Challenges of creating realistic periodical unsteady inflow conditions in a linear compressor cascade

Authors

Andreas Krug - Technische Universität Dresden, Chair of Turbomachinery and Flight Propulsion
Peter Busse - Technische Universität Dresden, Chair of Turbomachinery and Flight Propulsion
Martin Lange - Technische Universität Dresden, Chair of Turbomachinery and Flight Propulsion
Konrad Vogeler - Technische Universität Dresden, Chair of Turbomachinery and Flight Propulsion
Ronald Mailach - Technische Universität Dresden, Chair of Turbomachinery and Flight Propulsion

Abstract

The paper presents results of an experimental investigation into the effects of a periodic wake induced inlet disturbance on the tip leakage flow in a linear compressor cascade. A translatory wake generator, being equipped with circular cylinders, is used to produce the unsteady inflow. The setup resembles the kinematic conditions found in the compressor rotor tip region. A variation of the flow coefficient ϕ is considered to account for effects arising from inappropriately oriented wake trajectories. The evaluation of the cascade flow field mainly relies on five-hole probe and two-dimensional CTA probe data. Differences in the resulting inlet conditions are discussed in the context of the steady and time-resolved leakage flow characteristics being strongly dependent on ϕ. The interaction between the moving bar wakes and the sidewall boundary layer is suggested to cause the absence of any periodic interaction for realistic values of ϕ in this configuration.