Spray combustion simulation study of waste cooking oil biodiesel and diesel under direct injection diesel engine conditions
Type
ArticleKAUST Department
Chemical Engineering ProgramClean Combustion Research Center
Combustion and Pyrolysis Chemistry (CPC) Group
Physical Science and Engineering (PSE) Division
Date
2020-02-06Online Publication Date
2020-02-06Print Publication Date
2020-05Embargo End Date
2022-02-06Submitted Date
2019-07-30Permanent link to this record
http://hdl.handle.net/10754/661545
Metadata
Show full item recordAbstract
Spray combustion characteristics of waste cooking oil biodiesel (WCO) and conventional diesel fuels were simulated using a RANS (Reynolds Averaged Navier Stokes) based model. Surrogates were used to represent WCO and diesel fuels in simulations. N-tetradecane (C14H30) and n-heptane (C7H16) were used as surrogates for diesel. Furthermore for WCO, surrogate mixtures of methyl decanoate, methyl-9-decenoate and n-heptane were used. Thermochemical and reaction kinetic data (115 species and 460 reactions) were implemented in the CFD code to simulate the spray and combustion processes of the two fuels. Validation of the spray liquid length, ignition delay, flame lift-off length and soot formation data were performed against previous published experimental results. The modeled data agreed with the trends obtained in the experimental data at all injection pressures. Further investigations, which were not achieved in previous experiments, showed that prior to main ignition, a first stage ignition (cool flame) characterized by the formation formaldehyde (CH2O) species at low temperature heat release occurred. The main ignition process occurred at high temperature with the formation of OH radicals. Furthermore, it was observed that the cool flame played a greater role in stabilizing the downstream lifted flame of both fuels. Increase in injection pressure led to the cool flame location to be pushed further downstream. This led to flame stabilization further away from the injector nozzle. WCO had shorter lift-off length compared to diesel as a result of its cool flame which being closer to the injector. Soot formation followed similar trends obtained in the experiments.Citation
Kuti, O. A., Sarathy, S. M., & Nishida, K. (2020). Spray combustion simulation study of waste cooking oil biodiesel and diesel under direct injection diesel engine conditions. Fuel, 267, 117240. doi:10.1016/j.fuel.2020.117240Sponsors
The authors will like to thank the KAUST high performance computing (HPC) laboratory for their assistance in using many computer CPUs for the simulation activities.Publisher
Elsevier BVJournal
FuelAdditional Links
https://linkinghub.elsevier.com/retrieve/pii/S0016236120302350ae974a485f413a2113503eed53cd6c53
10.1016/j.fuel.2020.117240