Compressor map

A compressor map is a chart created for a compressor in a gas turbine engine. Complete maps are based on compressor rig test results or predicted by a special computer program. Alternatively the map of a similar compressor can be suitably scaled. A compressor map is a chart created for a compressor in a gas turbine engine. Complete maps are based on compressor rig test results or predicted by a special computer program. Alternatively the map of a similar compressor can be suitably scaled. Compressor maps are an integral part of predicting the performance of a gas turbine engine, both at design and off-design conditions. Fans and turbines also have operating maps, although the latter are significantly different in appearance to that of compressors. The x-axis is usually some function of compressor entry mass flow, usually corrected flow or non-dimensional flow, as opposed to real flow. This axis can be considered a rough measure of the axial Mach number of the flow through the device. Normally the y-axis is pressure ratio (Pexit/Pinlet), where P is stagnation (or total head) pressure.