Third Party Funds Group - Overall project
Acronym: AlcoFuels
Start date : 01.07.2025
End date : 30.06.2027
The project aims to evaluate the injection of alcohol-based fuels, such as methanol (particularly cavitation and spray formation), when blended with (salt)water, oil, gasoline, diesel, and additives, as well as the resulting effects on erosion. Using a combined experimental/numerical approach, the injection behavior and characteristic features of alcohols for use in marine engines are being investigated.
FAU Erlangen-Nürnberg is conducting optical measurements of spray/jet formation for simulation validation and as a basis for mixture field modeling. Microscopic images provide insight into the initial jet breakup. These findings are supported by X-ray measurements from Argonne National Laboratory (ANL).
Ruhr University Bochum (RUB) conducts simulations regarding internal nozzle flow, near-nozzle spray, and erosion zones. Based on measurement data from Sandia National Laboratories (SNL) on transparent nozzles, a cavitation model is developed and validated.
The Technical University of Darmstadt (TUD) simulates spray/jet formation based on data from RUB and validates these results against data from FAU. Temperature distributions are extracted to draw conclusions about the influence of high heat of vaporization on ignition characteristics under engine operating conditions.
The shipbuilding and maritime equipment industry is facing incisive changes as the IMO GHG Strategy includes an enhanced common ambition to reach net-zero GHG emissions from international shipping by or around 2050 (including indicative check-points for 2030 and 2040), and a commitment to ensure an uptake of alternative zero and near-zero GHG fuels by 2030. Sustainable solutions for marine engines are urgently needed, both ecologically and economically. On the economic side, many companies that are dependent on regional maritime markets or even individual maritime customers are small and medium-sized enterprises, which consequently have a great interest in and a high demand for sustainable ship propulsion systems.
Renewable methanol is one of the most promising fuels for CO2-neutral applications, especially in the marine sector for large engines. The fuel properties as a neat substance or in the mixture with ethanol, petrol, and water have a significant influence on the fuel spray resulting from injection and thus the mixture formation and emission generation, as well as on the cavitation and erosion behaviour in the nozzle. A basic understanding of cavitation, spray and mixture formation processes with methanol and its blends has to be created to face the resulting development challenges.
The project goal is to investigate the injection process, especially cavitation and spray formation, of methanol in neat form and in mixtures with (salt) water, engine oil, petrol, Diesel, and additives, as well as the impact on erosion. A combined experimental/numerical approach is suggested. Investigations are carried out with an industrial injector as well as the ECN Spray D model injector.
FAU Erlangen-Nürnberg conducts injection rate and optical measurements of spray and jet formation that act as validation data set for simulation and basis for modelling of the mixture field. Microscopic imaging with Laser-induced Fluorescence (LIF) gives detailed insight into primary break-up in the first few millimetres after nozzle exit.
Sandia National Laboratories (SNL) carry out optical measurements of spray and jet formation for reconciliation with FAU ensuring transferability of results from different sites. Experiments with transparent nozzles give insight into the in-nozzle flow and cavitation.
Argonne National Laboratory (ANL) together with FAU and SNL performs X-ray measurement techniques at ANL’s synchrotron particle accelerator. Those measurements deliver data regarding in-nozzle flow via in-situ X-ray imaging of actual metal injector nozzles as well as the nozzle near-field with exceptionally high resolution. These very complex measurements underpin the laboratory measurements of FAU and SNL and significantly increase the validity of their data sets.
Ruhr-Universität Bochum (RUB) conducts simulations of the in-nozzle flow and establishes a post-processing tool chain in terms of in-nozzle flow, nozzle-near spray, and erosion sensitive wall zones. A mass-transfer cavitation model is developed and validated using measurements with a sonotrode and data from SNL. The nozzle-near spray field is validated based on measurements from FAU. Suggestions for a more erosion resistant design and operation of injectors are given.
TU Darmstadt (TUD) simulates spray and jet formation building up on the data of RUB, which is integrated in the simulation workflow. The numerical investigations are validated with experimental data. Methanol with an enthalpy of evaporation of hvap = 1.1 MJ/kg and a lower heating value of hcomb = 20 MJ/kg has a more than nine times higher ratio of hvap to hcomb than standard Diesel fuel. The comparatively high injected mass of methanol in combination with the high latent heat of evaporation influences mixture formation, ignition and combustion. To gain insight into this matter, temperature distributions are extracted.
A novel seamless and validated description of the whole process chain of maritime methanol injection from in-nozzle flow to mixture formation is generated by the integration and combination of advanced optical and numerical methods. The use of an industrial and an academic injector ensures maximum dissemination and relevance to the scientific community as well as industry.