论文部分内容阅读
为了准确、高效地计算火箭尾焰的红外辐射特性,提出了一种确定火箭尾焰区域的方法。作为基础工作,分别使用FLUENT和有限体积法(FVM)完成尾焰流场和红外辐射的计算。分析了可能用来区分尾焰和周围大气的变量,如温度和组分含量等,并选择CO的质量分数作为阈值变量。即,在选定阈值后,计算尾焰红外辐射时仅考虑CO质量分数大于阈值的区域,忽略小于阈值其区域对整体辐射的影响。分别研究了尾焰尺寸、计算时间和辐射强度随阈值的变化规律,结果表明,随着阈值的减小,尾焰尺寸和计算时间迅速单调增加,尾焰的红外辐射强度不断波动,且波动幅度逐渐变小,最终趋于平稳。另外,算例表明,选择CO质量分数为0.000 5作为阈值可以确定一个比较合理的尾焰计算区域。
In order to accurately and efficiently calculate the infrared radiation characteristics of the rocket tail flame, a method of determining the rocket tail flame region is proposed. As a basic work, FLUENT and the finite volume method (FVM) were used to complete the calculation of the flame flow field and infrared radiation. The variables that may be used to distinguish the tail flame from the surrounding atmosphere, such as temperature and composition, are analyzed and the mass fraction of CO is chosen as the threshold variable. That is, after the threshold is selected, only the region where the CO mass fraction is greater than the threshold is considered when calculating the endfire infrared radiation, and the effect of the region thereof on the whole radiation is neglected below the threshold. The results show that as the threshold decreases, the tail flame size and calculation time increase monotonically, and the intensity of the infrared radiation of the tail flame fluctuates continuously. The variation of the amplitude of the tail flame, Gradually smaller, eventually tends to be stable. In addition, the example shows that selecting a CO mass fraction of 0.0005 as the threshold can determine a more reasonable tail flame calculation region.