Aircraft wings are a compromise that allows the aircraft to fly at a range of flight conditions, but the performance at each condition is sub-optimal. The ability of a wing surface to change its geometry during flight has interested researchers and designers over the years as this reduces the design compromises required. Morphing is the short form for metamorphose; however, there is neither an exact definition nor an agreement between the researchers about the type or the extent of the geometrical changes necessary to qualify an aircraft for the title ‘shape morphing.’ Geometrical parameters that can be affected by morphing solutions can be categorized into: planform alteration (span, sweep, and chord), out-of-plane transformation (twist, dihedral/gull, and span-wise bending), and airfoil adjustment (camber and thickness). Changing the wing shape or geometry is not new. Historically, morphing solutions always led to penalties in terms of cost, complexity, or weight, although in certain circumstances, thes...

A Review of Morphing Aircraft

Recent progress in flapping wing aerodynamics and aeroelasticity

Classifications, applications, and design challenges of drones: A review

Mechanics of mechanically fastened joints in polymer–matrix composite structures – A review

Uncertainties and dynamic problems of bolted joints and other fasteners

* An Overview of Micro Air Vehicle Development * Elements of Aerodynamics, Propulsion, and Design * Autopilot Integration into Micro Air Vehicles * Case Study: The Micro Tactical Expendable (MITE) Rigid-Wing Micro Air Vehicle * Case Study: Flexible Wing Micro Air Vehicles * Case Study: Development of Micro Air Vehicles with In-Flight Adaptive Wing * Summary.

Introduction to the design of fixed-wing micro air vehicles : including three case studies

The research and development efforts outlined in this paper address the aerodynamic design of micro air vehicles with hovering and vertical takeoff and landing capabilities. The tilt-body configuration of the vertical takeoff and landing micro air vehicle is proposed based on a propulsion system consisting of two coaxial contrarotating motors and propellers. Values of thrust, torque, power, and efficiency of this propulsion system were measured in pusher and tractor arrangements of propellers and compared against single motor-propeller propulsion. With comparable efficiency, the developed propulsion system has very little propeller torque. Hot-wire measurements have been conducted to investigate the velocity profile in slipstream. The lower average velocity and significant decrease in velocity in the core of the slipstream found in the tractor arrangement are mostly due to the parasite drag caused by the motors. It causes the decrease of the thrust force observed for the tractor arrangement in comparison with the pusher arrangement. Wind-tunnel testing was conducted for a motor, a wing, and an arrangement of a wing with a motor. The drag force on the wing is produced by two mixing airflows: freestream and propeller-induced pulsating slipstream. The zero-lift drag coefficient increases by about 4 times with propeller-induced speed increased from 0 to 7.5 m/s. The results of this study were realized in the design of a vertical takeoff and landing micro air vehicle prototype that was successfully flight tested.

Aerodynamic Design of Micro Air Vehicles for Vertical Flight

An important and challenging technology aimed at the next generation of aerospace vehicles is that of structural health monitoring. The key problem is to determine accurately, reliably, and in real time the applied loads, stresses, and displacements experienced in flight, with such data establishing an information database for structural health monitoring. The present effort is aimed at developing a finite element-based methodology involving an inverse formulation that employs measured surface strains to recover the applied loads, stresses, and displacements in an aerospace vehicle in real time. The computational procedure uses a standard finite element model (i.e., direct analysis ) of a given airframe, with the subsequent application of the inverse interpolation approach. The inverse interpolation formulation is based on a parametric approximation of the loading and is further constructed through a least-squares minimization of calculated and measured strains. This procedure results in the governing system of linear algebraic equations, providing the unknown coefficients that accurately define the load approximation. Numerical simulations are carried out for problems involving various levels of structural approximation. These include plate-loading examples and an aircraft wing box. Accuracy and computational efficiency of the proposed method are discussed in detail. The experimental validation of the methodology by way of structural testing of an aircraft wing is also discussed.

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An Inverse Interpolation Method Utilizing In-Flight Strain Measurements for Determining Loads and Structural Response of Aerospace Vehicles

The research and development efforts presented in this paper address the flight dynamics of a flapping-wing air vehicle (ornithopter). The 74-cm-wing-span ornithopter was equipped with an automatic flight control system that provides stability augmentation and navigation of the vehicle and flight data acquisition. Wind tunnel tests were conducted with the control surfaces fixed in the trimmed position and flapping motion of the wings activated by a motor at a constant throttle setting. Coefficients of vertical and horizontal force, and pitching moment were determined at a free stream velocity of 7.25 m/sec, and the angle of the stroke plane varied from 0 to 40 degrees. A series of flight tests were conducted with fixed controls, demonstrating ornithopter stability in all axes. Proportional control laws were programmed into the autopilot for the closed-loop controls. A number of flights of the autonomous ornithopter were conducted with the telemetry acquisition. During the autonomous flights, the ornithopt...

https://journals.sagepub.com/doi/pdf/10.1260/1756-8293.1.1.35

Flight Dynamics of a Flapping-Wing Air Vehicle

Four microair vehicle wind-tunnel models were built with 3, 6, 9, and 12% camber, all based upon the S5010-TOP24C-REF thin, cambered-plate airfoil. These models were tested in the Low Speed Wind Tunnel at angles of attack ranging from 0 to 35 deg and velocities of 5, 7.5, and 10 m/s, corresponding to mean aerodynamic chord Reynolds numbers of 5 × 10 4 , 7.5 × 10 4 , and 1 x 10 5 , respectively. Aerodynamic coefficients C L , C D , C M and lift-to-drag ratio (LID) were obtained and plotted vs angle of attack for all of the cambers at each velocity

Sergey Shkarayev

Papers

Introduction to the design of fixed-wing micro air vehicles : including three case studies

Aerodynamic Design of Micro Air Vehicles for Vertical Flight

An Inverse Interpolation Method Utilizing In-Flight Strain Measurements for Determining Loads and Structural Response of Aerospace Vehicles

Flight Dynamics of a Flapping-Wing Air Vehicle

Effect of camber on the aerodynamics of adaptive-wing micro air vehicles