Search results
Results from the WOW.Com Content Network
The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle . The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and a turbine (that drives the compressor).
In a jet engine, each major rotating section usually has a separate gauge devoted to monitoring its speed of rotation. Depending on the make and model, a jet engine may have an N 1 gauge that monitors the low-pressure compressor section and/or fan speed in turbofan engines.
The Pratt & Whitney JT8D is a low-bypass (0.96 to 1) turbofan engine introduced by Pratt & Whitney in February 1963 with the inaugural flight of the Boeing 727.It was a modification of the Pratt & Whitney J52 turbojet engine which powered the US Navy A-6 Intruder and A-4 Skyhawk attack aircraft.
This improved the sustained turn rate by 15 per cent, the climb rate by 36 per cent, medium-level acceleration by 27 per cent and low-level speed with 18 bombs from 1,046 km/h to 1,120 km/h (654 - 700 mph or 565 kn to 605 kn). It was demonstrated at the Paris Air Show in 1987.
Rolls-Royce Avon early jet engine showing 1 of 2 sets of 3 valves at the top and 1 of 2 valves at the bottom which release some air from the compressor, pressure ratio 7.45:1, for starting and low speed running. Also visible at the front is the row of bearings for the variable inlet guide vanes.
The turboprop at its best flight speed gives significant fuel savings over a turbojet even though an extra turbine, a gearbox and a propeller are added to the turbojet's low-loss propelling nozzle. [24] The turbofan has additional losses from its greater number of compressor stages/blades, fan and bypass duct. [clarification needed]
This was a modified version of the RD36-51A engine with an unregulated nozzle and oxygen supply to the combustion chamber. The engine provided long-duration operation at an altitude of 26,000 m (85,000 ft) at low flight speed (M = 0.6). P = 7,000 kgf (15,000 lbf; 69,000 N) With beats. vsl. = 0,88 kg / kgf • h.
Thus civil turbofans today have a low exhaust speed (low specific thrust – net thrust divided by airflow) to keep jet noise to a minimum and to improve fuel efficiency. Consequently, the bypass ratio (bypass flow divided by core flow) is relatively high (ratios from 4:1 up to 8:1 are common), with the Rolls-Royce Trent XWB approaching 10:1. [7]