The Numerical Simulation Research For Space Station Cabin Thermal Environment Under The Weightlessness

Spacecraft environment control and life support systems in space station should make the cabin environment with high security and comfort to meet the astronauts' physiological and psychological needs,which can improve ergonomics.Therefore,in order to achieve the transport and exchange of matter and energy,ensure the comfortable of cabin environment,fresh oxygen for the human body needs and contaminant exclusion,we must implement forced ventilation.But there is only forced convection under microgravity,without the natural convection,which resulting in uneven spatial distribution of temperature,concentration and flow characteristics.So we require accurate calculation of flow field and temperature field,and also require design and optimize the airflow in cabin to minimize flow uneven and ensure the safety of astronauts and thermal comfort.Therefore the Space Station ventilation system is very important,and more accurate thermal environment analysis and research on the Space Station is of great significance.With the development of technology,CFD has become a research tools which is equally important with model experiment.Because of the idealized mathematical model and calculation error,it needs to be validated by experiments in practical applications.But the model experiment also have disadvantages,such as high cost,long cycle length,and measurement errors.Therefore,the research for Space Station cabin flow usually contains numerical simulation and model experiment.How to divide the correct grid,choose more accurate turbulence models in the limited computing resources,which is needed to systematic analysis and research.The study focuses on how to proceed more accurately numerical simulation of velocity field and temperature field on microgravity.After the appropriate simplified for real experiment cabin,keeping the true size and airflow,and keeping the heat concentrated in the ground to do analysis.Through the PIV test experiment to get high quality test results,which are compared with the results of numerical simulation.Then,the grid independent solutions is obtained.Comparing Standard k-? and RNG k-? turbulence model can found that Standard k-? turbulence model is more suitable for microgravity.Finally,analyzing the airflow,air supply angle,the number of air outlet to optimize the airflow in the cabin and obtain a more satisfactory cabin thermal environment.