Steady Flow Field Measurements Using Laser Doppler Velocimetry

Steady Flow Field Measurements Using Laser Doppler Velocimetry PDF Author: Ricky E. Wilson
Publisher:
ISBN:
Category :
Languages : en
Pages : 52

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Book Description
A computer-integrated LDV system utilizing a Helium-Neon laser was designed, assembled and tested for use in the study of steady flow field quantities. All system elements were integrated to include a traverse mechanism, signal processing and conditioning, computer interface and display. The system was initially calibrated utilizing a rotating wheel of known velocity. Experimental flow measurement tests of the system were conducted across a conventional free jet flow and in the Naval Postgraduate School low speed wind tunnel. The flow field velocity measurements made in the wind tunnel were verified usin an existing pressure data acquisition station and a standard pitot static probe. Keywords: Laser doppler velocimetry.

Steady Flow Field Measurements Using Laser Doppler Velocimetry

Steady Flow Field Measurements Using Laser Doppler Velocimetry PDF Author: Ricky E. Wilson
Publisher:
ISBN:
Category :
Languages : en
Pages : 52

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Book Description
A computer-integrated LDV system utilizing a Helium-Neon laser was designed, assembled and tested for use in the study of steady flow field quantities. All system elements were integrated to include a traverse mechanism, signal processing and conditioning, computer interface and display. The system was initially calibrated utilizing a rotating wheel of known velocity. Experimental flow measurement tests of the system were conducted across a conventional free jet flow and in the Naval Postgraduate School low speed wind tunnel. The flow field velocity measurements made in the wind tunnel were verified usin an existing pressure data acquisition station and a standard pitot static probe. Keywords: Laser doppler velocimetry.

Unsteady Flow Field Measurements Using LDV.

Unsteady Flow Field Measurements Using LDV. PDF Author: Steven Dale Hedrick
Publisher:
ISBN:
Category :
Languages : en
Pages : 73

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Book Description
The primary goal of this thesis was the development of an experimental technique, and supporting software, for the acquisition and analysis of unsteady velocity data generated by an oscillating airfoil. This research was in support of a major investigation of the compressibility effects on dynamic stall. The experimental procedure involved schlieren flow visualization for comparison of steady and unsteady flow fields, and for determination of parameters for further study. Laser Doppler velocimetry was employed for obtaining velocity data in the airfoil wake. For unsteady data, the airfoil was oscillated in pitch about its quarter chord. The data analysis produced wake profile plots representing the flow field distributed by the airfoil. Results were obtained for steady and unsteady conditions. Keywords: Laser doppler velocimetry, Schlieren flow visualization, Dynamic stall.

Steady and Unsteady Flow Field Measurements Within a NASA 22-Inch Fan Model

Steady and Unsteady Flow Field Measurements Within a NASA 22-Inch Fan Model PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 38

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Book Description


The Development of a Laser Doppler Velocimetry System for Unsteady Separated Flow Research

The Development of a Laser Doppler Velocimetry System for Unsteady Separated Flow Research PDF Author: R. A. Kadlec
Publisher:
ISBN:
Category : Laser Doppler velocimeter
Languages : en
Pages : 28

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Book Description
The Frank J. Seiler Research Laboratory (FJSRL) at the U.S. Air Force Academy is conducting a comprehensive experimental research program to study unsteady, separated flows and, in particular, the dynamic stall of oscillating airfoils. The aim of this study is to achieve a clearer understanding into the physical mechanisms responsible for dynamic stall and to capitalize on these unique stall features by using them to improve the turn performance and maneuverability of flight vehicles. The objective of one phase of this experimental research program has been to adapt a general purpose Laser Doppler VElocimetry (LDV) two velocity component system to dynamic stall experiments in the Subsonic Wind Tunnel at the USAFA. The preliminary design of the LDV system, its special constraints and the characterization of system signal and noise parameters are described. Results presented for the initial operation of the LDV system demonstrate its performance capabilities. It has been observed that accurate measurements in the wind tunnel environment can be achieved only when optical noise produced by scattered laser light from wind tunnel surfaces is minimized. While the LDV system configuration satisfies all constraints related to the USAFA Subsonic Wind Tunnel geometry and is capable of accurate velocity measurements in the two-dimensional flow field surrounding an airfoil, a reconfiguration of the system is suggested to improve optical alignment procedures and overall system signal-to-noise ratio. (Author).

The Use of the Laser Doppler Velocimeter for Flow Measurements

The Use of the Laser Doppler Velocimeter for Flow Measurements PDF Author: Warren H. Stevenson
Publisher:
ISBN:
Category : Fluid dynamic measurements
Languages : en
Pages : 580

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Book Description


Two Phase Flow Field Measurements in the Wake of a Bluff Body Using Laser Doppler Velocimetry

Two Phase Flow Field Measurements in the Wake of a Bluff Body Using Laser Doppler Velocimetry PDF Author: Eric Bachalo (University of Manitoba student)
Publisher:
ISBN:
Category :
Languages : en
Pages : 136

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Book Description


Laser Doppler and Phase Doppler Measurement Techniques

Laser Doppler and Phase Doppler Measurement Techniques PDF Author: H.-E. Albrecht
Publisher: Springer Science & Business Media
ISBN: 3662051656
Category : Science
Languages : en
Pages : 741

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Book Description
Providing the first comprehensive treatment, this book covers all aspects of the laser Doppler and phase Doppler measurement techniques, including light scattering from small particles, fundamental optics, system design, signal and data processing, tracer particle generation, and applications in single and two-phase flows. The book is intended as both a reference book for more experienced users as well as an instructional book for students. It provides ample material as a basis for a lecture course on the subject and represents one of the most comprehensive treatments of the phase Doppler technique to date. The book will serve as a valuable reference book in any fluid mechanics laboratory where the laser Doppler or phase Doppler techniques are used. This work reflects the authors' long practical experience in the development of the techniques and equipment, as the many examples confirm.

Application of Laser Doppler Velocimeter to Chemical Vapor Laser System

Application of Laser Doppler Velocimeter to Chemical Vapor Laser System PDF Author: Luther R. Gartrell
Publisher:
ISBN:
Category :
Languages : en
Pages : 28

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Book Description


Optical Measurements

Optical Measurements PDF Author: Franz Mayinger
Publisher: Springer Science & Business Media
ISBN: 3662029677
Category : Science
Languages : en
Pages : 462

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Book Description
Increasing possibilities of computer-aided data processing have caused a new revival of optical techniques in many areas of mechanical and chemical en gineering. Optical methods have a long tradition in heat and mass transfer and in fluid dynamics. Global experimental information is not sufficient for developing constitution equations to describe complicated phenomena in fluid dynamics or in transfer processes by a computer program . Furthermore, a detailed insight with high local and temporal resolution into the thermo-and fluiddynamic situations is necessary. Sets of equations for computer program in thermo dynamics and fluid dynamics usually consist of two types of formulations: a first one derived from the conservation laws for mass, energy and momentum, and a second one mathematically modelling transport processes like laminar or turbulent diffusion. For reliably predicting the heat transfer, for example, the velocity and temperature field in the boundary layer must be known, or a physically realistic and widely valid correlation describing the turbulence must be avail able. For a better understanding of combustion processes it is necessary to know the local concentration and temperature just ahead of the flame and in the ignition zone.

Three-Dimensional Velocity and Vorticity Measuring and Image Analysis Techniques

Three-Dimensional Velocity and Vorticity Measuring and Image Analysis Techniques PDF Author: Th. Dracos
Publisher: Springer Science & Business Media
ISBN: 9780792342564
Category : Science
Languages : en
Pages : 346

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Book Description
The contents of this volume reflect to a large extent the efforts made by a group of Institutes at the ETH Zürich to develop new techniques for measurements of flows in fluids in the last decade. The motivation came from the study of tr~sport and mixing processes in natural and industrial systems. One of the characteristic properties of turbulence is its high mixing efficiency. The techniques developed are therefore suitable, although not exclusively, for turbulence measurements. They can be subdivided into point-measurements and field-measurements. The aim of the point-measurements developed is to determine the three components of the velocity and all their first derivatives with good temporal resolution and accuracy in turbulent flows. The old and weIl established method of hot-wire anemometry was used for this purpose. One of the main achievements in this context is the construction of miniature multi-wire probes. This technique was introduced to the Institute of Hydromechanics and Water Resources Management of ETH Zürich by Profs. A. Tsinober and E. Kit from Tel-Aviv University. This was made possible by the generous financial support by ETH, for which I would like to express my gratitude on this occasion. In addition, Dr. F.E. Joergensen from DANTEC contributed an example of recent developments in the hardware ofConstant Temperature Anemometry (CTA), for which I am very thankful.