Turbofan

About: Turbofan is a research topic. Over the lifetime, 4114 publications have been published within this topic receiving 39490 citations. The topic is also known as: fanjet & turbofan engine.

Method for reducing jet exhaust takeoff noise from a turbofan engine

Abstract: In a turbofan engine for jet aircraft the inner stream includes no noise suppression apparatus and the jet exhaust noise generated at takeoff is reduced by mechanically suppressing the jet exhaust noise of the outer stream and operating the engine at a bypass ratio, fan pressure ratio and gas generator power setting which yield a jet exhaust noise level from the suppressed outer stream which is louder than the jet exhaust noise level from the unsuppressed inner stream.

Geared turbofan with three turbines with high speed fan drive turbine

Abstract: gas turbine engine has a fan rotor, a first compressor rotor and a second compressor rotor and three turbine sections. A fan drive drives the fan through a gear reduction. The fan drive turbine section has a first exit area at a first exit point and is configured to rotate at a first speed. A second turbine section has a second exit area at a second exit point and is configured to rotate at a second speed that is faster than the first speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area. A ratio of the first performance quantity to the second performance quantity is between about 0.5 and about 1.5.

Assessment of Engine and Vehicle Performance Using Integrated Hybrid-Electric Propulsion Models

Abstract: NASA is actively funding research into advanced, unconventional aircraft and engine architectures to achieve drastic reductions in vehicle fuel burn, noise, and emissions. One such concept is being explored by The Boeing Company, the General Electric Company, Virginia Polytechnic Institute and State University, and the Georgia Institute of Technology under the Subsonic Ultra Green Aircraft Research Project. A major cornerstone of this research is evaluating the potential performance benefits that can be attributed to using hybrid-electric propulsion. Hybrid-electric propulsion in this context involves a non-Brayton power generation or storage source, such as a battery or a fuel cell that can be used to provide additional propulsive energy to a conventional Brayton-cycle-powered turbofan engine. This research constructs an integrated Numerical Propulsion System Simulation hybrid-electric propulsion model capable of predicting hybrid-electric engine performance throughout the operational envelope. The syste...

Turbofan jet engine with low pressure shaft passing outside of core engine

Abstract: A turbofan engine includes a core engine, having a high-pressure compressor, a combustion chamber and a high-pressure turbine which are coupled to one another via a high-pressure shaft, at least one fan from which gas is supplied into both a primary flow duct and a secondary flow duct of the turbofan engine, at least one low-pressure turbine arranged behind the core engine, and at least one low-pressure shaft, with each low-pressure shaft coupling a fan to a low-pressure turbine. It has been provided that no low-pressure shaft of the turbofan engine passes through the core engine.

Energy efficient engine: Fan test hardware detailed design report

Abstract: A single stage fan and quarter stage booster were designed for the energy efficient engine. The fan has an inlet radius ratio of 0.342 and a specific flow rate of 208.9 Kg/S sq m (42.8 lbm/sec sq ft). The fan rotor has 32 medium aspect ratio (2.597) titanium blades with a partspan shroud at 55% blade height. The design corrected fan tip speed is 411.5 M/S (1350 ft/sec). The quarter stage island splits the total fan flow with approximately 22% of the flow being supercharged by the quarter stage rotor. The fan bypass ratio is 6.8. The core flow total pressure ratio is 1.67 and the fan bypass pressure ratio is 1.65. The design details of the fan and booster blading, and the fan frame and static structure for the fan configuration are presented.