scholarly journals Laser Doppler Measurement of Local Flow Field in Collapsible Tube during Self-Excited Oscillation.

1997 ◽  
Vol 63 (607) ◽  
pp. 668-673 ◽  
Author(s):  
Kenkichi OHBA ◽  
Atsushi SAKURAI ◽  
Junji OKA
Keyword(s):  
Flow Field ◽  
Laser Doppler ◽  
Collapsible Tube ◽  
Doppler Measurement ◽  
Local Flow ◽  
Excited Oscillation

A Laser-Doppler Investigation of the Flow inside a Backswept, Closed, Centrifugal Impeller

1979 ◽  
Vol 21 (1) ◽  
pp. 1-6 ◽  
Author(s):  
D. Adler ◽  
Y. Levy
Keyword(s):  
Flow Field ◽  
Flow Fields ◽  
Fundamental Difference ◽  
Laser Doppler ◽  
Centrifugal Impeller ◽  
Doppler Technique

A laser-Doppler technique is successfully applied to measure the flow field inside a closed, backswept impeller, through a rotating window. Results show that, in contrast to the flow in many radial-exit impellers, the flow in the backswept impeller is stable and attached. Further, comparison with an open impeller demonstrates the fundamental difference in the flow fields near the shroud.

Integrated Microcomputer-LDV Instrumentation for Studying Finite Wing Aerodynamics

1993 ◽  
Author(s):  
Abdollah Khodadoust
Keyword(s):  
Reynolds Number ◽  
Flow Field ◽  
Data Acquisition ◽  
Fiber Optic ◽  
Three Dimensional ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Ice Accretion ◽  
Wing Model ◽  
Finite Wing

Abstract The effect of a simulated glaze ice accretion on the flow field of a three-dimensional wing is studied experimentally. A PC-based data acquisition and reduction system was used with a four-beam two-color fiber-optic laser Doppler velocimeter (LDV) to map the flow field along three spanwise cuts on the model. Results of the LDV measurements on the upper surface of the finite wing model without the simulated glaze ice accretion are presented for α = 0 degrees at Reynolds number of 1.5 million. Measurements on the centerline of the clean model compared favorably with theory.

Laser Doppler measurement of retinal blood velocity: validity of the single scattering model

1985 ◽  
Vol 24 (5) ◽  
pp. 605 ◽  
Author(s):  
Charles E. Riva ◽  
Juan E. Grunwald ◽  
Benno L. Petrig
Keyword(s):  
Single Scattering ◽  
Blood Velocity ◽  
Laser Doppler ◽  
Doppler Measurement ◽  
Scattering Model

Laser-Doppler Measurement of the Effects of Halothane and Isoflurane on the Cerebrovascular CO2 Response in the Rat

1995 ◽  
Vol 80 (4) ◽  
pp. 696-702
Author(s):  
Joseph G. Lee ◽  
Jeremy J. Smith ◽  
Antal G. Hudetz ◽  
Cecilia J. Hillard ◽  
Zeljko J. Bosnjak ◽  
...  
Keyword(s):  
Laser Doppler ◽  
Doppler Measurement ◽  
Co2 Response

scholarly journals Effect of Initial Axial Strain of Collapsible Tube on Self-Excited Oscillation.

1999 ◽  
Vol 65 (638) ◽  
pp. 3352-3358 ◽  
Author(s):  
Yupeng XIA ◽  
Toshiyuki HAYASE ◽  
Satoru HAYASHI ◽  
Tsuyoshi HAMAYA
Keyword(s):  
Axial Strain ◽  
Collapsible Tube ◽  
Excited Oscillation

Analysis of Local Flow Structure and Global Compressor Performance During Rotating Stall

2004 ◽  
Author(s):  
Chiara Palomba
Keyword(s):  
Flow Field ◽  
Flow Structure ◽  
Rotational Speed ◽  
Axial Flow ◽  
Rotating Stall ◽  
Performance Parameters ◽  
Flow Conditions ◽  
Local Flow ◽  
Flow Parameters ◽  
Compressor Performance

Rotating stall is an instability phenomenon that arises in axial flow compressors when the flow is reduced at constant rotational speed. It is characterised by the onset of rotating perturbations in the flow field accompanied by either an abrupt or gradual decrease of performances. Although the flow field is unsteady and non axisymmetric, the global operating point is stable and a stalled branch of performance curve may be experimentally determined. The number, rotational speed, circumferential extension of the rotating perturbed flow regions named rotating cells may vary from one compressor to another and may depend on the throttle position. The present work focuses on the interaction between local flow parameters and global compressor performance parameters with the aim of reaching a better understanding of the phenomenon. Starting from the Day, Greitzer and Cumpsty [1] model the detailed flow conditions during rotating stall are studied and related to the global performance parameters. This is done both to verify if the compressor under examination fits to the model and if the detailed flow structure may highlight the physics that in the simple model may hide behind the correlation’s used.

Experimental Investigations of Clocking in a One and a Half Stage Transonic Turbine Using Laser-Doppler-Velocimetry and a Fast Response Aerodynamic Pressure Probe

2006 ◽  
Author(s):  
O. Schennach ◽  
J. Woisetschla¨ger ◽  
A. Fuchs ◽  
E. Go¨ttlich ◽  
A. Marn ◽  
...  
Keyword(s):  
Flow Field ◽  
Laser Doppler Velocimetry ◽  
Fast Response ◽  
Laser Doppler ◽  
Experimental Investigations ◽  
Pressure Probe ◽  
Doppler Velocimetry ◽  
Flow Angle ◽  
Aerodynamic Pressure ◽  
Transonic Turbine

The current paper presents experimental clocking investigations of the flow field in midspan in a high-pressure transonic turbine with a downstream vane row (1.5 stage machine). Laser-Doppler-Velocimetry measurements were carried out in order to record rotor phase resolved velocity, flow angle and turbulence distributions upstream and downstream of the second vane row at several different vane-vane positions. Additionally, a fast response aerodynamic pressure probe was used to get the total pressure distribution downstream of the second vane row for the same positions. Altogether, the measurements were performed for ten different 1st vane to 2nd vane positions (clocking positions) for measurements downstream of the 2nd vane row and two different clocking positions for measurements upstream of the 2nd vane row. The paper shows that different clocking positions have a significant influence on the flow field downstream of the 2nd vane row. Furthermore different measurement lines upstream of the 2nd vane row indicate that clocking has nearly no influence on the flow field close to the rotor exit.

Sign in / Sign up

Export Citation Format

Share Document