Analysis of fluid-solid-thermal coupling characteristics of axial-symmetric vectoring exhaust nozzle

Abstract

Aiming at the problems of axial-symmetric vectoring exhaust nozzle (AVEN) mechanism due to its complex structure, which leads to the large amount of digital simulation calculation under the coupling of multi-physics, and it is difficult to establish the fluid domain model, a complex AVEN structure is proposed as the research object, the method of AVEN flow field simplify model in cylindrical coordinate system. This method simplifies the contact domain between the expansion regulator plate, the cruciform joint, the convergent regulator plate and the flow field into a cylindrical overall physical model, and constructs a fluid-solid coupling heat transfer physical model. The feasibility of the model is verified. The AVEN fluid-solid-thermal coupling digital simulation calculation is carried out using the sequential one-way coupling method. First, based on computational fluid dynamics, the AVEN fluid-solid coupling heat transfer calculation is carried out to calculate the coupling surface temperature and pressure field. Second, the calculated coupling surface temperature is used as the thermal analysis boundary condition. Then, the temperature field calculated by the thermal analysis and the pressure field calculated by the fluid-solid coupling heat transfer analysis are used as the boundary conditions of the structural strength analysis. Finally, fluid-solid-thermal coupling analysis of AVEN including aerodynamic load and thermal load is carried out. The calculation results show that the digital simulation method proposed in this paper can be used in engineering practice. The temperature and pressure of the AVEN coupling surface show a trend of first decreasing, then increasing, and then decreasing with the change of the position from the throat. Some AVEN mechanical components and parts have stress singular phenomena. The deformation of the AVEN structure is obviously affected by the thermal load, and the minimum change of rate is 9.54%, the maximum change of rate is 1845.37%.