Summary

Description

Description: This facility consists of a large-scale, low-speed open-loop induction wind tunnel which has been modified to house a linear turbine cascade. A 125-hp electric motor powers an axial flow fan, drawing air at velocities up to 80m/s through an 85 cm by 122 cm test section. The entrance to the tunnel consists of a 3.0 m by 2.7 m rectangular bellmouth inlet. Honeycomb flow straighteners located in the inlet, combined with a gradual 8:1 area contraction, produce a uniform, low turbulence velocity profile at the cascade. Flow velocity uniformity is within ±1% with approximately 0.5% freestream turbulence. This level of turbulence can be augmented through the use of a turbulence-generating grid that produces freestream turbulence levels of approximately 4% at the cascade. The grid may also be fed with high-pressure air to produce turbulence levels of up to 15%. The inlet and test section pivot independently of the exit section, allowing the cascade inlet and exit to be set independently between 0° and 65°, allowing a total cascade turning of between 0° and 130°. The cascade is modular and can accommodate 85 cm span blades of up to 20 cm axial chord. A moving bar wake generator is available to provide periodic upstream unsteadiness over a wide range of reduced frequencies and flow coefficients. A modular splitter plate assembly may also be installed to allow the study of end-wall flows with controlled wall boundary layer conditions. Available instrumentation includes thermocouples, pressure probes, thermal anemometry, and Particle Image Velocimetry. Access is also available for use of a wide range of optical instrumentation techniques. Purpose: This facility is used to perform studies of turbine aerodynamics and flow control. Products: Low Reynolds number and high loading turbine component aerodynamics data. Data on the effects of periodic unsteadiness on turbine performance. Flow control data for application to turbine component design.