Product Code: JLA_3_1_36

Authors:
Larry P. Goss
Michael E. Post
Darryl D. Trump
Benjamin Sarka
Systems Research Laboratories, Inc., A Division of Arvin/Calspan, 2800 Indian Ripple Road, Dayton, OH 45440‐3696 U.S.A.

A novel experimental method for determining two‐dimensional velocity flowfields has been developed. The technique, two‐color particle‐imaging velocimetry (PIV), is similar to existing PIV techniques except that two different‐color laser sources are used to form the light sheets required for exposing the position of particles in a seeded flowfield. A green‐colored laser sheet (formed by a doubled Nd:YAG laser) and a red‐colored laser sheet (formed by an Nd.YAG‐pumped dye laser) are employed sequentially to expose the particle positions, which are recorded on 35 mm color film. Analysis of the resulting images involves digitizing the exposed film with color filters to separate the green‐ and red‐particle image fields and processing the digitized images with velocity‐displacement software. The two‐color PIV technique has the advantage that direction, as well as particle displacement, is uniquely determined because the green‐particle image occurs before the red one by a known time increment. Velocity measurements utilizing the two‐color PIV technique on a propane jet diffusion flame have been made and are discussed.