Blended airfoil technology

Citation

(2003), "Blended airfoil technology", Aircraft Engineering and Aerospace Technology, Vol. 75 No. 3. https://doi.org/10.1108/aeat.2003.12775caf.008

"Blended airfoil technology"

Hartzell Propeller has announced the introduction of advanced new design capabilities. Hartzell believes that incorporation of the new technology will allow its aerodynamicists the ability to more readily maximise various elements of propeller performance in specific applications. New propeller designs based on this philosophy are already being made available on many popular general aviation aircraft. Examples include original equipment propellers for the Cirrus SR20 and SR22, the Lancair Legacy and the SOCATA TB20 and TB21. Recent STC'd installations include the Beechcraft Bonanza, Cessna 340 and 414, Piper Dakota and many others. Application of this technology is continuing on new applications, where appropriate (Plate 3).

The "blended" propeller designs is said to allow for the incorporation of different airfoils along progressive sections of a blade. Thus, the design of the blade mid-section may be maximised for developing low-speed thrust while the tip sections may be optimised to reduce noise levels. In the past, most propeller designs for aircraft equipped with piston engines made use of one basic airfoil series across the entire length of the blade which can compromise aircraft performance or produce high noise levels.

Plate 3

In addition, the blended airfoil design process was implemented in conjunction with new propeller planform designs, such as Hartzell's swept-tip scimitar props. When properly engineered, the use of tip sweep minimises the strength of the sonic shock wave at the propeller blade tips and in combination with the blended airfoil designs can, it is believed, provide significant reductions in noise and increased performance. The new technology was developed by Hartzell through its involvement in various specialised applications for NASA, as well as for record breaking propellers designed for Bruce Bohannon's Flying' Tiger and for record setting Lancairs racing at Reno. At the same time Hartzell has recently developed advanced next generation manufacturing capabilities for propeller blades. The goals of all these efforts are to produce mission optimised propellers able to incorporate absolute maximum flight performance, reduced noise profiles and greater blade-to-blade accuracy.

Details available from: Hartzell Propeller Inc. Tel: +1 937 778 4200; Fax: +1 937 7784321.