The Rolls-Royce RB.162 is a lightweight British turbojet engine produced by Rolls-Royce Limited. Developed in the early 1960s, it was specially designed for use as a lift engine for VTOL aircraft but was also used in a later variant of the Hawker Siddeley Trident airliner as an auxiliary boost engine. A smaller related variant, the RB.181 remained a design project only, as did a turbofan version designated RB.175.
The thermal efficiency is expressed mathematically as:
where:
- is the thermal efficiency,
- is the thrust produced by the engine,
- is the jet velocity,
- ṁf is the mass flow rate of fuel,
- is the specific enthalpy of the fuel.