biofuel bubbles

Researchers at the University of Gothenburg are studying how bubbles form in a drop of biodiesel in a bid tohelp future engines get the most energy out of the fuel.

In an internal combustion engine, the fuel is distributed in small droplets in injection valves to maximise combustion. In the engine, the fuel droplets are pressurised to turn into gas and burn. When gas is formed, bubbles form inside the droplets and it is these that the researchers at the University have studied using femtosecond lasers.

“The bubbles have a significant impact on the atomisation of biodiesel in engines. Therefore, our research is very important to address fundamental questions about the efficiency of the biodiesel engine,” said Dr Yogeshwar Nath Mishra, who led the study together with Professor Dag Hanstorp.

Researchers are trying to understand how and when the bubbles form in the fuel droplets. In the long term, this knowledge could lead to the development of a more efficient engine that burns more fuel than today, resulting in less environmentally harmful emissions.

“Research on biodiesel is crucial in our transition from fossil fuels to combat climate change. In engines, bubbling affects fuel combustion and contributes to the formation of larger droplets that do not evaporate and burn completely, leading to increased emissions,” said Dr Yogeshwar Nath Mishra.

Studying bubble formation in engine injection valves is difficult because of their structure, with narrow channels in metal bodies. But with the latest technology, physicists can set up an experiment in the lab that allows them to study the process in a millimetre-sized drop of biodiesel.

The results, published in Nature Scientific Reports, have provided significant insights into the phenomenon of bubble formation but Professor Hanstorp said there is still a lot of development to be done before they can be used.