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Brunel Reveals Major Breakthrough in Cost Effective New Air Hybrid Engine

Brunel University's School of Engineering and Design today announced groundbreaking results from simulations which suggest a normal combustion engine can be adapted into a new air hybrid engine at very low cost. The resulting new air hybrid engine would be considerably cheaper to run and deliver significantly less carbon emissions.

The idea is that using the engine's compression to brake the vehicle, not only could slow the vehicle down, but also the pistons could compress air and drive it into a compressed air tank. It could then be used later to briefly power the piston and to provide compressed air for turbo charging during a period of turbo lag (normally at low revolutions).

Hybrid vehicles use energy management to save fuel. This includes switching off the engine when not in use, restarting the engine when needed and recovering the braking energy for other use. The means for achieving this type of energy management could be electric (e.g. Toyota Prius) but it is equally feasible to use mechanical means such as pneumatic, an air hybrid in which the regenerative energy is stored pneumatically and thermally.

Transforming an existing combustion engine into an electric hybrid is very expensive. It requires a complete redesign of the transmission system; it's heavier because it uses extra batteries; more space is required to house these batteries and they have a limited lifecycle which means recycling is an issue.

For the last ten years, engineers have been attempting to transform an existing combustion engine into an air (pneumatic) hybrid. It was based on the theory of using electro-magnetic or electro-hydraulic valves to open and close the intake in the exhaust valve which is proving costly.

Brunel University has run simulations which require only small alterations to adapt a normal combustion engine into an air hybrid engine using production technologies. The simple and very cost effective solution needs no transmission alteration or engine redesign.

The simulations were successful and now Brunel is looking for OEM's of bus and light utility vehicles to test the new engine.

Prof. Hua Zhao, Director for Advanced Powertrain and Fuels Research at Brunel, said: “Significantly reducing the cost of driving through reducing fuel consumption and lowering carbon emissions for commercial vehicles is an ongoing battle. Our simulations prove that we have achieved a major breakthrough. Now, we need to test it with vehicle manufacturers.“

Contact details
For more information about Brunel's results, please contact Ben Philipson, Katy Askew or Dominique Nunes at the Racepoint Group on 020 8752 3200 or