Experimental study on a hybrid vortex reducer system in reducing the pressure drop in a rotating cavity with radial inflow

Abstract

To improve the work performance of the air bleed system (ABS) in an aero-engine, a new type of hybrid vortex reducer system (HVR) is designed, and related experimental tests are conducted. The design of the HVR is based on traditional vortex reducer systems, which are composed of de-swirl shroud orifices and short tubes.In the HVR, the de-swirl orifices cause the air moving through the rotating shroud to be smoother, and they suppress the tangential velocity of the air in the high radius region, while the short tubes decrease the tangential velocity of the air in the lower radius region. The experimental results show that when the turbulent flow parameter is in the range of 0.1–0.3, the average overall pressure drop coefficient in the HVR is only 59% compared with that of a tubeless vortex reducer system, only 74% compared with that of a traditional tubed vortex reducer system, which has longer tubes installed, and only 57% compared with that of another tubed vortex reducer system with the same short tubes as the HVR. Additionally, the monotonicity of the pressure drop with an increasing mass flow rate in the HVR is substantially better than that of the tubeless vortex reducer system, although the de-swirl devices are used in both configurations.