Circulation Control and Its Application to Extreme Short Take-Off and Landing Vehicles

Abstract

Circulation Control is a high-lift method discovered in 1935 when Henry Coanda accidentally stumbled upon the technology. Research was conducted in the 1970's and 1980's to develop this technique, but the idea fell out of vogue until recently. Energy is introduced into the flow field by means of a jet ejected tangentially from a slot located near the trailing edge of the airfoil; thus changing the effective chamber of the airfoil and increasing lift. Extreme Short Take-Off and Landing (ESTOL) vehicles can use this technology to alleviate today's congested airports by reutilizing the small runways that are currently unexploited due to the recent trend of bigger aircraft. By examining the angle-of-attack, flap deflection angle, and jet blowing coefficient, a design space was analyzed for lift and drag revealing three-dimensional lift coefficients up to 3.5. After collecting the data, balanced field length and landing distances were calculated. These results revealed that the shortest balanced field length of 2,400 feet would be for a flap deflection angle of thirty degrees and a blowing coefficient equal to 0.35. Similarly, the shortest landing distance was calculated to be 2,000 feet for a flap deflection angle of ninety degrees and a blowing coefficient of 0.34. Both of these values fall within the NASA defined mission requirements 46 for an ESTOL aircraft to have a balanced field length and landing distance between 2,000 to 3,000 feet, proving Circulation Control to be an extremely viable resource for ESTOL technology.

Sensitivity Analysis and Technology Evaluation for a Roadable Personal Air Vehicle at the Conceptual Design Stage

“…This results in an increase in the lift force due to the generation of the downwash effect. According to a computational experiment by Montanya and Marshall [24], the lift coefficient of a NASA SC (2)-0414 airfoil with a 30 degree flap angle is increased by 30% compared to the zero flap angle case; the lift coefficient is estimated to be 3.3. The k factor for the lift coefficient in this study was defined with values of 0.1 and −0.15 for the friction drag and 0.01 and 0.05 for the aero structure weight factor and electronics weight factor, respectively.…”

Overview of Recent Circulation Control Modeling Activities at Cal Poly

“…The Circulation Control, CC, work at Cal Poly started as an applied aerodynamics and aircraft design project by de la Montanya and Marshall. 35,36 The task was to investigate the integration of CC technologies into an aircraft design. This preliminary work studied how to model the dual radius flap design and integrate the results into an aircraft design.…”

Adaptive Control for ESTOL Design Abstractions-Performance Analysis

“…The design abstractions represent ESTOL or STOL technology found in literature. 3,[10][11][12][13][14][15][16][17][18] Presently, there are five different ESTOL technologies modeled in the Research Aircraft Simulation Modeling Tool. The modeling tool provides the capability to employ each ESTOL technology individually, or simultaneously with other ESTOL technologies.…”