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Knock is one of the main factors limiting the efficiency of spark-ignition engines. The introduction of alternative fuels with elevated knock resistance could help to mitigate knock concerns. Alcohols are prime candidate fuels and a model that can accurately predict their autoignition behavior under varying engine operating conditions would be of great value to engine designers. The current work aims to develop such a model for neat methanol. First, an autoignition delay time correlation is developed based on chemical kinetics calculations. Subsequently, this correlation is used in a knock integral model that is implemented in a two-zone engine code. The predictive performance of the resulting model is validated through comparison against experimental measurements on a CFR engine for a range of compression ratios, loads, ignition timings and equivalence ratios.

Using liquid alcohols, such as methanol and ethanol, in spark-ignition engines is a promising approach to decarbonize transport and secure domestic energy supply. Methanol and ethanol are compatible with the existing fuelling and distribution infrastructure and are easily stored in a vehicle. They can be used in internal combustion engines with only minor adjustments and have the potential to increase the efficiency and decrease noxious emissions compared to gasoline engines. In addition, methanol can be synthesized from a wide variety of sources, including renewably produced hydrogen in combination with atmospheric CO₂. Presently, during the production of ethanol or methanol a dehydration step is always applied. This step accounts for a significant part of the entire production process' energy consumption and thus, from an economical point of view, methanol and ethanol could become more interesting alternative fuels if the costs related with dehydration could be reduced.

The use of methanol as spark-ignition engine fuel can help to increase energy security and offers the prospect of carbon neutral transport. Methanol's properties enable considerable improvements in engine performance, efficiency and CO2 emissions compared to gasoline operation. SAE paper 2012-01-1283 showed that both flex-fuel and dedicated methanol engines can benefit from an operating strategy employing exhaust gas recirculation (EGR) to control the load while leaving the throttle wide open (WOT). Compared to throttled stoichiometric operation, this reduces pumping work, cooling losses, dissociation and engine-out NOx. The current paper presents follow-up work to determine to what extent these advantages still stand over an entire drive cycle. The average vehicle efficiency, overall CO2 and NOx emissions from a flexible fuel vehicle completing a drive cycle on gasoline and methanol were evaluated.

Models for the convective heat transfer from the combustion gases to the walls inside a spark ignition engine are an important keystone in the simulation tools which are being developed to aid engine optimization. The existing models have, however, been cited to be inaccurate for hydrogen, one of the alternative fuels currently investigated. One possible explanation for this inaccuracy is that the models do not adequately capture the effect of the gas properties. These have never been varied in a wide range because air and ‘classical’ fossil fuels have similar values, but they are significantly different in the case of hydrogen. As a first step towards a fuel independent heat transfer model, we have investigated the effect of the gas properties on the heat flux in a spark ignition engine.

The internal combustion engine with compression ignition is still the most important power plant for heavy duty transport, railway transport, marine applications and generator sets. Fuel cost and emission regulations drive manufacturers to switch to alternative fuels. The understanding and prediction of these fuels in the spray and combustion process will be very important for these issues. In the past, lot of research was done for conventional diesel fuel by optically analyzing both spray and combustion. However comparison between different groups is difficult since qualitative results and accuracies are depending in the used definitions and methods. The goal of present research is to verify the behavior pure oils compared to more standard fuels while paying lot of attention to the interpretation of the measurement results.

The use of light alcohols as SI engine fuels can help to increase energy security and offer the prospect of carbon neutral transport. These fuels enable improvements in engine performance and efficiency as several investigations have demonstrated. Further improvements in efficiency can be expected when switching from throttled stoichiometric operation to strategies using mixture richness or exhaust gas recirculation (EGR) to control load while maintaining wide open throttle (WOT). In this work the viability of throttleless load control using EGR (WOT EGR) or mixture richness (WOT lean burn) as operating strategies for methanol engines was experimentally verified. Experiments performed on a single-cylinder engine confirmed that the EGR dilution and lean burn limit of methanol are significantly higher than for gasoline. On methanol, both alternative load control strategies enable relative indicated efficiency improvements of about 5% compared to throttled stoichiometric operation.