FLOW-FIELD DIAGNOSTICS IN INDUSTRIAL-DEVICES

A new 2-dimensional time resolved (200 frames/s) flow field measuring technique (PIV-Movie) has been developed and applied to quantitative c ycle resolved measurements of the instationary flow field within the c ombustion chamber of a transparent square piston engine. A conventiona l Particle Image Velocimetry (PIV) setup was modified using a double p ulsed copper vapor laser (200 Hz, pulse separation 33 microseconds) an d a rotating drum camera, which was used to record the Mie-scattered s ignals from seeding particles. The circumferential velocity of the dru m of the camera causes an image shifting of the two exposures taken wi th a double pulse. Because the copper vapor laser can be run continuou sly in the double pulse mode a series of up to 70 double pulsed images per individual engine cycle could be recorded on photographic film. T hese film data were evaluated with respect to both magnitude and direc tion of individual flow vectors in the flow field.