Complete flow conditioning gauzes

Abstract

This paper presents a novel method that can completely condition the flow into a turbomachinery experiment. A single, thick, 3D-printed gauze can be tailored to provide an exact stagnation pressure profile, flow angle distribution and turbulence intensity. The new method is superior to existing techniques as it provides accurate and cheap flow conditioning in just one component. It removes the requirement for separate endwall boundary layer generators, inlet guide vanes and turbulence grids. The paper is presented in two parts: first, the methods for designing complete flow conditioning gauzes are presented. Both 1D correlations and 3D CFD are used to design the vanes which form the gauze. The exit angle of the individual vanes is used to determine the whirl angle of the flow. Thickness is used to determine the mixing loss and thus achieve the pressure distribution and turbulence intensity. In the second part, two gauzes are designed and manufactured for two compressor testing applications. The first design is used to simulate a multi-stage embedded profile. This means that engine realistic flow conditions can be set up in a single stage compressor rig. The second design simulates the hub side stagnation pressure deficit that occurs at inlet to a core compressor downstream of an aero engine fan. Both applications demonstrate the fine control that can be achieved in an experiment using these gauzes.Graphical abstract