Parallel Simulations Of Aerodynamics And Aeroacoustics Of Airliner's High Lift Device

After unremitting efforts of several generations,our civil aviation industry is developing rapidly,and developing domestic airliners is one of our national major development projects.The high lift device is an important part of the airliner,and it is composed of a set of movable panels,which can improve the flow state of the wing and increase the lift during take-off and landing.However,the complex geometry of the high lift device will cause very complex air flow phenomena,which has always been a difficult and important point in computational aerodynamics.In addition,the high lift device will have a huge noise impact on the ground during landing.In order to improve the market competitiveness and ensure the sustainable development of our airliner,it is of great significance to simulate the aerodynamic and aeroacoustic state of the high lift device and the whole aircraft with CFD,count and analysis relevant aerodynamic parameters,research the noise generation mechanism,put forward effective noise reduction measures,reduce aircraft aerodynamic noise level.The computational fluid dynamics software CFD++,which was developed by Metacomp Technologies,is very good at solving aerodynamics problems.In this paper,CFD++ is used to simulate the aerodynamics of tandem double cylinders,30P30 N lift device,a certain type of wing body assembly and Tu204 aircraft with a variety of turbulence models on the high performance computing cluster of Shanghai University.And then flow field nephograms,streamline diagrams,surface pressure coefficient,lift coefficient and drag coefficient under various aerodynamic conditions are output,which are compared with wind tunnel test results and CFD calculation results in literatures.The comparison shows that the simulation results are in good agreement with the experimental results,and some of them are better than the simulation results of other CFD methods.All kinds of complex aerodynamic states are restored with high precision,which lays a foundation for the subsequent aerodynamic noise research and the noise reduction design of the high lift device.Based on the above,the aerodynamic noise of the high lift device is simulated.Firstly,the cubic k-eps two equation model is used to calculate the noise input,and then the nonlinear noise solver is used to simulate the noise source.In the calculation process,the pressure probe is used to capture the near-field noise information,and the pre-set envelope surface is used to record the historical information of the pressure fluctuation.After that,the far-field noise information is calculated with the FW-H equation.In this paper,the near-field and far-field aerodynamic noise of 30P30 N lift device during landing is restored,and vortex structure cloud diagrams,near-field point PSD diagrams and far-field point PSD diagrams are output,which are consistent with wind tunnel test results.By analyzing the mechanism of aerodynamic noise,the noise reduction design of the high lift device is carried out,and good noise reduction effect is achieved.The noise reduction mechanism is analyzed by using the prediction formula of the slat cavity's discrete noise peak frequency.Then,the far-field noise of Tu204 aircraft is simulated preliminarily,and the credible calculation results are obtained,which highlights the necessity of the aircraft noise reduction.Finally,the parallel performance of the high-performance computing is evaluated and optimized,and good parallel efficiency and speedup ratio are obtained.The parallel computing module of CFD++ has good scalability,and can maintain high parallel efficiency for CFD problems with different computing scale and different simulation methods.It can be seen that the high performance computing technology can greatly improve the computational efficiency of the time-consuming aerodynamic noise simulation problems,which is helpful to achieve high precision,fast and efficient numerical simulations of the airliner.