Laser ignition to help cut emissions

Replacing the conventional spark ignition with laser ignition enables much greater control over the combustion of the air/fuel mixture. Dr Tom Shenton, a senior lecturer at the University of Liverpool is the principal investigator on the project. He said: "The key to reducing emissions in the spark ignition engine is improved control. For the last 100 years the primary means of ignition control has been the spark plug. But, with laser ignition we have an exciting alternative which will give much greater scope for engine controller optimisation and the implementation of new engine designs." Unlike the sparkplug ignition system, which fires just one, or at best two, sparks right next to the combustion chamber roof, it is possible to 'aim' a laser ignition system to ignite the fuel anywhere in the combustion chamber, therefore focusing the beam where the fuel is most concentrated. By using ultrafast computing to direct the laser, the engine can be run on a much more efficient or 'leaner' air/fuel mixture, which would directly cut a car's carbon emissions. This heightened control also helps overcome the poor cold start performance of engines running high blends of biofuels. The laser beam can be delivered to the combustion chamber through a thin fibre optic cable, taking up less space than the spark plug, making room for larger diameter valves, enabling better combustion through more efficient gas flow through the engine. The University of Liverpool has received a £198,910 grant from the Carbon Trust to develop the technology. Mark Williamson, director of innovations at the Carbon Trust, said: "Laser ignition is a really exciting technology because it improves the efficiency of petrol cars and could, in the future, speed the uptake of cars run on biofuels derived from sustainable organic materials such as algae."