Transient thermal and pressurization performance of LO_2 tank during helium pressurization combined with outside aerodynamic heating

摘要

A computational fluid dynamic (CFD) model, which can simultaneously account for the heat exchanges inside the tank and outside aerodynamic heating, is constructed to investigate the transient thermal and pressurization performance of cryogenic tank during discharge. Besides the fluid and tank wall regions, the foam region is also considered as the computational domain. Reference enthalpy method is used to account for the outside aerodynamic heating effect. The predictive ability of the CFD model is evaluated on the basis of the comparisons between its results and experimental data and a good agreement is obtained. Then the model is used to predict a pressurized discharge event, and the thermal and pressurization behaviors are obtained and analyzed. The results show that outside aerodynamic heating cannot penetrate the foam layer to facilitate the pressurization performance. Conversely, a certain proportion of energy might be transferred from heated tank wall to foam layer, which exert a negative effect on the pressurization behaviors. The aerodynamic heating effect may not be accounted for in the CFD simulation of a foam-insulated tank, if the thermal performance at outer surface of the tank is not particularly concerned. Generally, this paper supplies an effective way to predict pressurization performance and expresses valid results of the thermal performance inside and outside the cryogenic tank during discharge. It is also stated that the CFD model has a better accuracy in predicting pressurization characteristics.