Laser Anemometry | ScienceGate

Several flow phenomena, including flow field periodicity, rotor shock oscillation, and rotor shock system geometry have been investigated in a transonic low aspect ratio fan rotor using laser anemometry. Flow periodicity is found to increase with increasing rotor pressure rise and to correlate with blade geometry variations. Analysis of time-accurate laser anemometer data indicates that the rotor shock oscillates about its mean location with an amplitude of 3–4 percent of rotor chord. The shock surface is nearly two-dimensional for levels of rotor pressure rise at and above the peak efficiency level but becomes more complex for lower levels of pressure rise. Spanwise shock lean generates radial flows due to streamline deflection in the hub-to-shroud streamsurface.

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Design, Test and Analysis of a High-Pressure-Ratio Transonic Fan

Volume 6: Turbo Expo 2003, Parts A and B ◽

10.1115/gt2003-38302 ◽

2003 ◽

Cited By ~ 4

Author(s):

W. John Calvert ◽

Paul R. Emmerson ◽

Jon M. Moore

Keyword(s):

High Performance ◽

Mechanical Design ◽

Pressure Ratio ◽

Operating Conditions ◽

Pressure Transducers ◽

Technology Acquisition ◽

Laser Anemometry ◽

High Pressure Ratio ◽

Response Pressure ◽

Stage Matching

Aircraft gas turbine engines require compression systems with high performance and low weight and cost. There is therefore a continuing drive to increase compressor stage pressure ratios, particularly for military fans. To meet this need, a technology acquisition programme has been carried out by QinetiQ and Rolls-Royce. Firstly, the stage matching issues for an advanced two-stage military fan were investigated, including the effects of employing variable inlet guide vanes. From this, the requirements for the first stage together with key operating conditions for the blading were defined. The blade profiles were then designed to satisfy the range of aerodynamic conditions using a quasi-3D calculation system. A satisfactory compromise between the aerodynamic and mechanical design requirements was reached in which a blisk construction was employed for the rotor, machined from a single piece of titanium. The new stage was manufactured and tested successfully, and it achieved its target flow, pressure ratio and efficiency on the first build. Detailed measurements of the internal flows using laser anemometry and high response pressure transducers were taken. Finally, these data have been analysed and used to calibrate current 3D multi-row CFD methods.

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Model of non-standar measurement flow by laser anemometry

17th Congress of the International Commission for Optics: Optics for Science and New Technology ◽

10.1117/12.2316238 ◽

1996 ◽

Author(s):

Miroslav Hrabovský

Keyword(s):

Laser Anemometry

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Measurement of Tip-Clearance Flow in a Multi-Stage, Axial Flow Compressor

Volume 1: Turbomachinery ◽

10.1115/94-gt-431 ◽

1994 ◽

Author(s):

Andrew C. Foley ◽

Paul C. Ivey

Keyword(s):

Large Scale ◽

Static Pressure ◽

Axial Flow ◽

Tip Clearance ◽

Suction Surface ◽

Tip Clearance Flow ◽

Laser Anemometry ◽

Two Dimensional Flow ◽

Inlet Conditions ◽

Stators And Rotors

Detailed measurements using pneumatic probe traverses, blade static pressure tappings and laser anemometry are made in the third stage of a large scale, low speed, four stage, axial flow, research compressor. Inlet conditions show well ordered ‘two dimensional’ flow from approximately 40 to 85% annulus span. Outside of this region, reduced total pressure due to upstream leakage losses aod endwall effects results in high incidence to the following blade row. As a result, peak suction surface static pressure moves forward along the blade chord for both the huh and tip of stators and rotors. At the blade tip however, the peak suction pressure is maintained with chord due to radial flow on the suction surface being entrained into the tip leakage jet. The extent of rotor chord for which this ‘entrainment’ occurs increases with increasing rotor tip clearance gap. The leakage jet from both stators and rotors is seen to ‘roll up’ into a vortex downstream of their respective blade rows.

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