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http://dx.doi.org/10.3795/KSME-B.2016.40.7.417

Effects of Port Shape on Steady Flow Characteristics in an SI Engine with Semi-Wedge Combustion Chamber (1) - Velocity Distribution (1)  

Kim, Hyeongsig (Graduate school of Energy & Environment, Seoul Nat'l Univ. of Science and Technology)
Ohm, Inyong (Department of Mechanical and automotive Engineering, Seoul Nat'l Univ. of Science and Technology)
Publication Information
Transactions of the Korean Society of Mechanical Engineers B / v.40, no.7, 2016 , pp. 417-427 More about this Journal
Abstract
This paper is the first investigation of the steady flow characteristics of an SI engine with a semi-wedge combustion chamber as a function of the port shape. For this purpose, the planar velocity profiles were measured at the 1.75B position by particle image velocimetry. The flow patterns were examined with both a straight and a helical port. Two swirls were observed up to 4 mm valve lift with the straight port and up to 2 mm with the helical one; however, only one swirl was present after these lifts. The flow characteristics changed suddenly between 4 and 5 mm lift in the straight port; on the other hand, the change with lift was gradual with the helical port - the transition points between flow regimes were different with the port shapes. In addition, the centers of the swirls were relatively far from the cylinder center so that the effect of eccentricity may not be negligible at 1.75B, regardless the shape. The eccentricity values with the straight port were especially high - over 0.5 for all lifts. Finally, real velocities were found to be much lower than those predicted by the assumption of ISM evaluation, with the profiles differing qualitatively as well.
Keywords
Steady Flow Bench; Semi-Wedge Combustion Chamber; Swirl; Impulse Swirl Meter; PIV; Velocity Profile; Eccentricity; Straight Port; Helical Port;
Citations & Related Records
Times Cited By KSCI : 5  (Citation Analysis)
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