Research On Fluid-solid Coupling Of Parachute In Mars Environment Based On SPH Method

As an important part of deep space exploration,Mars exploration has been widely concerned around the world.Parachute is the important deceleration device of Mars detector,its performance research has become necessary.Large-scale dust storm has certain influence to the parachute work performance which occurs on the Mars frequently.For the problem of negative volume and time consuming in traditional ALE method of the parachute opening process,the Meshless SPH method of fluid-solid coupling simulation of parachute is developed.Firstly,the feasibility experiment of parachute SPH particle fluid-solid coupling method is carried out.A parachute folding model and flow field of SPH particle model are established to simulate the different flow velocity and particle density under the parachute opening process.The dynamic changes of canopy shape,load and projected diameter of parachute opening process are provided.The numerical results are consistent with the results of wind tunnel test,which validate correctness and validity of SPH method in the application of parachute fluid-solid coupling.Secondly,the ALE finite element method and SPH particle method are compared for the Mars environment in parachute steady descent phase.The fluid-solid coupling numerical simulation of the Mars disk-gap-band parachute is developed by two methods.The dynamic changes of canopy shape,equivalent stress,pressure nephogram,canopy load,projected diameter and resistance coefficient are obtained.The comparison and analysis show that the ALE method is more accurate,the SPH method saves time and is more validity.Finally,the SPH particle method combined with the finite element method is applied to the dust storm phenomenon in Mars.Using SPH particles to simulate the Martian dust storm particles and the flow field and parachute are established in finite element model.The fluid-solid coupling simulation of the parachute steady descent stage is carried out with no dust storm,different dust storm velocity,density and distribution area.The dynamic changes of canopy shape,stress,load and deflection angle are obtained.The effect of dust storm strength on parachute performance is analyzed.All those studies would be references for Mars parachute design and development.