Every aircraft currently crossing the sky are using fossil fuels in order to generate the propulsion required to fly, which leads to the production of carbon dioxide and other greenhouse gases that warm the environment. Having this in mind, the main drive for the next generation of aircraft is fuel efficiency. One of the solutions that is being tested to increase the fuel efficiency is the intr...

Competition is one of the most cited mechanisms to explain secondary sexual dimorphism in animals. Nonetheless, it has been proposed that sexual dimorphism in bat wings is also a result of adaptive pressures to compensate additional weight caused by fetus or pup carrying during the reproductive period of females. The main objective of this study is to verify the existence of sexual dimorphism i...

Flapping-wing robotic platforms based on Dipteran insects have demonstrated lift to weight ratios greater than 1, but research into regulating the aerodynamic forces produced by their wings has largely focused on active wing trajectory control. In an alternate approach, a flapping-wing drivetrain design that passively balances aerodynamic drag torques is presented. A discussion of the dynamic p...

In this work, the aerodynamic performance of beetle wing in free-forward flight was explored by a three-dimensional computational fluid dynamics (CFDs) simulation with measured wing kinematics. It is shown from the CFD results that twist and camber variation, which represent the wing flexibility, are most important when determining the aerodynamic performance. Twisting wing significantly increa...

Data collected in 2012 on 400 chickens were subjected to two-way analyses of variance to estimatebody weight, morphometric traits as well as the correlationbetween body weight and morphometric traitsin Isa Brown and Ilorin ecotypechickens. The studied morphometric traits were comb length, beak length,head length, neck length, body length, wing length, shank length, thigh length, toe length, bre...

Limits to flight performance at high altitude potentially reflect variable constraints deriving from the simultaneous challenges of hypobaric, hypodense and cold air. Differences in flight-related morphology and maximum lifting capacity have been well characterized for different hummingbird species across elevational gradients, but relevant within-species variation has not yet been identified i...

The undersigned hereby certify that they have read and recommend to the Faculty of Aerospace Engineering for acceptance a thesis entitled " Aeroelastic Roll Control for High Aspect Ratio Wings " Summary Modern aircraft tend to be light and slender. The high aspect ratio reduces the induced drag, increase fuel efficiency, and provide enough lift at low speeds. Therefore such wing types are used ...

A preliminary study of structural concepts for noncircular fuselage configurations is presented. For an unconventional flying-wing type aircraft, in which the fuselage is inside the wing, multiple fuselage bays with non-circular sections need to be considered. In a conventional circular fuselage section, internal pressure is carried efficiently by a thin skin via hoop tension. If the section is...

We describe the design of four ornithopters ranging in wing span from 10 cm to 40 cm, and in weight from 5 g to 45 g. The controllability and power supply are two major considerations, so we compare the efficiency and characteristics between different types of subsystems such as gearbox and tail shape. Our current ornithopter is radio-controlled with inbuilt visual sensing and capable of takeof...

A slowed-rotor compound helicopter has been synthesized using the NASA Design and Analysis of Rotorcraft (NDARC) conceptual design software. An overview of the design process and the capabilities ofNDARC are presented. The benefits of trading rotor speed, wing-rotor lift share, and trim strategies are presented for an example set of sizing conditions and missions. NOMENCLATURE Acronyms DGW Desi...