Method for analyzing wing structure aero-elasticity stability based on aerodynamic force uncertain order reduction

Abstract

The invention discloses a method for analyzing wing structure aero-elasticity stability based on aerodynamic force uncertain order reduction. The method is based on unsteady aerodynamic force model order reduction method based on CFD technology; uncertainty of numerical calculation and aerodynamic parameters during aerodynamic force identification process is taken into comprehensive consideration and is uniformly quantified as an uncertain bounded interval noise sequence in an identification model; uncertain order reduction of the aerodynamic force model is realized by means of interval set membership identification algorithm; unsteady aerodynamic uncertain order reduction model based on CFD technology is established; mathematical model of uncertain aero-elasticity system of state space form is established coupled with structural motion equation; an effective method for predicting system robustness stability boundary from the prospective of section state matrix characteristic values. The aero-elasticity system uncertainty modeling thinking and stability boundary prediction technology provided by the invention gives consideration to calculation efficiency, analysis precise and system robustness.

Description

technical field [0001] The invention relates to the field of aeroelastic robust stability analysis of wing structures, in particular to an analysis method for aeroelastic stability of wing structures based on aerodynamic uncertainty reduction. Background technique [0002] Aeroelasticity mainly studies the response and stability of elastic structures under the coupling effects of aerodynamic force, elastic force and inertial force. It is closely related to the development of modern aircraft technology. Dynamic stability, commonly known as flutter, is a branch of aeroelasticity that has received much attention, and it is also one of the first issues that need to be considered in the design of modern aircraft. From the point of view of vibration, flutter is a kind of self-excited vibration of elastic structure under the action of unsteady aerodynamic force, and unsteady aerodynamic force plays a very key role in this process. Therefore, establishing an accurate and efficient ...

AI Technical Summary

Problems solved by technology

Various unsteady aerodynamic models based on linearization theory developed in the 20th century are widely used in the aeroelastic analysis of engineering structures because of their simple modeling and small amount of calculation. However, such models are not suitable for transonic flow, Nonlinear aeroelastic problems under conditions of high angle of attack flight, airflow separation, etc.

Probabilistic flutter analysis treats uncertain quantities as random variables satisfying a certain probability distribution, with the purpose of obtaining an optimistic "soft" stability boundary in the sense of probability, within which the aeroelastic system cannot be guaranteed to be absolutely safe

The main disadvantage of probabilistic flutter analysis is that it relies too much on the prior information of the uncertainty quantity, and needs to obtain the distribution law of the uncertainty quantity in advance through a large number of sample experiments

Images