The use of supercharging to compensate for the reduction of low-end torque and general driveability from downsized gasoline engines is gaining significance. Increasing numbers of OEMs, suppliers, and engineering consultancies have R&D programs in place.
In the U.K., Ford, Ricardo, and Lontra have been awarded funding from the government's Technology Strategy Board to jointly demonstrate Lontra’s Blade Supercharger. Described by the company as a variable-flow system, it has been designed to meet the boosting needs of heavily downsized gasoline and diesel power units.
Simon Hombersley, Lontra's Business Development Director, described the Blade supercharger as "a small, rotary double-acting positive displacement compressor." He said the design features a variable-flow mechanism "to enable precise matching of demand for the engine.”
He explained that the design reduces leakage and improves airflow, adding that its key benefit for downsized engines is the ability to vary flow in real time to match demand.
"Simple control strategies allow the device to deliver the torque curve required by OEMs,” Hombersley noted.
Lontra's new supercharger is claimed to address the driveability problems that are a challenge for other boosting solutions such as twin turbochargers.
A demonstration vehicle is scheduled for next year and the company, which develops clean technology solutions based around its compressor design. It has other development projects with major auto companies and is in discussion with potential manufacturing partners, added Hombersley.
The supercharger for demonstration will be fitted to a Ford engine.
According to Jason King, Ricardo’s Chief Engineer, Gasoline Engines Product Group, the Blade Supercharger "shows significant potential in delivering efficiency whilst maintaining driveability."
The TSB’s support is part of its fast-track funding stream, which has a streamlined application for projects of 12 months or less.
It has also emerged that Torotrak is involved with other novel supercharger technology.
At the recent 15th Supercharging Conference in Dresden, Germany, forced induction specialist Rotrak presented a technical paper on a mechanical supercharger system that is said to overcome the problems inherent in conventional supercharger and turbocharger systems. A Rotrex supercharger, developed from racing and high-performance applications, is combined with a Torotrak full-toroidal traction drive.
The Rotrak solution connects the supercharger to the engine via a compact variable drive designed to allow efficient operation across the entire engine speed range.
“A fully integrated centrifugal compressor connected to the engine via a variable drive will achieve a unique combination of low- and high-speed performance with a highly cost-effective system,” explained David Burtt, Torotrak's Engineering Manager.
He stated that independent analysis has estimated that the world market for pressure-charged gasoline engines would grow from the current 2.5 million units to 12 million units by 2016.
Rotrak is a 50-50 joint venture between traction drive specialist Torotrak and Rotrex, a developer of centrifugal compressors.