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Showing 1 to 14 of 14 for “"transonic fan"”.
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A numerical investigation of a flutter in a transonic fan
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1996.
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Modal Response of a Transonic Fan Blade to Periodic Inlet Pressure Distortion
… The first three modes of a low-aspect-ratio, transonic, first stage blade of a two-stage fan were examined. The generalized forcing function was decomposed to the frequency domain to identify the dominant harmonic magnitude present, as well as other contributing harmonics. An attempt to define …
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Measurement and Uncertainty Analysis of Transonic Fan Response to Total Pressure Inlet Distortion
Distortion tolerant fans represent the enabling technology for the successful implementation of highly integrated airframe propulsion system vehicles. This investigation extends the study of fan-distortion interactions to an actual turbofan engine with a total pressure distortion profile …
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Effects of Inlet Guide Vane Flow Control on Forced Response of a Transonic Fan
… was evaluated in a modern single-stage transonic compressor rig. A row of wake generator (WG) vanes with TEB capability was installed upstream of the fan blisk, the blades of which were instrumented with strain gages. Data was collected for varied TEB conditions over a range of rotor …
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Full Scale Experimental Transonic Fan Interaction with a Boundary Layer Ingesting Total Pressure Distortion
… would have on the behavior and performance of a transonic fan in a full scale engine test environment. This dissertation presents an experimental study of the interaction between a full scale transonic fan and a total pressure distortion representative of a boundary layer ingesting serpentine …
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Investigation of Inlet Guide Vane Wakes in a F109 Turbofan Engine with and without Flow Control
… of experiments were conducted in a F109 turbofan engine to investigate the unsteady wake profiles of an Inlet Guide Vane (IGV) at a typical spacing to the downstream fan at subsonic and transonic relative blade velocities. The sharp trailing-edge vanes were designed to produce a wake profile …
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The Influence of Development and Fan/Screen Interaction on Screen-Generated Total Pressure Distortion Profiles
The rising interest in fan performance in the presence of total pressure distortion, a topic of fundamental interest for integrated airframe/engine architectures, has led to increased research in ground based testing environments. Included in these studies is the generation of simulated total …
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Distortion Tolerant Fan Design
… a fuel burn reduction of up to 15%. However, the fans need to operate in severely distorted flow, which affects the blades’ mechanical integrity, aerodynamic efficiency and stability. The aim of this thesis is to understand the impact of strengthening rotor blades on aerodynamic performance, …
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A multidisciplinary algorithm for the 3-D design optimization of transonic axial compressor blades
… The process was applied to two different transonic fan designs - the Sanger rotor designed for the NPS Turbomachinery Laboratory and NASA Rotor 67, otherwise known as the 'NASA Fan'. The optimization objectives for the two designs were mass flow rate and polytropic efficiency respectively. …
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Shock oscillation mechanisms of highly separated transitional shock-wave/boundary-layer interactions
… result in a low chord Reynolds number on the transonic fan – the first bladed component at the engine inlet of the turbofan engine. Consequently, a laminar boundary layer persists on the suction side of the transonic fan during cruise. Additionally, the trend in compressor design is higher …
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Flutter and Forced Response of Turbomachinery with Frequency Mistuning and Aerodynamic Asymmetry
… presented in Chapter 2, the mechanisms of transonic fan flutter for tuned systems are studied to improve the shortcoming of traditional method for modern fans using a 3D time-linearized Navier-Stokes solver. Steady and unsteady flow parameters including local work on the blade surfaces are …
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Parametric dependencies of aeroengine flutter for flutter clearance applications
… flutter stability. Test data from a full-scale transonic fan, spanning the full 4D parameter space, were also analyzed. A novel boundary fitting tool was developed for data processing, which can handle the generic case of sparse, multidimensional, binary data. The results indicate that the inlet …
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Stall inception in high stage loading low pressure ratio transonic fans
… its engines. Reducing the pressure ratio of the fan system is one route through which fuel consumption can be reduced by increasing propulsive efficiency. However, reducing the fan total pressure ratio encourages a move to increase the stage loading, which can enable engine weight reduction. This …