Shape Change of the Upper Surface of an Airfoil by Macro Fiber Composite Actuators

54th AIAA Aerospace Sciences Meeting

Santer

Papadakis

et al. 2016

prepared to be submitted to the 54th AIAA Aerospace Sciences Meeting, 4-8 January 2016This paper investigates the application of a periodically deforming airfoil surface for the purpose of flow control at low Reynolds numbers. A physical model has been fabricated by bonding Macro Fiber Composite (MFC) actuators to the underside of a NACA 4415's suction surface. The results presented build on work by Jones et al.1 First, the behavior of the surface when actuated at a range frequencies is investigated through a combination of photogrammetric and laser sensor measurements. Second, the aerodynamic performance of this novel flow control technique is presented. It is shown that when the actuation frequency 'locks-in' to the surface motion significant improvements in performance are observed in a flight regime notorious for poor airfoil behavior.

Section: Iiia2 Dynamic Deformationsupporting

confidence: 61%

“…It consists of rectangular piezoceramic rods sandwiched between layers of adhesive and electrode polyimide film which contains interdigitated electrodes that transfer the applied voltage directly to the rods. 7 The MFCs can provide distributed dynamic deflection at high frequencies for very little power consumption.…”

mentioning

confidence: 99%

Active Flow Control at Low Reynolds Numbers by Periodic Airfoil Morphing

54th AIAA Aerospace Sciences Meeting

Santer

Papadakis

et al. 2016

“…This was expected and had been observed in previous models. 13 However, the amplitude begins increasing again at around 90 Hz. From figure 7 this can be attributed to a change in the nature of the skins motion at the highest frequencies, possibly due to a different vibration mode.…”

Section: Iiia Surface Measurementsmentioning

confidence: 99%

Open-Loop Flow Control At Low Reynolds Numbers Using Periodic Airfoil Morphing

53rd AIAA Aerospace Sciences Meeting

Debiasi

Bouremel

et al. 2015

Self Cite

This paper investigates the application of a periodically deforming airfoil surface for the purpose of flow control at low Reynolds numbers. A physical model has been fabricated by bonding Macro Fiber Composite actuators to the underside of an airfoil's suction surface. This model is actuated using a high voltage amplifier and has been tested in a closed-loop wind tunnel at Rec = 5 × 10 4 . It was found that at high enough actuation frequencies such a control technique reduces drag and simultaneously increases lift -thus achieving significant improvements in performance in a flight regime notorious for poor airfoil behavior. Furthermore, by delaying the onset of stall, actuation was able to increase the maximum lift achievable by this airfoil section at Rec = 5 × 10 4 which can of benefit to small aircraft at take-off and landing where high lift coefficients are required.

“…The mechanical design previously presented by Debiasi et al 23,24 is applied in this study to both the upper and the lower surfaces on an airfoil. However some improvements have been made to address the shortcomings and enhance the dynamic response observed in a previous type.…”

Section: Introductionmentioning

confidence: 99%

Measurements of a Symmetric Airfoil Morphed by Macro Fiber Composite Actuators

Bouremel

Chan

32nd AIAA Applied Aerodynamics Conference

et al. 2014

Self Cite

This study presents the geometric and aerodynamic properties of a symmetric airfoil model that uses macro fiber composite actuators to change the shape of its upper and lower surfaces. In the design discussed, these thin and light piezoelectric actuators are bonded to the inside and become an integral part of the skin of the upper and lower surfaces of the airfoil. Still-air and wind-tunnel measurements in different flow regimes are performed to assess the characteristics associated with the changes of the shape of the airfoil. The results obtained will be used to design and fabricate a wing with morphing surfaces for testing in a remote-controlled aircraft. Nomenclaturec = model chord C D = drag coefficient C L = lift coefficient C M = pitching-moment coefficient about c/4 D = drag force L = lift force l = local coordinate tangent to the airfoil surface n = local coordinate normal to the airfoil surface Re c = Reynolds number based on the chord s = model span (from wall to wall of the wind tunnel) U = flow velocity x = streamwise coordinate of the wind tunnel y = spanwise coordinate of the wind tunnel z = vertical coordinate of the wind tunnel Greek letters  = angle of attack of the airfoil  = axial (chordwise) coordinate of the airfoil  = normal coordinate of the airfoil Subscripts