Title: Effect of port gas injection on in-cylinder stratification in a CNG fuelled SI engine

Authors: Manish Garg; R.V. Ravikrishna

Addresses: Research and Development, TVS Motor Co., Ltd., Hosur 635 109 TN, India ' Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560 012, India

Abstract: The concept of barrel stratification of air-fuel mixture is evaluated for a port gas injection (PGI) single cylinder spark ignition (SI) internal combustion (IC) engine using a transient three-dimensional computational fluid dynamic (CFD) model. The gaseous fuel used in the study is compressed natural gas (CNG). It is observed that compared to the premixed gas carburettor case, a substantial amount of in-cylinder stratification can be achieved with port gas injection system. A detailed parametric study is reported to understand the effect of the various injection parameters such as injection location, injection orientation, start of injection (SOI) and its duration, and injection rate. Furthermore, the best injection timing is evaluated for various load and speed cases. It is observed that the best stratification pattern can be achieved at 50% engine load. The injection location is observed to have a profound effect on the in-cylinder stratification pattern, and injection towards the side of the spark plug is observed to give a rich fuel-air mixture near the spark plug. It is also shown that there exists an optimal injection pressure.

Keywords: internal combustion engines; compressed natural gas; CNG; computational fluid dynamics; CFD; air-fuel stratification; axial stratification; barrel stratification; port gas injection; PGI; spark ignition engines; SI engines; injection timing; injection parameters; injection pressure.

DOI: 10.1504/PCFD.2014.063865

Progress in Computational Fluid Dynamics, An International Journal, 2014 Vol.14 No.4, pp.244 - 258

Received: 08 May 2021
Accepted: 12 May 2021

Published online: 24 Jul 2014 *

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