scispace - formally typeset
Search or ask a question
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.


Papers
More filters
30 Aug 2013
TL;DR: The Unducted Fan (UDF) engine as mentioned in this paper is an aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration.
Abstract: The Unducted Fan (UDF) engine is an innovative aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration. This engine is being developed to provide a high thrust-to-weight ratio power plant with exceptional fuel efficiency for subsonic aircraft application. This report covers the successful ground testing of this engine. A test program exceeding 100-hr duration was completed, in which all the major goals were achieved. The following accomplishments were demonstrated: (1) full thrust (25,000 lb); (2) full counterrotating rotor speeds (1393+ rpm); (3) low specific fuel consumption (less than 0.24 lb/hr/lb); (4) new composite fan design; (5) counterrotation of structures, turbines, and fan blades; (6) control system; (7) actuation system; and (8) reverse thrust.

14 citations

01 Jan 2002
TL;DR: The Source Diagnostic Test (NDT) as discussed by the authors was conducted in the NASA Glenn Research Center 9- by 15-foot Low Speed Wind Tunnel at velocities simulating the takeoff and approach phases of the aircraft flight envelope.
Abstract: The design of effective new technologies to reduce aircraft propulsion noise is dependent on an understanding of the noise sources and noise generation mechanisms in the modern turbofan engine. In order to more fully understand the physics of noise in a turbofan engine, a comprehensive aeroacoustic wind tunnel test program was conducted called the “Source Diagnostic Test.” The test was cooperative effort between NASA and General Electric Aircraft Engines, as part of the NASA Advanced Subsonic Technology Noise Reduction Program. A 1/5-scale model simulator representing the bypass stage of a current technology high bypass ratio turbofan engine was used in the test. The test article consisted of the bypass fan and outlet guide vanes in a flight-type nacelle. The fan used was a medium pressure ratio design with 22 individual, wide chord blades. Three outlet guide vane design configurations were investigated, representing a 54-vane radial Baseline configuration, a 26-vane radial, wide chord Low Count configuration and a 26-vane, wide chord Low Noise configuration with 30° of aft sweep. The test was conducted in the NASA Glenn Research Center 9- by 15-Foot Low Speed Wind Tunnel at velocities simulating the takeoff and approach phases of the aircraft flight envelope. The Source Diagnostic Test had several acoustic and aerodynamic technical objectives: first, establish the performance of a scale model fan selected to represent the current technology turbofan product; second, assess the performance of the fan stage with each of the three distinct outlet guide vane designs; third, determine the effect of the outlet guide vane configuration on the fan baseline performance; and finally, conduct detailed flowfield diagnostic surveys, both acoustic and aerodynamic, to characterize and

14 citations

Proceedings ArticleDOI
18 Aug 2008
TL;DR: In this article, a comparison between an experimental study and a CFD analysis of the flowfield of an aggressive intermediate turbine duct for design inlet conditions is presented, highlighting some of the challenges associated with more aggressive intermediate ducts for the next generation of turbofan engines.
Abstract: Demands on lower emissions and reduced noise levels drive the design of modern turbofan engines toward high by-pass ratios. The design of the intermediate turbine ducts, connecting the high- and low-pressure turbines, will become more important as the turbofan engine by-pass ratios are increased. In order to introduce more aggressive designs there is a need to understand the flow features of high aspect ratio and high diffusion ducts. This is part one of a two-part paper, presenting a comparison between an experimental study and a CFD analysis of the flowfield of an aggressive intermediate turbine duct for design inlet conditions. Part one focuses on the on-design conditions and the second part will focus on off-design conditions. The experimental study was performed in a large-scale, low-speed turbine facility. The work presented highlights some of the challenges associated with more aggressive intermediate ducts for the next generation of turbofan engines. The main flow features are successfully reproduced by the CFD, but there are discrepancies found in the predicted local velocity and loss levels. An explanation of the discrepancies between the experimental data and the CFD results is provided and an attempt to track the origin of these differences is made.

14 citations

Proceedings ArticleDOI
28 Jul 2014
TL;DR: In this paper, a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data is presented, which analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes.
Abstract: This paper presents a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data. The technique analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes. Diagnostic results from the application of the approach to test data acquired from an aircraft turbofan engine are presented. The approach is found to avoid false alarms when presented nominal fault-free data. Additionally, the approach is found to successfully detect and isolate gas path seeded-faults under steady-state operating scenarios although some fault misclassifications are noted during engine transients. Recommendations for follow-on maturation and evaluation of the technique are also presented.

14 citations

Journal ArticleDOI
TL;DR: In this paper, the signie cancement of propulsion system steady-state performance prediction has been identie ed using digital simulation techniques with component maps and a controller, and the application of a simulation code has been demonstrated to an engine cycle redesigning case study without major modie cations in already existing hardware.
Abstract: The signie cance of propulsion system steady-state performance prediction has been identie ed. The digital simulation techniques have been described for steady-state performance prediction, with component maps and a controller. In addition to performance prediction, the application of a simulation code has been demonstrated to an engine cycle redesigning case study without major modie cations in already existing hardware. As per the current military application trends, the twin-spool turbofan with a mixed exhaust has been chosen as the propulsion concept. The proposed formulation can easily be modie ed to simulate the steady-state performance of the twin-spool turbojet engine and also to generate the control schedules in the early design stage. Nomenclature A = area ALT = altitude CD = nozzle e ow blockage factor Cp = specie c heat F = thrust g = gravitational constant H = enthalpy J = Joule’ s constant M = e ight Mach number N = rotational speed P = total pressure PR = nozzle pressure ratio p = static pressure R = gas constant T = total temperature t = static temperature V = e ow velocity W = mass e ow rate D = change in quantity g = ratio of specie c heats h = component efe ciency u = nozzle petal angle Subscripts

14 citations


Network Information
Related Topics (5)
Turbine
106.6K papers, 1M citations
74% related
Nozzle
158.6K papers, 893K citations
73% related
Reynolds number
68.4K papers, 1.6M citations
72% related
Internal combustion engine
130.5K papers, 1M citations
72% related
Piston
176.1K papers, 825.4K citations
71% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023163
2022320
2021112
2020131
2019175
2018189