Structural Design and Control of a Morphing Winglet to optimize the Aerodynamic Performance of the CRJ-700 Aircraft. Part 2 – Control

In this study, the morphing technology was applied on winglets for the CRJ-700 transport regional aircraft with the aim to improve its aerodynamic performance. The LARCASE Virtual Research Simulator VRESIM is equipped with highest Level D certified flight data for the CRJ-700. The flight and geometrical data of the CRJ-700 were used to quantify the aerodynamic benefits of the CRJ-700 equipped with a morphing winglet versus its reference winglet. The structural design and the mechanism allowing its rotation were used to allow the orientation of the winglet with angles between 90° and -90°. The control of the orientation of the morphing winglet with its mechanism was finally carried out using the Matlab/ Simulink interface. Therefore, a new concept of morphing winglet was obtained in this research.

Morphing Winglet Design for Aerodynamic Performance Optimization of the CRJ-700 Aircraft. Part 1 – Structural Design

This study aims to design a morphing winglet structure for the CRJ-700 regional transport aircraft. The morphing technology is applied on winglets to demonstrate a significant increase of the aerodynamic performance of aircraft. From the aerodynamic data of the LARCASE Virtual Research Simulator VRESIM, the aerodynamic benefits in the cruising phase were obtained through a study on the ParaView software. The morphing winglet design was drawn using CATIA V5; this new concept included several structural components, as well as a simple and light mechanism allowing to orientate the winglet angles between 90° and -90° of inclination. The structural model was exported to HyperMesh structural analysis software. Maximum stresses were obtained, and the model demonstrated its resistance to maximum aerodynamic loads as well as load factors of -2G to 7G.

Comparative Aerodynamic Performance Analysis of Camber Morphing and Conventional Airfoils

This paper aims to numerically validate the aerodynamic performance and benefits of variable camber rate morphing wings, by comparing them to conventional ones with plain flaps, when deflection angles vary, assessing their D reduction or L/D improvement. Many morphing-related research works mainly focus on the design of morphing mechanisms using smart materials, and innovative mechanism designs through materials and structure advancements. However, the foundational work that establishes the motivation of morphing technology development has been overlooked in most research works. All things considered, this paper starts with the verification of the numerical model used for the aerodynamic performance analysis and then conducts the aerodynamic performance analysis of (1) variable camber rate in morphing wings and (2) variable deflection angles in conventional wings. Finally, we find matching pairs for a direct comparison to validate the effectiveness of morphing wings. As a result, we validate that variable camber morphing wings, equivalent to conventional wings with varying flap deflection angles, are improved by at least 1.7% in their L/D ratio, and up to 18.7% in their angle of attack, with α = 8° at a 3% camber morphing rate. Overall, in the entire range of α, which conceptualizes aircrafts mission planning for operation, camber morphing wings are superior in D, L/D, and their improvement rate over conventional ones. By providing the improvement rates in L/D, this paper numerically evaluates and validates the efficiency of camber morphing aircraft, the most important aspect of aircraft operation, as well as the agility and manoeuvrability, compared to conventional wing aircraft.

Study of various trends for morphing wing technology

Term ‘Morphing’ is generally used where the body structurally adapts to make itself best suited for its situation and become more efficient for the same. This phenomenon is seen in nature where species change their body configuration to handle the situation in the best way possible. The same concept is applied on aircraft to make them versatile for various situations, like changing from a long endurance mission to a high speed combat mission. As of now conventional aircraft are best suited for a few mission types, morphing technology seeks to change that. In the current situation morphing is mostly being done on wings and can be categorized in two broad methods. This review discusses and analyzes those methods. Also a comparison is done among them on the basis of structural stability, ease of manufacturing, actuation efficiency and reliability. Finally a summary is given for the current situation of the morphing wing technology and various future scopes for the same.

Passive Morphing in Aerospace Composite Structures

Attempts to add the advanced technologies to aerospace composite structures like fan blade have been on in recent times to further improve its performance. As part of these efforts, it has been proposed that the blade morph feasibility could be studied by building and optimizing asymmetric lay up of composite plies inside the blade which will help generate enough passive morphing between max cruise and climb conditions of the flight. This will have a direct efficiency (Specific Fuel Consumption) benefit. This research describes the various ideas that were tried using in house-developed lay-up optimization code and Ansys commercial software to study the possibility of generating enough passive morphing in the blade. In the end, this report concludes that the required degree of passive morphing could not be generated using various ideas with passive morphing technology and only up to some extent of morphing is shown to be feasible using the technologies used here.

Highly Flexible Wind Turbine Blades Utilizing Corrugated Surface Hinges

An anthropomorphic wind turbine blade was the suggested design that had a flexure hinge at root, middle, and tip regions. The inter-distances of the flexure hinges follow the Fibonacci sequence and resembled the natural finger through binding. Therefore, the present study designs various corrugated flexure hinges. NACA0012 is chosen as the basic airfoil for designing the corrugated flexure hinges with different geometrical profiles and leading edges. The designs are based on morphing technology and the main geometrical parameters of the corrugation, the pitch distance along the span and the height, are inspired by tubercles of the whale flippers. The study uses the finite element method to define the significant strength characteristics of each design flap-wise, edge-wise, torsional stiffness, and buckling resistance in order to assign the best fit corrugation profile for each region of the blade.

Transonic flutter characteristics of an airfoil with morphing devices

An investigation into transonic flutter characteristic of an airfoil conceived with the morphing leading and trailing edges has been carried out. Computational fluid dynamics (CFD) is used to calculate the unsteady aerodynamic force in transonic flow. An aerodynamic reduced order model (ROM) based on autoregressive model with exogenous input (ARX) is used in the numerical simulation. The flutter solution is determined by eigenvalue analysis at specific Mach number. The approach is validated by comparing the transonic flutter characteristics of the Isogai wing with relevant literatures before applied to a morphing airfoil. The study reveals that by employing the morphing trailing edge, the shock wave forms and shifts to the trailing edge at a lower Mach number, and aerodynamic force stabilization happens earlier. Meanwhile, the minimum flutter speed increases and transonic dip occurs at a lower Mach number. It is also noted that leading edge morphing has negligible effect on the appearance of the shock wave and transonic flutter. The mechanism of improving the transonic flutter characteristics by morphing technology is discussed by correlating shock wave location on airfoil surface, unsteady aerodynamics with flutter solution.