Basic Research Of Air Stability Of Limited Room Under Conditions Of Weightlessness And Lunar Gravity

As one of the special moving building space form, the controlling of indoor airquality of the space capsule is very important, and the research has theoretical andpractical meaning. To obtain more reasonable air distribution in the space capsule, theair stability of limited room under two basic gravity conditions (the conditions ofweightlessness and lunar gravity) is studied in this paper, and the influence of indoorair stability on the pollutant transport characteristic is discovered.The influences of different inlet and outlet arrangements of the space capsule onthe flow field and the pollutant transport are analyzed and compared, and athree-dimensional physical model of limited room under the conditions ofweightlessness and lunar gravity is established primarily. The software ofcomputational fluid dynamics (CFD) is used to simulate the pollutant transportcharacteristic of ammonia in three different indoor air stabilities (Case1~Case3). Theresult shows that there is certain internal relation between the air stability of limitedroom and the pollutant transport characteristic. Take into account the pollutanttrapping, the pollutant outlet arrangements of the three-dimensional physical model oflimited room is improved. The influences of three different air stability conditions andtwo different pollutant source positions on the pollutant transport characteristic arecalculated, and the internal relation between air stability of limited room under theconditions of weightlessness and lunar gravity and the pollutant transportcharacteristic is investigated.The results show that the air stability under the condition of weightlessness haslight influence on the pollutant diffusion. g can be treated as a recommendableassessment index. When g is approximately zero, the influence of air stability on thepollutant diffusion is very light. Under the condition of lunar gravity, the pollutantunder the unstable condition diffuses faster in the mainstream direction more slowlyand has an obvious tendency deviating from the mainstream direction and movingclose to the two flanks. The pollutant and the air in the limited room are mixed welland the pollutant diffusion capability is strengthened. The turbulent flow is developedand the limited room is polluted more seriously. The pollutant under the stablecondition diffuses faster in the mainstream direction and arrives at outlet more easily,and diffuses along the mainstream direction strictly. However, the pollutant diffusion capability is weakened and the turbulent flow is restrained, and the limited room ispolluted lightly. In addition, the pollutant transport characteristic under neutralcondition is between the unstable condition and the stable condition.The basic research of air stability of limited room under the conditions ofweightlessness and lunar gravity will provide theoretical basis for the design ofventilation type and pollutant trapping type of the space capsule and the study ofindoor air quality.