The Manufacture of Glass Fibre Rotor Blades with Pressure Tappings

Abstract

In university research on the flow through turbo-machines it is often necessary to produce blades which can be manufactured in a small workshop at relatively low cost. As part of a project to investigate the development of the annulus wall boundary layers in a compressor, a set of rotor blades were designed and manufactured for the large rotating cascade wind tunnel at Cambridge University. The apparatus is shown in outline in Fig. 1 and a detailed description of this wind tunnel has been given by Oxford. The air passes through the research rotor and then through the auxiliary fan and throttle. The combination of a variable speed research rotor with variable speed and pitch on the auxiliary fan and variable throttle leads to a highly versatile apparatus with a wide range of operation. An important feature of this apparatus is the sixteen channel pressure transfer device which allows pressures measured on the rotating blade to be transmitted out to a stationary multi-tub manometer.