Date of Award


Degree Name

Master of Science


Mechanical and Aerospace Engineering

First Advisor

Dr. Parviz Merati

Second Advisor

Dr. Richard Hathaway

Third Advisor

Dr. Iskender Sahin

Fourth Advisor

Dr. Jerry Hamelink

Access Setting

Masters Thesis-Open Access


The project was designed to measure a reciprocating engine fluid flow (blowby gases past the piston rings) using a laser doppler velocimeter (LDV). Blowby gases were obtained by introducing compressed air into an engine cylinder (piston held at TDC) to simulate engine combustion pressures. Beginning the proposed research included starting an LDV/reciprocating engine laboratory at Western Michigan University and determining the limits of the measurement devices (LDV system in particular).

The limitations which were found in the LDV system only allowed for limited results of in cylinder optical measurements. The results obtained were for cylinder pressures below 0.6 kPa gauge pressure. The blowby gases were therefore analyzed using hot film anemometry. Various piston ring gap orientations were measured to see how the relationship of ring end gap alignment affected the blowby gases. As expected when the ring end gaps were aligned the blowby gases were at a maximum and when they were located 120° apart the blowby gases were minimized.