Effects Of Different Space Environments On The Extravehicular Spacesuit Performances

The objective of this thesis was to develop a human biological thermal model and a heat andmass transfer model for spacesuits for two different space environments on the Moon and the Mars toset up a foundation for the following study of spacesuits. The matlab programming method wasadopted for modeling computational calculations. The maximum solar radiative heat flux on the Moonwith the metabolic rate of300W, the minimum solar radiative heat flux on the Moon with metabolicrate of150W, the maximum solar radiative heat flux on the Mars with metabolic rate of300W, and theminimum solar radiative heat flux on the Mars with metabolic rate of150W were selected ascalculating conditions.In the human biological thermal model, the human body was divided into15segments, whichwas simplified as the skin layer, the fat layer, the muscle layer and the core layer. Together with thecentral blood pool, a61-node human biological thermal model was established. With this model thephysiological parameters such as sweating rate, chills, blood mass flow and body temperatures werecomputed.The heat and mass transfers between space environment, extravehicular spacesuit, liquid coolinggarment, ventilation garment and the human body were investigated to obtain the liquid temperaturein the liquid cooling garment, the air temperature in ventilation garment and their variations atcorresponding segment under four conditions respectively. The results show that the spaceenvironment temperature and the equivalent thermal conductivity or equivalent radiation rate of theextravehicular spacesuit are the mainly factors to affect the space heat flux to the spacesuit.The cooling liquid mainly took away the heat, and the ventilation gas mainly took away thebreathing exhaust and body moisture. In addition, the temperature of the cooling liquid was low, theoutlet temperature of the ventilation gas would be lower than the inlet temperature of the ventilationgas.At the working pressure of40kPa in the extravehicular spacesuit, the ventilation gas will soonreached the saturation state. Therefore a dehumidification device for the suit is needed.The model could predict the process in which the body reaches its thermal equilibrium state.Therefore it could be used to control the body temperature within a certain range by prediction andadjusting the inlet temperature of the liquid cooling garment.