Cycle-skipping strategies for pumping loss reduction in spark ignition engines: An experimental approach

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Yüksek L., Özener O., Sandalcı T.

ENERGY CONVERSION AND MANAGEMENT, vol.64, pp.320-327, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 64
  • Publication Date: 2012
  • Doi Number: 10.1016/j.enconman.2012.05.025
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.320-327
  • Keywords: Pumping loss, Spark ignition engine, Cycle-skipping, Partial loading, Gaseous emissions, VARIABLE STROKE-LENGTH, SI ENGINE, FUEL-ECONOMY, PERFORMANCE, SIMULATION, HYDROCARBONS, OPTIMIZATION, EMISSIONS
  • Yıldız Technical University Affiliated: Yes


Spark ignition (SI) engines are widely used for power generation, especially in the automotive industry. SI engines have a lower thermal efficiency than diesel engines due to a lower compression ratio, higher charge-induction work and lower end of compression stroke pressure. A significant amount of charge induction work is lost when an SI engine runs under partial loading conditions. Under partial loading conditions, a lower intake charge is required, which can be theoretically achieved by varying the displacement volume or the stroke number of the engine without using a throttle. Reducing the displacement volume to control the engine load can be achieved by skipping cycles in single-cylinder engines. This study investigates the effect of cycle-skipping strategies on the brake specific fuel consumption (BSFC) and exhaust emissions of an SI engine under partial loading conditions. Three different skipping modes were applied: normal, normal-skip and normal-normal-skip. A significant improvement in BSFC and carbon monoxide emission was obtained by applying cycle-skipping strategies. (C) 2012 Elsevier Ltd. All rights reserved.