Practical Aspects of Cascade Wind Tunnel Research

Abstract

This paper deals mainly with the development of a high-speed wind tunnel for the testing of turbine or compressor blade cascades under two-dimensional air flow at velocities up to that of sound. It includes a brief resume of the early history of the technique, and goes on to enumerate the variables which must be brought under the operator's control. Reference is made to methods of presentation of results, including the use of optical systems for demonstration of shock phenomena. Finally, the control system evolved for operating the high-speed tunnel is described, and some notes are added on the protection of the operators from fatigue induced by monotony and noise.

Experimental and Numerical Investigation of a Compressor Cascade at Highly Negative Incidence

“…Traditionally, cascades of blades in linear or annular configuration were employed for the experimental understanding of the complex flow phenomena and the derivation of their performance under various operating conditions (Todd, 1947). A huge range of instrumentation approaches as well as of wind tunnel configurations are recorded throughout the literature, implying the depth of the experimental studies performed by different research groups (Carter, 1950;Sieverding, 1985) in this direction.…”

Analysis of the Near-Wall Flow in a Turbine Cascade by Splat Visualization

“…Since measurements in rotating rows of blades are complicated, a traditional approach in the field, when desiring to conduct fundamental studies, is to consider so-called linear cascades [33]: In a wind tunnel with two parallel walls, straight blades are mounted in parallel from wall to wall. While far from the side walls the flow is two-dimensional, various kinds of secondary flows exist close to the side walls.…”