Laser Doppler Anemometry (LDA)

Laser Doppler Anemometry (LDA) or Laser Doppler Velocimetry (LDV)

Laser Doppler Anemometry (LDA), also known as Laser Doppler Velocimetry (LDV), is an optical technique ideal for non-intrusive 1D, 2D, and 3D point measurement of velocity and turbulence distribution in both free flows and internal flows.

Laser Doppler Velocimeters have several strong features:

  • Non-intrusive
  • Measure velocity components directly
  • Good spatial resolution (down to <1 mm)
  • Good temporal resolution (up to >1 kHz)
  • Wide velocity range (0 to hypersonic)
  • Measure the sign of the velocity in reversing flows.
  • Linear response to velocity
  • Calibration given by the laser wavelength and the intersection angle between the beams.

Researchers in science and industry use our Laser Doppler Anemometry (LDA) system to gain a clearer understanding of fluid mechanics. The measurement results are important steps in fine-tuning product designs to improve aerodynamic efficiency, quality, and safety.

The signal processor is a very important part of a Laser Doppler Velocimeter: in challenging applications, the Signal-to-Noise Ratio (SNR) is often low, so the processor must robustly extract the signal from seeding particles passing through the measurement volume (bursts), and determine their frequency which is proportional to the velocity, whilst rejecting false signals from noise. The Burst Spectrum Analyzer (BSA) is the market-leading LDV processor with a proven track record.

We have several thousand Laser Doppler Velocimeter systems installed worldwide, used in very diverse applications ranging from bio-fluid mechanics to rocket science. Most LDV systems are installed on water channels or wind tunnels, and they are used both for education and for fundamental or applied research as well as for optimization of aerodynamic or hydrodynamic performance of vehicles, airplanes, ships, pumps, turbines, combustion engines, and many others.

Laser Doppler Anemometer Solutions

 

FlexLDA

The FlexLDA system is a full-featured turnkey solution for working distances up to 500 mm and velocities up to 68 m/s.
 

FlowExplorer

FlowExplorer is a prealigned and calibrated LDA solution ideal for turbulence studies
 

FiberFlow

FiberFlow is a highly flexible solution for non-intrusive measurements of velocity at a point in space as a function of time
 

Integrated 3D LDA

Streamlined 3D LDA optics for wind tunnels and water channels
 

Mixed-brand LDV Solutions

Mixed-brand LDV Systems If you have an unsupported LDV system, we can help.

Features & Benefits

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Application Notes

Dust Transport on Mars

Dust Transport on Mars

Simulation of the wind driven transport of dust and sand on Mars measured by a Dantec 2D LDA…
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Velocity Measurements in Hydrogen Flames using LDA and PIV

Velocity Measurements in Hydrogen Flames using LDA and PIV

The transition from the use of hydrocarbons to alternative fuels such as hydrogen is expected to be a…
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Windshield velocity distribution measurements using low powered 2D FlowLite

Windshield velocity distribution measurements using low powered 2D FlowLite

In the automotive industry, customer clinics and surveys have revealed the importance to the customer of good demist/defrost…
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Velocity Measurements in Transonic Turbomachinery Blade Cascade Flow

Velocity Measurements in Transonic Turbomachinery Blade Cascade Flow

Increasing turbine inlet temperature, evolved for efficiency improvement, has resulted in a need for full-coverage film cooling for…
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3D LDA Measurements of a Jet in Crossflow on an Effusion-Cooled Plate

3D LDA Measurements of a Jet in Crossflow on an Effusion-Cooled Plate

There is a general desire to decrease the specific fuel consumption and to increase the thrust/weight ratio of…
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LDA measurements on wing/engine section of an Airbus A380

LDA measurements on wing/engine section of an Airbus A380

Aircraft manufacturers are especially interested in reducing aircraft drag in order to reduce fuel consumption and optimize engine…
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Download Library

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AUTHOR(S)

R. Theunissen, P. Gjelstrup

YEAR

2018

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AUTHOR(S)

Sophie Herpin, Laurent Perret, Romain Mathis, Christian Tanguy, Jean-Jacques Lasserre

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2018

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AUTHOR(S)

Palle Gjelstrup

YEAR

2009

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P. Gjelstrup, H. Nobach, F.E. Jørgensen, K. E. Meyer

YEAR

2000

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