Natural laminar flow nacelle appearance determination method and system

Abstract

The invention discloses a natural laminar flow nacelle appearance determination method and system. The method comprises the following steps of: parameterizing a section of a to-be-improved nacelle byadoption of a CST method, and obtaining a position of a transition of the natural laminar flow nacelle through a gamma-Re theta transition model; obtaining boundary conditions of an air inlet and an engine outlet; obtaining variable groups by adoption of a Latin square design method; obtaining corresponding nacelle resistance according to the variable groups; establishing a first Kriging responsesurface model; obtaining a variance of the nacelle resistance corresponding to the variable groups; establishing a second Kriging response surface model; determining a target function, and predictinga mean value and a variance of the nacelle resistance by utilizing the first Kriging response surface model and the second Kriging response surface model; obtaining a variable group which enables a function value the target function to be the minimum, so as to obtain an optimal variable group; determining an appearance of the natural laminar flow nacelle according to parameters in the optimal variable group. The method and system are capable of effectively improving the performance of appearances of laminar flow nacelles, decreasing the skin friction resistance of airplanes and improving the economic efficiency of the airplanes.

Description

technical field [0001] The invention relates to the field of aircraft nacelle design, in particular to a method and system for determining the shape of a natural laminar flow nacelle. Background technique [0002] Large transport aircraft is the most competitive field in the international aviation industry. The challenge it faces in its development is how to meet the increasingly stringent requirements in terms of economy, safety, comfort, and environmental protection. For example, NASA plans to reduce the fuel consumption of the next three generations of civil transport aircraft by 33%, 40%, and 70% respectively compared with the current B737. To meet these stringent requirements, it is necessary to strengthen the design and research of improving the aerodynamic efficiency of the aircraft. [0003] Reducing aerodynamic drag has always been one of the most active research hotspots in the field of aerodynamics. The research results of the A340 show that a 0.3% reduction in dr...

AI Technical Summary

Problems solved by technology

Studies by NASA Obara et al. have shown that enlarging laminar flow over the surface of a typical commercial jetliner has the potential to reduce overall drag by (12-14)%

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