Investigation of in-cylinder flow patterns in 4 valve S. I. Engine by using single-frame particle tracking velocimetry

Abstract

The in-cylinder flow field of gasoline engine comprises unsteady compressible turbulent flows caused by the intake port, combustion chamber geometry. Thus, the quantitative analysis of the in-cylinder flow characteristics plays an important role in the improvement of engine performances and the reduction of exhaust emission. In order to obtain the quantitative analysis of the in-cylinder gas flows for a gasoline engine, the single-frame particle tracking velocimetry was developed, which is designed to measure 2-dimensional gas flow field. In this paper, influences of the swirl and tumble intensifying valves on the in-cylinder flow characteristics under the various intake flow conditions were investigated by using this PTV method. Based on the results of experiment, the generation process of swirl and tumble flow in a cylinder during intake stroke was clarified. Its effect on the tumble ratio at the end of compression stroke was also investigated.

Effects of tumble and swirl flows on turbulence scale near top dead centre in a four-valve spark ignition engine

“…The processes for obtaining the velocity vector by using the PTV consist of the original image, ltering and thresholding, boundary detection and calculation of the centroid. A detailed description of these processes was given in previous work [6 ].…”

Numerical Simulation of Gas Flow in a Gasoline Engine Under Different Valve Lifts

“…The shapes of intake port and the gas flow characteristic in the engine cylinder have influenced the improvement of fuel-air mixing, combustion process, and the reduction of exhaust emissions [1] .The gas flow characteristic in the engine cylinder depends on the gas flow in the intake ports. The gas flow in the intake ports and cylinder is 3-dimensional, non-steady, compressible gas flow with heat transfer and friction, so it is difficult to study the flow situation in the intake ports and in the cylinder by experiments.…”

Numerical analysis of non-linear vibrations of a fractionally damped cylindrical shell under the conditions of combinational internal resonance

“…Shell elements are in pipes and ducts, bodies of cars, space shuttles, aircraft fuselages, ship hulls, submarines and building structures. Recent investigations on dynamic response of cylindrical shells are based on nonlinear theories [1][2][3][4][5], and a comprehensive review could be found in [6,7].…”