Posted on: 01 November 2011 by Mark Howells
Bombardier Aerospace reports that the final results of a three-phase windtunnel test programme have provided further validation of the CSeries aircraft’s aerodynamic design and also support design predictions that the CSeries family will deliver a step-change in fuel efficiency.
The manufacturer says that the tests also contributed to the achievement of optimal integration of Pratt & Whitney’s PurePower PW1500G engine.
Validation of the CSeries aircraft’s aerodynamic design included extensive use of computational fluid dynamics (CFD), made possible through the use of contemporary supercomputers that are significantly more capable – and 100,000 times faster – than computers available when the aircraft currently serving the 100- to 149-seat market were designed. These tools permitted the minimisation of interference drag and also facilitated the design of the engine nacelle and thrust reverser.
To simulate actual flying conditions, the windtunnel tests were conducted with over 20 sophisticated scale models over more than 4,500 testing hours at facilities in Canada, France, Germany, the Netherlands, the United Kingdom and the United States.
"Simulated conditions during the windtunnel tests closely correlate to real world flying conditions and the resulting data were used to improve and validate final CSeries aircraft design and systems," explained David Tidd, vice-president, CSeries integrated product development, Bombardier Commercial Aircraft. "This latest achievement for the CSeries represents the most extensive and complex windtunnel testing that Bombardier has ever conducted; it marks another key advance in the development."
The scale models of the CSeries aircraft used in the testing were equipped with precise instrumentation to measure air flow, including as many as 700 pressure-sensitive ports over the wings, fuselage and tail. The models included moving parts, such as wing flaps and leading edge slats, which could be repositioned to reflect actual flying events. Some models were equipped with miniature air-driven turbine engines to gauge the air flow interference with the aircraft wings. The largest of the models, at 13.7% scale, had a wingspan of approximately 4.5 metres (15 feet).
Using the scale models and the environmental conditions possible in the windtunnels, Bombardier engineers simulated the aerodynamics of the CSeries in various flight scenarios such as landing, takeoff and cruising at high altitudes.
The CSeries family is being designed to offer: a 15% cash operating cost advantage and a 20% fuel burn advantage; greatly reduced noise and emissions; superior operational flexibility, exceptional airfield performance; and a range of 2,950 nm (5,463 km). It will also provide passengers with widebody-style seating in a single-aisle aircraft.
Bombardier has 133 firm orders for CSeries aircraft – 61 CS100s and 72 CS300s. The programme has also booked options and purchase rights for an additional 129 aircraft.