A Non-Gaussian Gust Model for Aircraft Response Analysis

Abstract

N UMEROUS investigations have been performed on the dynamic response of aircraft to continuous atmospheric turbulence (gust) by assuming that the turbulence field can be modeled as one, or a number of individually Gaussian and stationary patches. However, the observed statistical properties of atmospheric turbulence encountered by aircraft, especially those with the highest severity and potentially most destructive, are in many cases non-Gaussian. For instance, Ref. 1 deals with the aeronautical effects of surface winds and gusts. Tke investigation revealed that turbulence can rarely be realistically represented by a Gaussian process. This paper describes a non-Gaussian model for continuous atmospheric turbulence based on zero-memory transformation of a Gaussian model. Single or multiple transformation parameters are used to control the severity and other statistical characteristics of the non-Gaussian process. The composite nature of gust patches of various intensity is accounted for through the accumulative statistics. Methods to predict the aircraft response statistics to the non-Gaussian gust model are developed by approximating the response integral as its Riemann sum. Application of the probabilistic theory indicates that the statistical properties of response can be expressed in multifold integral forms and its moments can be expressed in explicit forms.