parameters vs time under fixed and unfixed gas inlet area conditions were obtained.The calculation results show that temperature drop under fixed gas inlet area is more than that under unfixed gas inlet area.For fixed gas inlet area,radial degradation degree is the lowest in the inlet of tube inwall,and biggest at a distance from inlet of tube inwall.For unfixed gas inlet area,radial degradation degree is the biggest in the inlet of tube inwall,but lowest in the outlet of tube inwall.