Closure to “Discussion of ‘Turbulent Flow Measurements by Laser-Doppler Anemometry in Motored Piston-Cylinder Assemblies’” (1980, ASME J. Fluids Eng., 102, p. 251)

1980 ◽  
Vol 102 (2) ◽  
pp. 251-251
Author(s):  
A. P. Morse ◽  
J. H. Whitelaw ◽  
M. Yianneskis
Keyword(s):  
Turbulent Flow ◽  
Laser Doppler Anemometry ◽  
Laser Doppler ◽  
Flow Measurements ◽  
Piston Cylinder

scholarly journals A spectral analysis of laser Doppler anemometry turbulent flow measurements in a ship air wake

2015 ◽  
Vol 229 (12) ◽  
pp. 2309-2320 ◽  
Author(s):  
R Bardera-Mora ◽  
MA Barcala-Montejano ◽  
A Rodríguez-Sevillano ◽  
G González de Diego ◽  
M Ruiz de Sotto
Keyword(s):  
Spectral Analysis ◽  
Turbulent Flow ◽  
Laser Doppler Anemometry ◽  
Laser Doppler ◽  
Flow Measurements

Turbulent Flow Measurements by Laser-Doppler Anemometry in Motored Piston-Cylinder Assemblies

1979 ◽  
Vol 101 (2) ◽  
pp. 208-216 ◽  
Author(s):  
A. P. Morse ◽  
J. H. Whitelaw ◽  
M. Yianneskis
Keyword(s):  
Cylinder Head ◽  
Laser Doppler Anemometry ◽  
Laser Doppler ◽  
Cylinder Wall ◽  
Mean Velocity ◽  
Flow Measurements ◽  
Piston Bowl ◽  
Piston Cylinder ◽  
Large Vortex ◽  
Strong Vortex

Laser-Doppler anemometry has been used to quantify the mean velocity and turbulence characteristics of the isothermal, incompressible flow within a piston-cylinder arrangement motored without compression at 200 rpm and with idealized inlet geometries corresponding to a pipe and to an annular port located in the centre of the cylinder head. The results indicate that the pipe entry gives rise to a strong vortex near the piston as the indrawn air is deflected radially along the piston face and cylinder wall; this, in turn, gives rise to a weaker, counter-rotating vortex near the cylinder head which grows appreciably as the piston approaches bottom-dead-centre. With the annular-port entry, the inlet jet is angled and results in a flow pattern with a large vortex occupying nearly all of the flow space with much smaller vortices at the corners between the wall and the piston and cylinder heads. The effect of a piston bowl was also investigated for the port entry and is shown to be small.

scholarly journals A Rotating Laser-Doppler Anemometry System for Unsteady Relative Flow Measurements in Model Centrifugal Impellers

1993 ◽  
Author(s):  
M. Abramian ◽  
J. H. G. Howard
Keyword(s):  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Rotating Stall ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Laser Doppler ◽  
Low Flow ◽  
Centrifugal Impeller ◽  
Flow Measurements ◽  
Relative Flow

The behaviour of the relative flow in centrifugal turbomachines is extremely complex due to the existence of various fluid dynamic phenomena and their interaction. At design and off-design operating conditions, the relative flow is subject to stationary unsteadiness which includes the flow separation and wakes associated with passage pressure gradients, secondary flows, and boundary layer stability. It is also subject to periodic unsteadiness from the rotating stall and the cyclic flow phenomena induced by the casing. This paper describes the mechanical and optical design of a rotating laser-Doppler anemometry system which allows direct measurement of the relative flow by means of an optical de-rotator. By isolating the impeller rotational frequency from the sampling frequency, it allows direct time-average measurements of the stationary behaviour of the relative flow along with the ensemble (phase)-average measurements of its periodic behaviour. Its success is demonstrated with measurements conducted in a low specific speed centrifugal impeller fitted with a single volute. Sample results of the time-averaged blade-to-blade variation of total relative velocities along with their associated turbulence intensities are reported. The (periodic) cyclic variations of the impeller exit flow, induced by the volute at low flow rates, are also presented for the suction and pressure sides.

A Rotating Laser-Doppler Anemometry System for Unsteady Relative Flow Measurements in Model Centrifugal Impellers

1994 ◽  
Vol 116 (2) ◽  
pp. 260-268 ◽  
Author(s):  
M. Abramian ◽  
J. H. G. Howard
Keyword(s):  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Rotating Stall ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Laser Doppler ◽  
Low Flow ◽  
Centrifugal Impeller ◽  
Flow Measurements ◽  
Relative Flow

The behavior of the relative flow in centrifugal turbomachines is extremely complex due to the existence of various fluid dynamic phenomena and their interaction. At design and off-design operating conditions, the relative flow is subject to stationary unsteadiness, which includes the flow separation and wakes associated with passage pressure gradients, secondary flows, and boundary layer stability. It is also subject to periodic unsteadiness from the rotating stall and the cyclic flow phenomena induced by the casing. This paper describes the mechanical and optical design of a rotating laser-Doppler anemometry system, which allows direct measurement of the relative flow by means of an optical derotator. By isolating the impeller rotational frequency from the sampling frequency, it allows direct time-averaged measurements of the stationary behavior of the relative flow along with the ensemble (phase)-averaged measurements of its periodic behavior. Its success is demonstrated with measurements conducted in a low specific speed centrifugal impeller fitted with a single volute. Sample results of the time-averaged blade-to-blade variation of total relative velocities along with their associated turbulence intensities are reported. The (periodic) cyclic variations of the impeller exit flow, induced by the volute at low flow rates, are also presented for the suction and pressure sides.

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