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Methanol has recently emerged as a promising fuel for internal combustion engines due to its multiple carbon-neutral production routes and advantageous properties when combusting. Methanol is intrinsically more suitable for spark-ignition (SI) operation thanks to its high octane number, but its potential in heavy-duty applications also encourages engine manufacturers in this field to retrofit their existing compression-ignition products into methanol/diesel dual-fuel (DF) operation. For both SI operation and DF operation, injecting methanol into the engine’s intake path at low pressure is a relatively simple and robust method to introduce methanol into the cylinders. However, the much higher heat of vaporization (HoV) of methanol compared to conventional SI fuels like gasoline can be a double-edged sword.

Methanol is a promising fuel for future spark-ignition engines. Its properties enable increased engine efficiency. Moreover, the ease with which methanol can be reformed, using waste exhaust heat, potentially offers a pathway to even higher efficiencies. The primary objective of this study was to build and validate a model for a methanol fueled direct-injection spark-ignition engine with on-board fuel reforming for future investigation and optimization. The second objective was to understand the combustion characteristics, energy losses and engine efficiency. The base engine model was developed and calibrated before adding a reformed-exhaust gas recirculation system (R-EGR). A newly developed laminar burning velocity correlation with universal dilution term was implemented into the model to predict the laminar burning velocity with the presence of hydrogen in the reforming products.

Partially premixed combustion (PPC) is one of several advanced combustion concepts for the conventional diesel engine. PPC uses a separation between end of fuel injection and start of combustion, also called ignition dwell, to increase the mixing of fuel and oxidizer. This has been shown to be beneficial for simultaneously reducing harmful emissions and fuel consumption. The ignition dwell can be increased by means of exhaust gas recirculation or lower intake temperature. However, the most effective means is to use a fuel with high research octane number (RON). Methanol has a RON of 109 and a recent study found that methanol can be used effectively in PPC mode, with multiple injections, to yield high brake efficiency. However, the early start of injection (SOI) timings in this study were noted as a potential issue due to increased combustion sensitivity. Therefore, the present study attempts to quantify the changes in engine performance for different injection strategies.

Diesel spray experimentation at controlled high-temperature and high-pressure conditions is intended to provide a more fundamental understanding of diesel combustion than can be achieved in engine experiments. This level of understanding is needed to develop the high-fidelity multi-scale CFD models that will be used to optimize future engine designs. Several spray chamber facilities capable of high-temperature, high-pressure conditions typical of engine combustion have been developed, but because of the uniqueness of each facility, there are uncertainties about their operation. The Engine Combustion Network (ECN) is a worldwide group of institutions using combustion vessels, whose aim is to advance the state of spray and combustion knowledge at engine-relevant conditions. A key activity is the use of spray chamber facilities operated at specific target conditions in order to leverage research capabilities and advanced diagnostics of all ECN participants.

Hydrogen-fueled internal combustion engines (H₂ICEs) are an affordable, practical and efficient technology to introduce the use of hydrogen as an energy carrier. They are practical as they offer fuel flexibility, furthermore the specific properties of hydrogen (wide flammability limits, high flame speeds) enable a dedicated H₂ICE to reach high efficiencies, bettering hydrocarbon-fueled ICEs and approaching fuel cell efficiencies. The easiest way to introduce H₂ICE vehicles is through converting engines to bi-fuel operation by mounting a port fuel injection (PFI) system for hydrogen. However, for naturally aspirated engines this implies a large power penalty due to loss in volumetric efficiency and occurrence of abnormal combustion. The present paper reports measurements on a single-cylinder hydrogen PFI engine equipped with an exhaust gas recirculation (EGR) system and a supercharging set-up.

In 2004 the European Parliament ratified the Euro III and IV standards limiting the pollutant emission of, among others, rail and marine diesel engines. In these sectors, it is particularly important to keep any fuel consumption penalty, when reducing emissions, to a strict minimum. Furthermore, exhaust gas after treatment is mostly avoided for cost reasons. Thus, manufacturers are looking to pretreatment of fuels, alternative fuels, and limiting engine-out emissions as ways to attain the required emission levels. This paper discusses the experimental work done on a 1324 kW, 1000 rpm six cylinder marine diesel engine equipped with mechanical unit injectors. The aim was to determine the influence of compression ratio and fuel injection parameters on engine-out emissions, with emphasis on NOx emissions. A range of fuel injection parameters were examined, varying the start of injection, pump plunger diameter, injection pressure, and injector nozzle geometry.