Miniaturized 3-component Laser Doppler Velocimeter LDV-3D

This technique is used to measure the local flow velocities and turbulence values mainly when physical interference with the flow must be avoided. It is, therefore, particularly suitable, for instance, for the measurement of boundary layers on a car surface.

Moreover, the intrinsic characteristics of this technique (i.e. capablity of measuring unsteady  flows as well as  low velocities, down to 'zero'), together with the very small size of the end-probe, make this instrumentation particularly suitable to measure the flow under the bonnet, in the engine compartment. These measurements can be necessary  to understand local over-heating problems of electronic components installed under the bonnet or to validate the results of CFD simulations in the engine compartment.

Examples of these measurements are shown in the following figures.

[Laser - Copyright © 1990 Pininfarina]
[Laser measurements outside the vehicle - Copyright © 1987 Pininfarina]
[Velocity distribution behind a cooling fan - Copyright © 1990 Pininfarina]

References

  • [1] "Development and Use of LDV and Other Airflow Measurement Techniques as a Basis for the Improvement of Numerical Simulation of Engine Compartment Air Flows", H. Berneburg, A. Cogotti, SAE Congress Paper n° 930294. Detroit , March 1993
  • [2] "Engine Compartment Airflow Investigations Using a Laser-Doppler-Velocimeter", A. Cogotti, H. Berneburg, SAE Congress Paper n° 910308. Detroit, February-March 1991