Ground Based Thermal Scale Modeling Of A Space Station Cabin And Numerical Analysis

The objective of this study is to find a method to simulate the heat transfer of the space station cabin on the ground and to improve the ventilation of the space station cabin under the micro-gravity environment. Based on theoretical analysis, a thermal scale modeling technique where the natural convection can be suppressed is applied to the ground simulation of ventilation in a space station. If the model size is properly reduced, the effect of natural convection can be eliminated. By means of numerical analysis, the critical non-dimensional parameter which indicates the negligible effect of natural convection in the mixed convection is Gr/Re~n(n=1.6 - 2.0). For uniform heat flux condition, a so-called temperature-material preservation technique has been advanced which was widely believed before that the temperature and material can't be preserved simultaneously if the thermal scale ratio does not equal to unity. Analyses show the reason that the temperature and material can't be preserved simultaneously for the model lies in that the radiation heat flux doesn't change with the scale ratio. Through the technique of wall heat flux compensation and modification, material, temperature and humidity can be preserved simultaneously. That is to say, when the model size is properly reduced the natural convection can be dramatically suppressed, so that the heat and mass transfer of the ground based model can represent that in the space cabin. Also, the similarity between the model and the prototype in temperature, humidity and flow field of the space station can be obtained on the ground with this preservation technique.Study of ventilation in a space station cabin has been conducted by means of three-dimensional convection-radiation heat and mass transfer modeling. The possible ventilation configuration has been proposed to meet the requirement of the comfort and the homogeneity of temperature, humidity and velocity.