US 2022/0033062 A1 · METHOD AND SYSTEM FOR DETERMINING HELICOPTER ROTOR AIRFOIL

Abstract

The present disclosure provides a method and system for determining a helicopter rotor airfoil. The method includes: randomly generating a sample point by using a Latin hypercube sampling (LHS) method (S1); determining characterization equations of upper and lower airfoil surfaces of an airfoil based on the airfoil sample point by using a class shape transformation (CST) method (S2); performing dynamic characteristic simulation on the airfoil according to the characterization equations of the upper and lower airfoil surfaces by using a computational fluid dynamics (CFD) method, to obtain a flow field characteristic of the airfoil (S3); establishing a mapping relationship between the sample point and the flow field characteristic by using a Kriging model, and training the mapping relationship by using a maximum likelihood estimation method and an expected improvement (EI) criterion, to obtain a trained mapping relationship (S4); determining an optimal sample point based on the trained mapping relationship by using Non-dominated Sorting Genetic Algorithm II (NSGA-II) (S5); and determining a rotor airfoil based on the optimal sample point (S6). The method performs optimized design on aerodynamic characteristics of the airfoil in a state with a changing incoming flow and a changing angle of attack, and can effectively alleviate dynamic stall in this state.

Claims10

Dependent claims

A method for determining a helicopter rotor airfoil, comprising:

randomly generating a sample point by using a Latin hypercube sampling (LHS) method;
determining characterization equations of upper and lower airfoil surfaces of an airfoil based on the sample point by using a class shape transformation (CST) method;
performing dynamic characteristic simulation on the airfoil according to the characterization equations of the upper and lower airfoil surfaces by using a computational fluid dynamics (CFD) method, to obtain a flow field characteristic of the airfoil, wherein the flow field characteristic comprises a lift coefficient, a drag coefficient, and a moment coefficient;
establishing a mapping relationship between the sample point and the flow field characteristic by using a Kriging model, and training the mapping relationship by using a maximum likelihood estimation method and an expected improvement (EI) criterion, to obtain a trained mapping relationship;
determining an optimal sample point based on the trained mapping relationship by using Non-dominated Sorting Genetic Algorithm II (NSGA-II), wherein the optimal sample point corresponds to an optimal flow field characteristic, and the optimal flow field characteristic comprises an optimal lift coefficient, an optimal drag coefficient, and an optimal moment coefficient;
and
determining a rotor airfoil based on the optimal sample point.

4 more elements

A system for determining a helicopter rotor airfoil, comprising:

a sample point generation module, configured to randomly generate a sample point by using an LHS method;
an airfoil surface equation determining module, configured to determine characterization equations of upper and lower airfoil surfaces of an airfoil based on the sample point by using a CST method;
a flow field characteristic calculation module, configured to perform dynamic characteristic simulation on the airfoil according to the characterization equations of the upper and lower airfoil surfaces by using a CFD method, to obtain a flow field characteristic of the airfoil, wherein the flow field characteristic comprises a lift coefficient, a drag coefficient, and a moment coefficient;
a mapping relationship calculation module, configured to establish a mapping relationship between the sample point and the flow field characteristic by using a Kriging model, and train the mapping relationship by using a maximum likelihood estimation method and an EI criterion, to obtain a trained mapping relationship;
a multi-objective optimization module, configured to determine an optimal sample point based on the trained mapping relationship by using NSGA-II, wherein the optimal sample point corresponds to an optimal flow field characteristic, and the optimal flow field characteristic comprises an optimal lift coefficient, an optimal drag coefficient, and an optimal moment coefficient;
and
an airfoil determining module, configured to determine a rotor airfoil based on the optimal sample point.

4 more elements

Dependencies are inferred from the claim text.

Method and system for determining helicopter rotor airfoil

Life of this patent

Method and system for determining helicopter rotor airfoil

Life of this patent

Abstract

Claims10