Effect of Flange Vibration on Airflow Passing Through a Diffuser With Known Geometry

Abstract

A diffuser-augmented wind turbine is used to enhance the overall performance characteristic of the wind turbine. Flanges near the trailing end of the diffuser create a pressure difference that accelerates the free-stream velocity into the diffuser, increasing the performance of the wind turbine. In the present analysis, a numerical method is used to analyze the effect of flange vibration at different amplitude and operating frequencies. The diffuser is operated at no-load (<i>C</i><sub>t</sub> = 0) condition for all cases. An optimum opening angle is determined in the absence of flange vibration at a constant airflow rate and is used for further analysis. Performance characteristics such as diffuser speed-up ratio and coefficient of power are estimated for all cases. It is found that the velocity at the centerline oscillates with the same frequency as that of the flange.