scholarly journals Effects of Trailing Edge Deflections Driven by Shape Memory Alloy Actuators on the Transonic Aerodynamic Characteristics of a Super Critical Airfoil

Actuators ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 160
Author(s):  
Binbin Lv ◽  
Yuanjing Wang ◽  
Pengxuan Lei
Keyword(s):  
Mach Number ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Smart Structure ◽  
Trailing Edge ◽  
Edge Based ◽  
Constant Deformation ◽  
Transonic Wind Tunnel

A smart structure to actuate a morphing trailing edge based on the super critical airfoil NASA sc-0714(2) was designed and verified in a transonic wind tunnel. The pressure distribution over the wing was measured to evaluate the structure ability and effects of trailing edge deflections on the aerodynamic characteristics. In the experiment, Mach number was from 0.4 to 0.8, and the angle of attack was from 0° to 6°. The results showed that the smart structure based on shape memory alloy could carry aerodynamic loads under transonic flow and deflect the trailing edge. When the driving force was constant, deformation would be influenced by the Mach number and angle of attack. Increasing the Mach number weakened the actuation capability of the smart structure, which decreased the deflection angle and rate of the trailing edge. The influence of the angle of attack is more complex, and couples with the influence of the Mach number. The higher the Mach number, the stronger the influence of the angles of attack. Additionally, the trailing edge deflection would dramatically change the flow structure over the airfoil, such as the shock wave position and strength. If separation was caused by the trailing edge deflection, the limitation of the smart structure would be further found.

Numerical analysis on shape memory alloy–based adaptive shock control bump

2018 ◽  
Vol 29 (15) ◽  
pp. 3055-3066 ◽  
Author(s):  
Lin Hao ◽  
Jinhao Qiu ◽  
Hongli Ji ◽  
Rui Nie
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Wave Drag ◽  
Initial Shape ◽  
Thermally Activated ◽  
Bump Height ◽  
Shock Control Bump ◽  
Shock Control

A three-dimensional adaptive shock control bump made of shape memory alloy is proposed for transonic wings. The methodology to adaptively change the configuration of the airfoil using the shape memory alloy bump to reduce the shock strength and wave drag is numerically demonstrated using an airfoil RAE2822. The shape memory alloy bump is trained to have a flat initial shape with certain initial strain and can swell up when thermally activated. Boyd–Lagoudas phenomenological model is implemented in finite element method and used to compute the two-dimensional profile and the height of the shape memory alloy bump during thermal activation. The results show that the shape memory alloy bump can generate a considerable deflection due to the reverse phase transformation when thermally activated. The dependence of aerodynamic characteristics of the wing on the height of the shape memory alloy bump and the angle of attack is investigated using computational fluid dynamics method. The results show that there is an optimal bump height for a given angle of attack and the bump with a given height is effective only in certain range of angle of attack. Optimization of bump height and the corresponding driving temperature are carried out under variable angles of attack with the lift-to-drag ratio as the objective function.

Corrugated structures reinforced by shape memory alloy sheets: Analytical modeling and finite element modeling

2018 ◽  
Vol 233 (7) ◽  
pp. 2445-2454 ◽  
Author(s):  
Maryam Koudzari ◽  
Mohammad-Reza Zakerzadeh ◽  
Mostafa Baghani
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Finite Element Modeling ◽  
Shape Memory ◽  
Smart Structure ◽  
Design Parameters ◽  
Asymmetric Mode ◽  
Element Modeling ◽  
Structure Changes

In this study, an analytical solution is presented for a trapezoidal corrugated beam, which is reinforced by shape memory alloy sheets on both sides. Formulas are presented for shape memory alloys in states of compression and tension. According to the modified Brinson model, shape memory alloys have different thermomechanical behavior in compression and tension, and also these alloys would behave differently in different temperatures. The developed formulation is based on Euler–Bernoulli theory. Deflection of the smart structure and the effect of asymmetric response in shape memory alloys are studied. Results found from the semi-analytic modeling are compared to and validated through a finite element modeling, and there is more than [Formula: see text] agreement between two solutions. With regard to the results, the neutral axis of the smart structure changes in each section. The maximum deflection ratio of asymmetric mode to symmetric one mode is 1.7. Additionally, the effect of design parameters on deflection is studied in detail.

Experimental Analysis of Smart Structure with Damping Treatment and SMA

1996 ◽  
Vol 459 ◽  
Author(s):  
Q. Chen ◽  
J. Ma ◽  
C. Levy
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Temperature Effects ◽  
Loss Factor ◽  
Alloy Layer ◽  
Smart Structure ◽  
Viscoelastic Layer ◽  
Heat Cycling ◽  
Damping Materials ◽  
System Frequency

ABSTRACTThe experimental results of a flexible cantilever beam with constrained viscoelastic layer and shape memory alloy layer called smart damping treatment (SDT) are presented. The upper side of the beam is bonded with a viscoelastic layer and then covered with a constraining layer. The lower side is bonded with a shape memory alloy layer, which is used as an actuator. The elastic modulus and loss factor of damping materials are functions of the temperature. The temperature effects on system frequency and loss factor due to heat cycling of SMA layer are evaluated here. It is found that temperature plays an important role on system frequency and loss factor, and thus the temperature effects must be included when discussing such an structure.

scholarly journals Method of approximation of ballistic missile aerodynamic characteristics at the powered flight segment depending on the Mach number and angle of attack

2021 ◽  
pp. 57-63
Author(s):  
P. A. Krasheninnikov
Keyword(s):  
Mach Number ◽  
Drag Coefficient ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Ballistic Missile ◽  
Aerodynamic Coefficients ◽  
Calculation Process ◽  
The Impact

The paper describes the impact of aerodynamic coefficients on the ballistic target (BT) velocity and proposes a method of approximation of the dependence of ballistic target drag coefficient Cxa on the Mach number and angle of attack. The paper proves that the proposed approach allows to substantially reduce errors in drag coefficient simulation, but requires a more complicated calculation process.

Study of Aerodynamic Characteristics of Cylindrical Bodies in a Supersonic Flow

2011 ◽  
Vol 6 (4) ◽  
pp. 16-24
Author(s):  
Vladimir Kornilov ◽  
Vladimir Lysenko
Keyword(s):  
Mach Number ◽  
Aspect Ratio ◽  
Stokes Equations ◽  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Circular Cylinders ◽  
Coordinate Systems ◽  
Flow Parameters ◽  
Cylinder Drag

Analysis of experimental and computational aerodynamic characteristics of smooth flat-face circular cylinders with the aspect ratio of 0,6 to 12,0 is given. Studies have been carried out at Mach number М= 4 for the angle of attack range  = 0900 . Effect of the cylinder aspect ratio and angle of attack on aerodynamic force coefficients in wind axes- and body axes coordinate systems is shown. A number of distinctive peculiarities in the behavior of the cylinder drag coefficient are revealed. The results obtained are presented in a form of a unique generalized dependence. The computation of some flow parameters around a cylinder has been performed within the Navie – Stokes equations, results of which are compared with the flow visualization data

Unsteady aerodynamic characteristics of a morphing wing

2018 ◽  
Vol 91 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Jinwu Xiang ◽  
Kai Liu ◽  
Daochun Li ◽  
Chunxiao Cheng ◽  
Enlai Sha
Keyword(s):  
Lift Coefficient ◽  
Angle Of Attack ◽  
Large Angle ◽  
Unsteady Aerodynamics ◽  
Aerodynamic Characteristics ◽  
Static Case ◽  
Morphing Wing ◽  
Trailing Edge ◽  
Content Type ◽  
Unsteady Aerodynamic

Purpose The purpose of this paper is to investigate the unsteady aerodynamic characteristics in the deflection process of a morphing wing with flexible trailing edge, which is based on time-accurate solutions. The dynamic effect of deflection process on the aerodynamics of morphing wing was studied. Design/methodology/approach The computational fluid dynamic method and dynamic mesh combined with user-defined functions were used to simulate the continuous morphing of the flexible trailing edge. The steady aerodynamic characteristics of the morphing deflection and the conventional deflection were studied first. Then, the unsteady aerodynamic characteristics of the morphing wing were investigated as the trailing edge deflects at different rates. Findings The numerical results show that the transient lift coefficient in the deflection process is higher than that of the static case one in large angle of attack. The larger the deflection frequency is, the higher the transient lift coefficient will become. However, the situations are contrary in a small angle of attack. The periodic morphing of the trailing edge with small amplitude and high frequency can increase the lift coefficient after the stall angle. Practical implications The investigation can afford accurate aerodynamic information for the design of aircraft with the morphing wing technology, which has significant advantages in aerodynamic efficiency and control performance. Originality/value The dynamic effects of the deflection process of the morphing trailing edge on aerodynamics were studied. Furthermore, time-accurate solutions can fully explore the unsteady aerodynamics and pressure distribution of the morphing wing.

Design and Aerodynamic Characteristics Analysis of a Section Morphing Wing Based on Smart Materials

2013 ◽  
Vol 753-755 ◽  
pp. 1764-1767
Author(s):  
Yue Min Yu
Keyword(s):  
Mach Number ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Memory Polymer ◽  
Aerodynamic Characteristics ◽  
Morphing Wing ◽  
Ratio Increase ◽  
Wing Section ◽  
Characteristics Analysis ◽  
Drag Ratio

This paper discusses the design of a section morphing wing that permits a change in the wing section while simultaneously supporting structural wing loads. Section morphing wing allows for two discreet airfoil of the wing. The airfoil 1 is original airfoil maintained by NACA 4412 rib sections. The section morphing wing uses shape memory alloy spring actuator to drive wing section deformation. Skins of the section morphing wing uses shape memory polymer. Computational aerodynamics are used to estimate the performance and dynamic characteristics of each wing section of this section morphing wing as its wing section is changed. Results show that when angle of attach (AOA) is 0 deg, the lift-drag ratio decrease as the airfoil thickness decreases when mach number is less than 0.9 and the lift-drag ratio increase as the airfoil thickness decreases when mach number is greater than 0.9. When AOA is 5deg, the lift-drag ratio increase as the airfoil thickness decreases . The lift-drag ratio decrease as the airfoil thickness decreases when mach number is less than 0.7. When AOA is 10deg, the lift-drag ratio increase as the airfoil thickness decreases when mach number is greater than 0.7. We can chose airfoil 1 or airfoil 2 according to variation flight conditions.

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