Influence of the wakes of rotating spokes on the performance of a turbine exhaust diffuser

• 作 者: M.Kuschel J.R.Seume
• 机 构: Institute of Turbomachinery and Fluid Dynamics,Leibniz University Hannover,D-30167 Hannover,Germany,
• 出 处: Journal of Thermal Science
• 发表日期: 2010年03期
• 关键词: turbine rotating exhaust annular conservative spoke wheel installed blade approx

The design of turbine exhaust diffusers is still commonly based upon conservative design charts which do not consider the influence of the components installed upstream such as the last turbine stage.Based on investigations with different spoke wheels which approximate the blade wakes of the last turbine stage,the influence of a rotating bladed disc on the flow in a exhaust diffuser is presented.The pressure recovery for an annual diffuser with 15° half cone angle and the 5 mm spoke wheel used in the model test is very high and nearly independent on the rotational speed and the corresponding Strouhal number.For a 20° annual diffuser,the pressure recovery increases with Strouhal number

The design of turbine exhaust diffusers is still commonly based upon conservative design charts which do not consider the influence of the components installed upstream such as the last turbine stage. Based on investigations with different spoke wheels which approximate the blade wakes of the last turbine stage, the influence of a rotating bladed disc on the flow in a draft diffuser is presented. pressure recovery for an annual diffuser with 15 ° half cone angle and the 5 mm spoke wheel used in the model test is very high and near independent on the rotational speed and the corresponding Strouhal number. For a 20 ° annual diffuser, the pressure Recovery increases with Strouhal number