Topic
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.
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TL;DR: A Williams International FJ44-3A turbofan engine was used to demonstrate the high-speed fan noise reduction potential of a foam-metal liner installed in close proximity to the fan rotor as mentioned in this paper.
Abstract: A Williams International FJ44-3A turbofan engine was used to demonstrate the high-speed fan noise reduction potential of a foam-metal liner installed in close proximity to the fan rotor. The engine was tested in the NASA Glenn Research Center’s Aeroacoustic Propulsion Laboratory. Two foam-metal liner designs were tested and compared to the hardwall baseline. Traditional single degree-of-freedom liner designs were also evaluated to provide a comparison to the state-of-the art design. This report presents the test setup and documents the test conditions. Far-field acoustic levels and limited engine performance results are also presented. The results show that the foam-metal liner achieved up to 5 dB of attenuation in the forward-quadrant radiated-acoustic power levels, which is equivalent to the traditional single degree-of-freedom liner design. Modest changes in engine performance were noted.
51 citations
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26 Oct 1970TL;DR: An afterburner construction for a turbine engine such as a turbofan engine is foreshortened by using a construction which utilizes swirl flow phenomena to rapidly mix the engine products of combustion and coolant flow, such as fan air, while maintaining engine performance and structural part integrity as mentioned in this paper.
Abstract: An afterburner construction for a turbine engine, such as a turbofan engine, which is foreshortened by using a construction which utilizes swirl flow phenomena to rapidly mix the engine products of combustion and coolant flow, such as fan air, and/or to rapidly accomplish the afterburning combustion process in the afterburner, while maintaining engine performance and structural part integrity.
51 citations
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TL;DR: In this article, a transient dynamic analysis of a fan blade-out event highlights the complexity of the numerical technique, which includes all the nonlinearities of structural dynamics: plastic behavior of the materials, large displacemen, etc.
Abstract: In accordance with the FAA certification requirements, all modern commercial turbofan engines must successfully demonstrate its ability to withstand a fan blade-out (FBO) event through actual test. Possibility of losing a rotating fan blade from a running engine is a flight safety consideration, which must be addressed during the design phase of the engine. A typical fan blade-out event involves very complex nonlinear transient dynamics with large deflection of the release blade and rigid body rotation of the trailing blade as well as progressive failure and fragmentation of various components. Due to the nature of the impact type loading, the solution to the problem should also address dependence of the material behavior such as yield strength as a function of strain rates. In short, the transient dynamic analysis of a fan blade-out event highlights the complexity of the numerical technique, which includes all the nonlinearities of structural dynamics: plastic behavior of the materials, large displacemen...
51 citations
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TL;DR: In this paper, a team approach has been used to develop a family of two nickel-base single crystal alloys (CMSX-4® containing 3 percent Re and CMSX®-10 containing 6 percent Re) and a directionally solidified, columnar grain nickel base alloy (CM 186 LC® containing three percent Re), for a variety of turbine engine applications.
Abstract: Turbine inlet temperatures over the next few years will approach 1650°C (3000°F) at maximum power for the latest large commercial turbofan engines, resulting in high fuel efficiency and thrust levels approaching 445 kN (100,000 lbs.) High reliability and durability must be intrinsically designed into these turbine engines to meet operating economic targets and ETOPS certification requirements. This level of performance has been brought about by a combination of advances in air cooling for turbine blades and vanes, design technology for stresses and airflow, single crystal and directionally solidified casting process improvements, and the development and use of rhenium (Re) containing high γ' volume fraction nickel-base superalloys with advanced coatings, including full-airfoil ceramic thermal barrier coatings. Re additions to cast airfoil superalloys not only improves creep and thermo-mechanical fatigue strength, but also environmental properties including coating performance. Re dramatically slows down diffusion in these alloys at high operating temperatures. A team approach has been used to develop a family of two nickel-base single crystal alloys (CMSX-4® containing 3 percent Re and CMSX®-10 containing 6 percent Re) and a directionally solidified, columnar grain nickel-base alloy (CM 186 LC® containing 3 percent Re) for a variety of turbine engine applications. A range of critical properties of these alloys is reviewed in relation to turbine component engineering performance through engine certification testing and service experience. Industrial turbines are now commencing to use this aero developed turbine technology in both small and large frame units in addition to aero-derivative industrial engines. These applications are demanding, with high reliability required for turbine airfoils out to 25,000 hours, with perhaps greater than 50 percent of the time spent at maximum power. Combined cycle efficiencies of large frame industrial engines are scheduled to reach 60 percent in the U.S. ATS programme. Application experience to a total 1.3 million engine hours and 28,000 hours individual blade set service for CMSX-4 first stage turbine blades is reviewed for a small frame industrial engine.
51 citations
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03 Oct 2002TL;DR: In this paper, a system and method for preventing the formation of ice on or removing ice from an internal surface of a turbofan engine is described, where electric coils are installed within the resin to prevent ice build-up on the splitter region.
Abstract: A system and method are provided for preventing the formation of ice on or removing ice from an internal surface of a turbofan engine. A splitter region, associated with a booster compressor of the turbofan engine, is identified. The splitter region has surfaces internal to the turbofan engine subject to inlet icing conditions. A resin is molded along a leading edge of the splitter region, and electric coils are installed within the resin to prevent ice build-up on the splitter region or to remove ice from the splitter region during icing conditions.
51 citations