Abstract
In this paper three types of gust generators are tested in a wind-tunnel to examine their characteristics. The generators which were investigated are the flag method, turbulent-flow-glid method and their combined method. The gust velocities generated by these methods are measured using a hot wire anemometer of X type, and the characteristics of the power spectra are examined for several parameters such as wind velocity, the size and thickness of a flag. To estimate a gust model for controller designs, discrete models based on an ARMA process are first identified by the AIC method. A continuous model with a lower dimension is then derived by selecting the coefficients of a rational function. These selections are based on the quasi-Newton method which minimizes the square sum of errors at some discrete frequencies. It is found that the gust generators considered here can furnish one with a convenient mean for wind-tunnel experiments. In particular, the estimated gust model may be expected to provide a simple mathematical model for designing controllers.
