The Time Constant of a Streamer

Abstract

With a view to investigating the characteristics of a streamer as a wind-direction indicator, a model of cylindrical streamer is tested in the wind tunnel concerning the time constant of its performed damped oscillation in the tunnel current. For comparison a stiff cylindrical wind vane of precisely the same dimensions is also tested. The measurement is carried out in four steps of wind speed up to 20m/s. It is found that the time constant of the streamer is utterly constant independent of wind speed, which fact stands in contrast to the case of most wind vanes where the time constant is inversely proportional to the wind speed.