Steen Sjolander, BEng/72, MEng/75, seeks to improve the aerodynamics of gas turbine engines. His work with Pratt & Whitney Canada has helped make very light jets a reality.
The VLJ, a business jet weighing less than 4.5 metric tons (or 10,000 pounds), is a small twin-engine plane designed for short-haul flights of about 1,000 to 2,000 kilometres (or 600 to 1,200 miles). This smaller, lighter and less expensive jet could open the door for on-demand jet service — taxis of the sky, operating out of small airports.
VLJs are being developed by competing manufacturers, including Eclipse Aviation, Cessna Aircraft and Embraer. But they all depend on engines developed at the Canadian division of Pratt & Whitney in collaboration with Carleton University.
“I’ve been working with Pratt & Whitney Canada for 20 years on the aerodynamics of engines. Even a one percent improvement makes a difference in this industry,” says Steen Sjolander, BEng/72, MEng/75.
The Pratt & Whitney Canada Research Fellow and chancellor’s professor in the Department of Mechanical and Aerospace Engineering simulates conditions in the engine in the Pratt & Whitney Canada High Speed Laboratory — Carleton’s supersonic wind tunnel.
“Gas turbine engines are a mature and sophisticated technology, so we won’t see quantum leaps, but we continue to push beyond the current limits in design,” says Sjolander. “To make a low-cost aircraft, a manufacturer needs an engine with lighter components, fewer parts and reduced maintenance needs.”
To achieve that, Pratt & Whitney comes to the university in order to push the envelope, test aggressive design and incorporate new understandings, says Sjolander. Once a clever idea has been proposed and preliminary work on it looks promising, Carleton gets involved to determine whether it works, why it works and how it can work better.
For instance, Sjolander, working with a research engineer and four graduate students, is attempting to reduce the number of blades on a turbine while still achieving the same power and safety. Such a reduction would further reduce both the cost and weight of the turbine.
“Students working on these projects realize that their work is of tremendous interest to the frontline designers,” says Sjolander. “Their concepts and results have an industrial impact.”
That impact, often years down the line in terms of technological readiness since risky technology is never put into flight, can be seen in the Pratt & Whitney small engines that make the VLJ feasible. But while the airline industry and passengers wait for this new generation of aircraft, Sjolander and his team are already working on the generation to follow.
