overall pressure ratio

The overall pressure ratio of the compression system is 24.3.

Thus, for a particular construction technology and set of flight plans an optimal overall pressure ratio can be determined.

For comparison, modern civil turbofan engines have overall pressure ratios of 44:1 or more.

Increasing the overall pressure ratio of the compression system raises the combustor entry temperature.

As a side-effect of these wide operating conditions, and generally older technology in most cases, military engines typically have lower overall pressure ratios.

T-stages are used to increase overall pressure ratio and, for a given core size, the core mass flow.

Increasing overall pressure ratio implies raising the high pressure compressor exit temperature.

This would allow an engine with a given overall pressure ratio to be built with fewer stages, making it smaller, lighter and less complex.

Alternatively, the core size can be increased, to raise core airflow, without changing overall pressure ratio.

Compression ratio and overall pressure ratio are interrelated as follows:

Further improvements in core thermal efficiency can be achieved by raising the overall pressure ratio of the core.

Generally speaking, a higher overall pressure ratio implies higher efficiency, but the engine will weigh more, so there is a compromise.

Thus turbojets can be made more fuel efficient by raising overall pressure ratio and turbine inlet temperature in union.

The engine has an overall pressure ratio of 35:1, which is extremely high for an engine with a centrifugal compressor.

The desired overall pressure ratio for the engine cycle is usually achieved by multiple axial stages on the core compression.

A high overall pressure ratio permits a larger area ratio nozzle to be fitted on the jet engine.

Increasing overall pressure ratio on jet engines tends to decrease SFC.

There is, however, a rise in nozzle pressure, because overall pressure ratio increases faster than the turbine expansion ratio.

Two extra booster stages were added to the LP (low pressure) compressor, which increased the overall pressure ratio to 29.3.

Early turbojet engines were very fuel-inefficient, as their overall pressure ratio and turbine inlet temperature were severely limited by the technology available at the time.

The Concorde's Olympus engines got additional compression from its supersonic inlet, yielding an effective overall pressure ratio of 80:1.

The increase in core size and overall pressure ratio significantly raised the core flow, resulting in a decrease in bypass ratio to 4.26.

A three shaft configuration (i.e. 2 spool gas generator) was chosen to maximize overall pressure ratio, whilst retaining a free power turbine.

On the other hand, adding a stage to the rear of the compressor increases overall pressure ratio, decreases core size, but has no effect on core flow.

Early turbojet compressors had overall pressure ratios as low as 5:1 (as do a lot of simple auxiliary power units and small propulsion turbojets today).