Made at UCL


Water doping for diesel engines

How a UCL student and his thesis supervisor researched an open-source approach to reducing air pollution from diesel engines following concerns raised by a London resident.

Water doping for diesel engines

Air pollution is a serious and growing problem in London. Pollutants that can be very harmful for human lungs are emitted by diesel-powered engines. One way to reduce the exhaust emissions is to modify the combustion process in diesel engines so that fuel burns more cleanly and efficiently, reducing the production of these pollutants.

Adding water to engine intake air can reduce combustion temperatures and the formation of nitrogen oxides and particulates. There is now a variety of ‘water doping’ technologies for diesel engines using water, mist and/or steam. While some of these technologies are available commercially, their cost could prevent them from becoming a widespread solution to diesel engine pollutants in the UK.

Alan Cooper, a citizen concerned about the impact of airborne nanoparticles on his family and neighbourhood, approached the Engineering Exchange (EngEx) at UCL for support in developing an open-source design for a water-doping technology that could reduce emissions of particulates and nitrogen oxides when fixed to diesel engines. 

To facilitate this, Dr Paul Hellier (UCL Mechanical Engineering), a specialist in sustainable energy concepts for internal combustion engines, supervised Seifeldin Mohamed Said Mattar, a student who chose to undertake the research for his MSc thesis.

Seifeldin’s project comprised the first stage in a larger project looking at temperature, water flow rate and electrostatic charge conditions and how these might affect the composition of the engine intake gas. With input from London’s concerned citizens, support from the EngEx, and hard work from our talented staff and students, UCL will continue to undertake research to improve air quality in London.



  • Credit: Ben Kerckx, Source: Pixabay