Diesel combustion

Diesel combustion

Combustion and Exhaust Emission Characteristics of Diesel Micro-Pilot Ignited Dual-Fuel Engine

In a diesel engine, fuel is introduced as the piston approaches the top dead centre of its stroke. The fuel is introduced under high pressure either into a precombustion chamber or directly into the piston-cylinder combustion chamber. With the exception of small, high-speed systems, diesel engines use direct injection.

Study on Premixed Combustion in a Diesel Engine with Ultra-multihole Nozzle

Study on Premixed Combustion in a Diesel Engine with Ultra-multihole Nozzle

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Modeling and Simulation of Compression Ignition Engines

Modeling and Simulation of Compression Ignition Engines

Compression ignition engine combustion involves a wide range of time and length scales that cannot be fully resolved in a single simulation even on current supercomputers. Hence, a three step simulation approach has been developed at the ITV, which decomposes the physical process into three one-way coupled simulations. This simulation framework consists of high-fidelity simulations of the nozzle internal flow, the primary breakup in the vicinity of the nozzle orifice, and reactive spray simulations further downstream.

1.4. Comparison of emissions from different engines

1.4. Comparison of emissions from different engines

The mining industry is energy intensive. By co-combusting hydrogen in a conventional miner truck engine, the solution aims to reduce the CO₂ footprint of mining products and the dependence of the mining industry on fossil fuels. The suggested approach is to use a modified conventional diesel engine and substitute most of the diesel fuel with hydrogen. The solution focuses on the development of a mining truck prototype powered by a dual-fuel hydrogen/diesel engine, which includes an onboard hydrogen storage system to test the powertrain on a truck in a mine.

Running more detailed chemistry models on GPUs, researchers improve predictions for nitrogen oxides

Running more detailed chemistry models on GPUs, researchers improve predictions for nitrogen oxides

With the LTC process, the engine compresses a dilute fuel-air mixture, raising its density and temperature. This process, known as compression ignition, causes the fuel-air mixture to autoignite. To dilute the fuel-air mixture so that it has a lower proportion of fuel in it than conventional combustion would, the engine uses either excess intake air or recirculated exhaust gas.

Engine system for modeling and validation

Engine system for modeling and validation

This study proposes a simple combustion model of a diesel engine for control of MFI (comprising double-pilot fuel injections and a main injection). The model is based on our previous SFI model but adds several representative points for the pilot fuel injections. The model accuracy was evaluated in comparisons with engine experiments.

Effects of combustion chamber geometry on diesel combustion

Effects of combustion chamber geometry on diesel combustion

The Centre supported both experimental and numerical research with a strong focus on enabling improvements in efficiency and emissions on next generation engines by extending the scientific knowledge. Our state-of-the-art engine test facility, developed in partnership with Jaguar Land Rover, for six years supported JLR diesel research. 

The German automotive industry is the leader in diesel

The calorific value of diesel fuel is roughly 45.5 MJ/kg (megajoules per kilogram), slightly lower than petrol which is 45.8 MJ/kg. However, diesel fuel is denser than petrol and contains about 15% more energy by volume (roughly 36.9 MJ/litre compared to 33.7 MJ/litre). Accounting for the difference in energy density, the overall efficiency of the diesel engine is still some 20% greater than the petrol engine, despite the diesel engine also being heavier.

Low temperature combustion could drive efficient, clean diesel engines back into the limelight

Two of the main pollutants in diesel exhaust are both the results of heat. One, nitrogen oxides (NOx molecules) are formed primarily at the highest-temperature point in the engine, the flame itself. When released into the air, these compounds act as inveterate pollutants but also react with sunlight and other particles in the air to form smog. Particulate matter (PM), on the other hand, results from the roiling cauldron of the combustion chamber, and the small pockets of too-high fuel concentration that arise during the combustion process.