Study On Mesh Deforming Algorithm And Multi-physical Field Coupling Method In Aircraft Icing Simulation

The formation of ice on aircraft is a natural phenomenon during the flight,which can bring significant potential safety hazards,and may cause crash in some serious cases.Aircraft icing has become an important research topic in the aviation industry.The experimental methods based on icing wind tunnel and the application of flight test methods are limited to some extent because the costs and experimental conditions.The numerical simulation based on CFD method has become an important research method for studying aircraft icing problems under the development of computer technology and numerical calculation methods.Since the aerodynamic shape of the structure tends to be more complicated after icing,the grid reconstruction method in CFD is highly demanded.Meanwhile the calculation of the icing process requires the coupling of CFD solver and icing thermodynamic solver.There is an urgent need for a multiphysics coupling method suitable for large-scale parallel computing.In this paper,the above two problems aye studied,and the flow field mesh reconstruction method after icing is studied to improve the quality of the mesh,so as to achieve a better prediction of ice shape after multi-step ice accumulation.The coupling method of multiple physical fields in the freezing process is studied.The flow field calculation module,the icing calculation module and the grid reconstruction module are coupled together to coordinate the data transmission and synchronization among the modules and realize the efficient coupling calculation among various software.The research work of this paper mainly includes:1.The watermark trajectory,collision and collection coefficient solving program based on the Lagrangian method was developed.The classical Messinger icing thermodynamic model was used to calculate the icing thickness and the displacement of the airfoil boundary point through the mass and energy conservation equations.The program was verified and used in the later icing simulation.2.A dynamic mesh method based on diffusion equation was developed to update the CFD grid after icing.The diffusion equation was used to describe the nodal displacements and solved by the finite element method.The the nodal rotation was modeled and solved with the same method after analyzing the uncoupling between the different nodal displacement components to improving the mesh quality.3.Based on the remote procedure call technology,a multi-physics coupling platform was developed to accerating the icing simulation by combining the CFD,the icing calculation and the grid reconstruction program.4.The verification of some typical icing problem were performed,the results indicated that the proposed method and calculation program have better calculation accuracy and adaptability.