Numerical Investigation of the Impact of Fuel Flow Rate on Combustion in a Heavy Duty Diesel Engine
2022-01-0481
03/29/2022
- Content
- Diesel engines are one of the most popular combustion systems used in different types of heavy-duty applications because of higher efficiencies compared to the spark ignition engines. Combustion phasing and the rate of heat release in diesel engines are controlled by the rate at which the fuel is directly injected near top dead center which participates in a predominantly mixing controlled combustion. In the present work, computational fluid dynamics (CFD) simulations were carried out on a heavy-duty diesel engine in order to understand the effect of injection timing and the nozzle flow rate on its combustion and emission characteristics. The engine operates at a speed of 1500 rev/min., and a compression ratio of 20.5. It is equipped with a 16-hole injector, which injects fuel into the engine cylinder in a single injection pulse. The injector nozzles are arranged in two rows containing 8 nozzles in each row. KH-RT model was used to model the spray break up while the finite rate chemistry was used to model combustion. The rate of injection of fuel from the two nozzle rows was obtained from the in-nozzle flow simulations. The simulation results showed that it is important to consider the difference in fuel flow rates ensuing from the two nozzle rows in order to simulate the combustion characteristics of the engine. The simulation results were compared with experimental results over a range on injection timings. It was found that the CFD model predicted the combustion behavior of the engine reasonably well over the entire range of operating conditions.
- Citation
- Addepalli, S., Scarcelli, R., Wang, Y., Vojtech, R. et al., "Numerical Investigation of the Impact of Fuel Flow Rate on Combustion in a Heavy Duty Diesel Engine," SAE Technical Paper 2022-01-0481, 2022, .