Return to Research Areas

Planar Doppler Velocimetry

Introduction

 

Construction of a flow map using point measurement techniques, such as laser Doppler Velocimetry requires measurements to be made sequentially over an array of positions with the flow. The large amount of time involved makes such measurements costly. Flow mapping can be performed more efficiently using the recently developed technique of Planar Doppler Velocimetry (PDV). PDV is also known as Doppler Global Velocimetry (DGV) and is a planar imaging technique capable of measuring an array of flow vectors within an area defined by the plane of a laser light sheet. The spatial resolution of the measurement is a function mostly of the imaging optics used to image the light sheet.

 

Theory

3d Velocity measurements using imaging fibre bundles

Optimisation of viewing configurations for 3d-PDV systems

Two-frequency Planar Doppler Velocimetry (2n-PDV)

Mach-Zehnder interferometric Planar Doppler Velocimetry (MZI-PDV)

 

Researchers

Dr Tom O.H. Charrett

Dr Helen D. Ford

Prof. Ralph P. Tatam

 

Selected Publications

Mach-Zehnder interferometric filter based planar Doppler velocimetry (MZI-PDV)
Z-H Lu, T O H Charrett, H D Ford and R P Tatam
Journal of Optics A: Pure and Applied Optics 9, 1002-1013 (2007)

 

Investigation into the selection of viewing configurations for 3D Planar Doppler Velocimetry (PDV) measurements
T O H Charrett, D S Nobes and R P Tatam
Applied Optics 46, 4102-4116 (2007)
CERES: https://dspace.lib.cranfield.ac.uk/handle/1826/1831

 

Single camera three component planar velocity measurements using two frequency planar Doppler velocimetry
T O H Charrett and R P Tatam
Measurement Science and Technology, 17, 1194-1206 (2006) (Special Issue from OFS-17)
CERES: https://dspace.lib.cranfield.ac.uk/handle/1826/5464

 

Single camera 3D planar velocity measurements using imaging fibre bundles and two frequency Planar Doppler Velocimetry (2v-PDV)
T O Charrett, H D Ford, R P Tatam
Presented at the 17th Conference on Optical Fibre Sensors (OFS) May 23-27 2005, Bruges, Belgium
Proc SPIE 5855, 924-927 (2005)

 

Single camera three component planar velocity measurements, using two frequency Planar Doppler Velocimetry (2v-PDV)
T O H Charrett, H D Ford and R P Tatam
Presented at the conference Optical Diagnostics, part of SPIE's International Symposium on Optical Science and Technology, San Diego, USA, August 2005.
Published in SPIE Proc. 5880, 2005

 

Two-frequency planar Doppler velocimetry (2ν-PDV)
T Charrett, H D Ford, D S Nobes and R P Tatam
Review of Scientific Instruments, 75, 4487, 2004

 

Three component planar Doppler velocimetry using imaging fibre bundles
D S Nobes, H D Ford, and R P Tatam
Experiments in fluids 36, 3-10, 2004

CERES: https://dspace.lib.cranfield.ac.uk/handle/1826/1129

 

Determination of view vectors from image warping mapping functions
D S Nobes, B Wieneke and R P Tatam
Optical Engineering 43, 407-414, 2004

 

Planar Doppler Velocimetry
R P Tatam
Invited Paper Presented at the 12th Coherent Laser Radar Conference, Bar Harbor, Maine, USA, June 2003.
Published in the conference proceedings, 2003.

 

Dual illumination planar Doppler velocimetry using a single camera
T O H Charrett, H D Ford, D S Nobes, R P Tatam
Presented at the SPIE conference Optical Science and Technology, part of the SPIE's International Symposium on Optical Diagnostics for Fluids, Solids, and Combustion II, San Diego, USA, August 2003.
Presented in the proceedings, 5191, 2003.

 

Planar Doppler velocimetry measurements of flows using imaging fiber bundles
D S Nobes, H D Ford, R P Tatam
Presented at the SPIE conference Optical Science and Technology, part of the SPIE's International Symposium on Optical Diagnostics for Fluids, Solids, and Combustion II, San Diego, USA, August 2003.
Presented in the proceedings, 5191, 2003.

 

Imaging fibre bundle based 3D planar Doppler velocimetry
D S Nobes and R P Tatam
Presented at the 16th International Conference on Optical Fibre Sensors (OFS-16), Nara, Japan, October, 2003.
Published in the proceedings, IEICE, pp60-63, 2003

 

Three component planar Doppler velocimetry measurement using imaging fibre bundles
D S Nobes and R P Tatam
Presented at the Rank Prize Fund Mini-symposium on Optics in Fluid Dynamics, Grasmere, UK, August, 2002.

 

Acousto-optic frequency switching for single camera planar Doppler velocimetry
H D Ford, D S Nobes, and R P Tatam
Presented at the SPIE conference Optical Diagnostics for Fluids, Solids, and Combustion , San Diego, USA, 2001.
Proc. SPIE 4448, 272-282, 2001.

 

Instantaneous, two-camera, three dimensional planar Doppler velocimetry using imaging fibre bundles
D S Nobes, H D Ford, and R P Tatam
Presented at the SPIE conference Optical Diagnostics for Fluids, Solids, and Combustion , San Diego, USA, 2001. Proc.SPIE 4448, 283-294, 2001.

 

Development of extended field Doppler velocimetry for Turbomachinery Applications
H D Ford and R P Tatam
Optics and Lasers in Engineering, Special Issue on Optical Flow Measurement: Recent Advances and Applications , 27 , No. 6, pp 675-696, 1997.

 

Imaging system considerations in Doppler global velocimetry
H D Ford and R P Tatam
Presented at the International Symposium on Optical Diagnostics in Fluid, Thermal and Combustion Flow San Diego, USA, 1995.
Published in SPIE Proc .2546, pp 454-464, 1995.

 

PDV Theory

The concept of the PDV technique is very simple. Light scattered by particles seeded in the flow is Doppler shifted in frequency. The magnitude of the shift is dependent on both the propagating direction of the laser and the viewing of the region under investigation. The velocity of the particle is associated to the Doppler …

Bundles

3D velocity measurements using imaging fibre bundles   3D velocity measurements Using a single observation direction can measure a single component of velocity given by the vector (ô - î). Therefore to measure multiple components of the velocity requires multiple observation, or illumination directions. Single observation direction - multiple light sheets – Multiple velocity components …

3D Velocity

Optimisation of viewing configurations for 3d-PDV systems   Introduction It is not possible to measure directly the three orthogonal components of velocity, as there is no practical arrangement of three views, using a single light sheet, where the sensitivity vectors are orthogonal. Therefore, the three measured velocity components must be transformed from the measurement coordinate …

2nu PDV

Two-Frequency Planar Doppler Velocimetry (2-PDV) Theory Two-Frequency PDV is a modified PDV technique that reduces the equipment needed to a single camera and iodine cell to measure all three components of the velocity. In the 2-PDV technique the signal and reference images are acquired sequentially, on the same CCD camera by using two illumination frequencies. …

Interferometric PDV

Mach Zehnder interferometric planar Doppler velocimetry (MZI-PDV) Introduction PDV requires some form of filter to act as a frequency-to-intensity transducer; usually this is a molecular absorption cell, typically Iodine vapour; however an interferometric filter can potentially be used in a PDV system. This has several advantages, the choice of laser source is now not limited …