Design and operation of a counter-rotating aspirated compressor blowdown test facility

Abstract

A unique counter-rotating aspirated compressor was tested in a blowdown facility at the Gas Turbine Laboratory at MIT. The facility expanded on experience from previous blowdown turbine and blowdown compressor experiments. Advances in thermocouple and facility designs enabled efficiency estimates through total temperature and total pressure measurements. The facility was designed to provide at least 100 ms of available test time, approximately a factor of five greater than previous blowdown compressor facilities. The adiabatic core efficiency of the compressor was estimated with an uncertainty of 0.8% and the corrected flow was estimated with an uncertainty of 1.0%. The compressor was tested at several operating conditions and two speed lines were partially mapped. The maximum measured total pressure ratio across the two stages was 3.02 to 1. The measured adiabatic efficiency for that point was 0.885. The span-wise total pressure, total temperature, and efficiency profiles were compared to the predicted profiles for runs with the corrected speeds of the two rotors at 90% of design and 100% design. There appears to be reasonable agreement between the predictions and the measurements.