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Laser Doppler anemometry measurements have been made in a motored rotary engine assembly. The purpose of this study was to compare the flow fields of two different rotor pocket geometries experimentally. Two-dimensional measurements were taken over a central plane grid during intake and early compression at a shaft speed of 2000 rpm and wide open throttle. This data is to be used to quantify the central plane flow field and to provide experimental data for comparison with current analytical models. Two rotor pocket geometries were examined. The first rotor pocket geometry was a leading deep recess, and the second was a centrally located symmetric pocket. The same production apex and side seals were used for both rotors. The reduced velocity data was displayed as vector field plots within a computer animation to facilitate observation of the flow field and comparisons to analytical models.

An experimental study of the blowby past the apex seals and its controlling effect on the flow field was conducted in a motored rotary engine. A high speed flow visualization technique and laser Doppler anemometry (LDA) measurements were applied to analyze the blowby past two--piece and three-piece engine apex seals under motored conditions of 2000 rpm crank shaft speed. A light sheet from a 40 watt pulsed copper vapor laser was synchronized with a high speed rotating prism camera to record light scattered off microballoon particles onto motion picture films photographed at 5000 frames per second. A sequence of photographs is selected from the films to demonstrate the blowby characteristics past the apex seals and their effect on the flow field during the intake and compression strokes. Detailed LDA velocity measurements using propylene glycol as seeding particles, 0.6 μm in diameter, are also presented to quantify the blowby past the apex seals.

The purpose of this work was to develop a high speed flow visualization system which could be used to observe the behavior of the air flow in a steady flow cylinder head assembly. This type of experimental rig has been used by engineers for many years to evaluate valve discharge coefficients. This study is believed to be the first high speed flow visualization of the air flow in a system of this type. Particular emphasis was placed on the characterization of intake generated swirl and tumble motions within the cylinder. A 40 watt copper vapor laser was used to expose motion picture films at 5000 frames per second. The light scattering medium was phenolic microballoons. Based on the flow visualization results, selected LDV measurements were made to quantify the visual observations. A propylene glycol aerosol was used for seeding in the LDV experiments.