A review of design considerations for light-duty diesel combustion systems

Abstract

Practical aspects of light-duty diesel combustion system design are reviewed, with an emphasis on design considerations reported by manufacturers and engine design consultancies. The factors driving the selection of compression ratio, stroke-to-bore ratio, and various aspects of combustion chamber geometry are examined, along with the trends observed in these parameters in recently released engines. The interactions among geometric characteristics, swirl ratio, and the fuel injection nozzle parameters are also reviewed.

Analysis of the effect of bore/stroke ratio and scavenge port angles on the scavenging process in a two-stroke boosted uniflow scavenged direct injection gasoline engine

“…race car engines, 12,13 a large B/S ratio is adopted due to slower piston speed and lower friction loss, adapting to the higher loads and engine speeds. 11,14 The larger bore can also accommodate larger intake/exhaust valves to improve the gas exchange for higher loads and engine speeds. 11 For those engines that require high fuel efficiency, e.g.…”

“…11,14 The larger bore can also accommodate larger intake/exhaust valves to improve the gas exchange for higher loads and engine speeds. 11 For those engines that require high fuel efficiency, e.g. heavy-duty engines and marine engines, 15 a small B/S ratio is adopted.…”

“…As a result, a small B/S ratio design usually shows higher combustion efficiency and thermal efficiency. 8,9,11,[16][17][18][19][20] However, as the engine speed increases, the advantage of long stroke would be gradually lost as the friction loss significantly increases. 8 It is also reported that the reduced convection heat losses at part load could compensate the unfavorable surface/volume ratio for a ''square'' design with B/S ratio of 1, resulting in fuel consumption benefits by improving the reciprocating and rotating components stress and friction at high speed.…”

12th International Congress of Engine Combustion Processes: Current problems and modern techniques (ENCOM2015)

“…1 The first three review papers mentioned are also included in this Special Issue. [2][3][4] This Special Issue is a selection of 13 papers presented at the ENCOM congress covering several different aspects within the broad range of engine combustion. Only those papers have been selected and submitted for peer review in the International Journal of Engine Research which promise to provide new information in the field or which own at least in some aspects a review-like character.…”

Thermo- and Fluid-Dynamic Processes in Direct Injection Engines: THIESEL 2016 Special Issue

“…People familiar with this conference will know that its topics include all thermo-and fluid-dynamic processes affecting the engine, ranging from the intake and injection systems to novel combustion concepts and to the turbo-charging and after-treatment technologies. 1 Progress on injection strategies and understanding of mixture formation -which is key to combustion improvement and emissions control 2,3 -relies nowadays strongly on modelling performance, especially as modern computer technology allows for serious cost reduction. Hence, much effort is put on the development of reliable spray and combustion models that include detailed kinetics and better turbulence models.…”