Integrated engine pressure ratio

The integrated engine pressure ratio (IEPR) is the ratio of the pressure at the core engine exhaust and fan discharge pressure compared to the intake pressure to the gas turbine engine. The IEPR is an engine indicator system unique to the Rolls-Royce RB211.

In most gas turbine engines the engine pressure ratio (EPR) is used instead, which is the core engine exhaust pressure compared to the intake pressure to the gas turbine engine.

See also

• Jet engine performance
• Turbofan

References

• Rolls Royce Method for evaluating the working line characteristics of a compressor of a gas turbine engine US Patent 5010727
• The Boeing Company Engine thrust control system US Patent 4248042 Includes Boeing's discussion on EPR or IEPR being a better indicator of thrust.
• Pressure Variation EPR - NASA Animation