Experimental Investigation on Aerodynamic Behavior of a Compressor Cascade in Droplet Laden Flow

Abstract

The possibility to augment the power output of gas turbines by the use of water injection becomes more and more attractive in recent years as unsteadily available renewable energy sources become more present and the need of reserve power rises. Depending on the installed system, water injection may result in a two phase flow inside the compressor. The water droplet laden compressor flow promises benefits in efficiency and to some extent in performance and stability. A promising approach is the stabilizing influence on highly stressed airfoils as experimentally and numerically investigated by different research groups. Multiple numerical investigations have been undertaken by different research groups which found similar results. The ongoing experimental investigation presented in this paper focuses on the influence of a droplet laden flow on an axial compressors' aerodynamics over the range of relevant incidence flow angles. The result of the series of experiments is a comparison of a dry air compressor flow and a droplet laden air compressor flow at high velocity (Ma>0.85). The variables were water load and incidence angle. The discussion will investigate the effects of the presence of water droplet on the compressor cascade's discharge flow properties and their influence on the relevant performance parameters. For this a discussion of the loss coefficient the detailed discharge flow velocity and the axial velocity density ratio will take place.