Performance testing of double- windscreen using empirical data

摘要

The improved performance of the rather larger prototype secondary windscreen used in these tests are probably a surprise to most. We suspect that this is because the performance figures from the ISVR study are largely believed to translate for all types of noise assessments. However, because ETSU-R-97 assessment specifically uses L^o parameter, it can be concluded that this parameter alone reduces the wind-induced noise levels because these levels are varying over time due to the turbulent nature of wind. Various "home-made" secondary windscreens have been used on several, but not all, ETSU-R-97 assessments. However, without detailed specification on design of secondary windscreens it has left open the possibility that each individual secondary windscreen arrangement could be contributing its own unique coloration on the data collected.