A helicopter aerodynamic layout optimization method that can reduce the adverse effects of aerodynamic interference

Abstract

The present invention discloses a helicopter aerodynamic layout optimization method capable of reducing the adverse effect of aerodynamic interference. According to the method, aiming at the defects of a wind tunnel test and a CFD method and based on a discrete vortex method and a surface element method, a coupled aerodynamic interference high-precision analysis model for a helicopter is set up, so that the influence of aerodynamic interference on the helicopter can be considered only by simulating calculation without carrying out the wind tunnel test; compared with the CFD method, the method has the advantages of greatly reducing the requirements of a simulation model for computing resources and shortening computing time. In order to further reduce calculated amount and a optimization region, a helicopter fuselage shape parameter model is set up by a parametric method and a combined optimization method based on an agent model is adopted, so that the optimal helicopter aerodynamic outline and layout are obtained and the purpose of reducing aerodynamic interference to improve the flight characteristics of the helicopter is achieved. The helicopter aerodynamic layout optimization method can be applied to the conceptual design phase of the helicopter so as to improve the flight characteristics, the balancing characteristic, stability and manoeuvrability of the helicopter.

Description

technical field [0001] The invention belongs to the field of helicopter aerodynamic layout design, in particular to a helicopter aerodynamic layout optimization method capable of reducing the adverse effects of aerodynamic interference. Background technique [0002] Helicopters work in a complex, unsteady vortex field in which the influence of the wake generated by the rotor dominates. The wake of the rotor either directly hits the fuselage or passes close to the fuselage, and there will be serious mutual aerodynamic interference between the various parts of the helicopter. The aerodynamic interference of the helicopter will directly affect the flight performance, trim and control characteristics of the helicopter. As the helicopter develops towards a more compact overall layout, greater paddle load, and higher flexibility and maneuverability, the problem of aerodynamic interference between the helicopter and its components will become more serious. Therefore, it is of gre...

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Problems solved by technology

However, most of these studies are based on the discrete vortex method with incompressible and inviscid assumptions. For the rotor wake, the viscous effect needs to be considered through the vortex core model, and different vortex core models have a great impact on the calculation accuracy and numerical stability of the wake.

[0005] In the traditional optimization method, the gradient method can quickly find the optimization, but if there are multiple extreme values ​​in the design space, the gradient method is likely to make the optimization process fall into a local optimal solution; while the global optimization method can be well in the whole Find the global optimal solution in the design space, but there are efficiency problems in detail optimization. If there are too many design parameters, the calculation amount of the optimized design space will increase sharply, and the calculation model of the helicopter flight performance, trim and control characteristics will be computationally intensive. , if the simulation model is directly used in the optimization process, the entire optimization time and calculation amount will be extremely large, and it is difficult to use it in engineering design

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