Airflow Visualization and LDV Measurements in a Motored Rotary Engine Assembly Part 1: Flow Visualization

Flow visualization observations are described in a motored stratified charge rotary engine. Analysis of the flow field is presented for naturally aspirated and supercharged conditions at shaft speeds of 675 and 1170 rpm, during the intake and compression strokes. The entrained air through the induction system is seeded by using microballoon particles (40 μm in mean diameter). Light scattered off the particles is recorded by high speed camera at 5000 frames per second. The camera is equipped with an optical pickup and pulse generator to trigger the 40 watt copper vapor laser synchronously with the rotating prism camera. Major flow features identified include leakage past the apex seal, separation at the rotor pocket and a large recirculation region during intake. Also, the motion pictures demonstrated that the rotor motion has the controlling effect on the turbulent flow field during the intake-compression strokes.