Modelling Ignition Processes of Palm Oil Biodiesel and Diesel Fuels Using a Two Stage Lagrangian Approach

Abstract

The ignition characteristics of palm oil biodiesel and conventional diesel fuels are simulated using the two stage Lagrangian (TSL) 0-D modeling technique. For the diesel fuel surrogate, thermochemical and reaction kinetic data of n-heptane detailed mechanism was utilized. For the palm biodiesel, simulations were done using the reduced mechanisms for the palm oil biodiesel using mixture of methyl decanoate, methyl decenoate and n-heptane as surrogates. Validations of the simulated data were performed against experimental results. The simulation results were able to reproduce the experimental trends in the ignition delay. The chemical kinetic processes responsible for controlling ignition were investigated using the TSL model.

Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

“…Inputs writes both text and binary output files [24]. Details of the formulation and description of TSL can be found in previous works [22][23][24][25][26].…”

“…In engines, ignition delay is the time difference between the start of injection (SOI) to the start of combustion (SOC) [21,22]. The ignition of typical alkane fuels having NTC behavior is governed by three distinct regimes: first-stage ignition, NTC regime and second-stage ignition.…”

“…However, this is achieved at the expense of increasing emissions of unburned hydrocarbons, and decrease in overall engine cycle efficiency [22,50]. Also, it is a common practice in IQT experiments to simulate EGR effect by decreasing charge oxygen concentration [33,34].…”

“…It consists of a physical ignition delay (atomization, vaporization and mixing of fuel and air) and a chemical ignition delay. The chemical ignition delay period of the overall ignition delay occur once the gaseous fuel/air mixture with a suitable temperature and mixture ratio is obtained, such that fast chemical reactions can be initiated [21,22]. The ignition delay in an IQT and a CVCC comprises of both physical and chemical ignition delay periods.…”

“…The two-stage Lagrangian model (TSL) employed in this study describes mixing as a two-stage process that is seen in a frame moving downstream with the normal fluid motion. The model is capable of adopting detailed chemical kinetics while also simulating basic mixing process that are important in turbulent gaseous-jet diffusion flames [18,19,[22][23][24][25][26].…”