Variant aircraft aerodynamic optimization method based on improved position vector expectation improvement degree

Abstract

The invention discloses a variant aircraft aerodynamic optimization method for improving the expected improvement degree of a position vector, and belongs to the technical field of aircraft overall optimization. The method comprises the following steps: selecting an initial reference airfoil profile and a related shape coefficient, and determining a design working condition; establishing an optimization model considering structural consistency constraint to solve the shape coefficient of the deformed airfoil profile, and establishing a high-precision aerodynamic analysis model to solve the lift coefficient and the resistance coefficient of the airfoil profile; establishing a Kriging agent model of the high-precision pneumatic analysis model, optimizing the Kriging agent model to obtain a pseudo-non-dominated solution, and judging whether a prediction variance of the Kriging agent model is greater than a threshold value or not; and if the prediction variance is not less than the threshold, obtaining newly added sample points for updating the Kriging proxy model by adopting a position vector expectation improvement criterion, otherwise, screening the newly added sample points from the pseudo-non-dominated solution to update the Kriging proxy model. By screening newly added sample points, the precision of the Kriging agent model at the Pareto frontier is improved, the optimality and the distributivity of an optimized non-dominated solution are improved, meanwhile, the optimization efficiency is improved, and the cost is saved.

Description

technical field [0001] The invention relates to an aerodynamic optimization method for a variant aircraft based on improving the expected improvement degree of a position vector, and belongs to the technical field of overall aircraft optimization. Background technique [0002] Traditional aircraft generally adopt a fixed aerodynamic layout, and the optimal aerodynamic performance can only be achieved under specific flight conditions, and the ability to perform multiple tasks is limited. The morphing aircraft can independently change its aerodynamic shape according to different flight environments and combat tasks, thereby improving its aerodynamic performance. The variable-wing aircraft in the variant aircraft can adjust the lift-to-drag ratio by changing the camber or thickness of the airfoil to adapt to different flight conditions, or use the deformation of the front and rear edges of the airfoil to obtain different cambers of the front and rear edges of the airfoil, repla...

AI Technical Summary

Problems solved by technology

[0018] Aiming at the problems in the aerodynamic multi-objective optimization design of the variable-wing aircraft, the internal structure is insufficiently considered for the limitation of the deformation capability, and the calculation of the optimization process is complicated. The technical problem is to describe the constraints of the wing internal support structure and drive device on the deformation capability of the variable-wing aircraft by customizing the airfoil geometry parameterization method considering the structural consistency constraints, and through the multi-objective optimization based on the expected improvement of the improved position vector The method balances the distribution and optimality of the non-dominated solutions to realize the efficient optimization of the variable-wing aircraft. The aerodynamic performance of the airfoil aircraft under different flight conditions improves the ability of the aircraft to perform multiple tasks, making the airfoil aircraft have a wide range of practicability and versatility, thereby reducing the cost of research and development

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