A Study of Cycle-to-Cycle Flow Variations in a Small Spark-Ignition Engine at Low Throttle Opening 2018-32-0035
Cycle-to-cycle flow variations significantly influence the combustion variations from one cycle to the next, particularly at low operating loads in small spark-ignition engines. Hence in the present work, cycle-to-cycle flow variations are analyzed at low throttle opening in a small spark-ignition engine using particle image velocimetry (PIV) technique. Experiments are conducted in an optically accessible single-cylinder port-fuel-injection engine (volume: 110 cm3) at 1200 rpm with throttle opening of 25%. Images are captured at different crank angle positions during both intake and compression strokes over a tumble measurement plane bisecting the intake and exhaust valves, and processed using cross-correlation method to obtain the instantaneous velocity fields considering 200 image pairs at each crank angle position considered. Turbulent Kinetic energy and probability density functions of vorticity are then calculated from measured instantaneous velocity fields at different crank angle positions to quantify the cycle-to-cycle variations. CFD simulations are also performed using CONVERGE software, and showed good agreement with measured flow fields using PIV.
Gaurav Shinde, Mayank Mittal, V LakshmiNarasimhan
Indian Institute of Technology, Madras, R&D, TVS Motor Company, Hosur, India
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