Model based mapping of a novel prototype spark ignition opposed-piston engine

• Published in: Energy conversion and management Vol. 309; p. 118434
• Main Authors: Furze, S.F., Barraclough, S., Liu, D., Melendi-Espina, S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: Alternative fuels; Externally scavenged; Internal combustion engine; Opposed piston two stroke; Spark ignition; HCCI; SCR; EPO; GHG; MPRR; HRR; IDC; IPO; RNG; ODC; RANS; SI; PFP; Spark ignition; Opposed piston two stroke; AMR; CI; CAD; OP2S; ICE; GCI; IMEP; BEV; BTE; ECU; HEV; EPC; Internal combustion engine; LES; PCCI; Externally scavenged; IPC; MAP; Alternative fuels
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2024.118434

•Air-side surfaces of a novel, real prototype under construction were modelled.•A motored approach was used to predict the trapped in-cylinder air mass.•The resulting table will aid ECU programming for future testing of the prototype.•Targeted CH4-fuelled simulations served to test the table at different conditions.•Equivalence ratio was within 10 % of target value at 1500/3000 rpm, 120/150/180 kPa. Blower-scavenged opposed-piston two-stroke engines possess inherent thermodynamic advantages over four stroke engines. Increasingly well demonstrated in compression ignition form, they are less so in spark ignition form, where there is clearly room for further investigation. Using CONVERGE® CFD, in this work therefore the fuelling requirements of a novel and under-construction small-displacement, two-stroke, spark-ignition, blower-scavenged opposed-piston engine prototype were estimated using three-dimensional computational fluid dynamics simulations. Trapped air mass values generated from motored simulations were used to populate a fuel-agnostic table of speed/scavenge pressure conditions, which will significantly aid the configuration of the engine ECU. This table was tested using targeted fuelled simulations, based on bulk in-cylinder equivalence ratio. Results indicate it was able to predict the required fuel within ±2 % at 1500 rpm, 120/150/180 kPa and 3000 rpm, 150/180 kPa, within ±10 % at 3000 rpm, 120 kPa and 5000 rpm, 180 kPa, and within ±20 % at 5000 rpm, 150 kPa. It performed less well at 5000 rpm, 120 kPa where it overestimated the required fuel by over 43 %, although this was to be expected given the reduced scavenging performance at high speed, low scavenge pressure conditions. The swirl-imparting geometry also appeared to aid in flame front propagation.