非均匀热气体红外辐射特性计算与仿真

非均匀热气体由于内部空间点的温度、密度、组分及压力各不相同,其红外辐射特性的计算十分困难。为了计算非均匀热气体的红外辐射特性,首先从分析非均匀热气体特点和均匀热气体的谱带模型出发,以原子分子辐射理论为基础,结合谱线的碰撞展宽效应和多普勒展宽效应,利用单谱带模型Curtis-Godson(C-G)近似法对非均匀热气体谱带模型所用到的谱带模型参数进行了计算,提出一种计算非均匀热气体红外辐射特性的方法。最后,应用此方法计算了某单发动机喷气式飞机在非加力状态下尾焰3～5μm的红外辐射强度,计算结果与文献中给出的实际测量的尾焰红外辐射数据能较好地吻合,计算仿真结果验证了该方法的正确性。

Dynamic Analysis for the Global Performance of An SPM-Feeder-Cage System Under Waves and Currents

In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodynamics coefficients of the vessel are calculated by using a 3D diffraction/radiation panel program. First- and second-order wave forces are included in the calculations. Morison equation is used to compute the drag force on line elements representing the net. Drag coefficients are determined at every time step in the simulation considering the relative normal velocity between the structural elements and the fluid flow. The dynamic response of the coupled system is analyzed for various environments and net materials. The results of the study show the effects of solidity ratio of the net and vertical positions of the cage on the overall dynamic response of the system, confirming the viability of this type of configuration for future development of offshore aquaculture in deep waters.

月球探测器发动机羽流辐射热流计算

火箭发动机羽流的辐射的计算需要求解气体介质的辐射传递方程(RTE).计算模型中基于单线组(SLG)模型考虑气体组分的光谱特性,并采用离散传递法(DTM)求解RTE,对波长积分得到辐射热流密度.通过对圆柱高温CO2气团辐射热流计算来验证计算程序,然后在流场计算的基础上,计算了月球探测器主发动机和姿控发动机羽流对各部位和仪器的辐射热流密度,根据对不同工况计算结果的分析为探测器的设计提供参考.