Design Of Subsonic Martian Low Pressure Dust Storm Simulation Wind Tunnel System

To explore the vast universe is an ideal that human beings pursue unremittingly.Columbus found that the American continent changed the world pattern and historical process,Mars is the human"new continent",directly affect the future pattern of the world and the long-term development of our country.The successful landing of the 2021 Mars rover in May marked the beginning of China’s Mars exploration program.However,the Martian environment is extremely harsh,and dust storms on the surface of Mars can cause great damage or even devastating damage to the rover and its payload.Low-pressure storms and dust storms are typical features of the Martian environment,and ground-based simulation is an effective and economical method to solve this extreme environmental problem.However,there is no equipment that can simulate the large-scale Martian low-pressure dust storm environment at home and abroad.Based on the urgent need of the National Deep Space Exploration Project,this paper aims to design a Mars dust storm environment simulation device with an effective test size of 2m×2m,which will provide a powerful experimental and scientific research platform for the follow-up Mars exploration mission of China.Based on the investigation and analysis of the existing advanced wind tunnels at home and abroad,a new scheme of low pressure subsonic reflux wind tunnel based on supersonic ejector is put forward according to the types of wind tunnels,wind speed drive and dust storm generation,the method of using gas as power to spray the dust mixture by nozzle is put forward to generate the dust environment in the cavity.Based on the principle of minimum energy consumption,the wind tunnel body and ejector are designed.The simulation of subsonic Martian low-pressure dust storm environment is divided into two parts,one is the simulation of subsonic environment,the other is the simulation of low-pressure subsonic environment.According to the principles of equivalence,economy and coverage,the physical parameters and parameter range of Mars environment simulation are optimized.The influence of main structure parameters of ejector on ejector efficiency was analyzed by CFD simulation,and the ejector structure was optimized.According to the requirement of simulated wind speed on Mars,the exit position of circumfluence wind tunnel is optimized with the aim of minimum energy consumption.The simulation results show that the wind speed in the test section can reach the target wind speed of 5～180m/s.The state of CO₂in the cave was analyzed to rule out the possibility of gas condensation and liquefaction at low temperature.The force model of sand-dust particles is established,and the movement of sand-dust particles with different diameters is analyzed by combining calculation with simulation,the specific shape,size,installation position and spray direction of the sand-dust nozzle are determined.A Mars dust storm verification experimental system is designed,which is mainly composed of wind tunnel body,vacuum system,sand and dust system,wind speed simulation system,gas source system,measurement and control system,etc.,the wind velocity in low pressure environment can reach 100m/s,and the measurement method and parameters are analyzed,which lays a foundation for the following experiments.