During slow flight, bird species vary in their upstroke kinematics using either a 'flexed wing' or a distally supinated 'tip-reversal' upstroke. Two hypotheses have been presented concerning the function of the tip-reversal upstroke. The first is that this behavior is aerodynamically inactive and serves to minimize drag. The second is that the tip-reversal upstroke is capable of producing signi...

This paper discusses two adaptive feedback control approaches designed to reattach a massively separated flow over a NACA airfoil with minimal control effort using piezoelectric synthetic jet actuators and various sensors for feedback. One approach uses an adaptive feedback disturbance rejection algorithm in conjunction with a system identification algorithm to develop a reduced-order dynamical...

An analysis is performed to study the supersonic flow over conical bodies of three different cross sections circular, elliptic and squircle (square with rounded corners) shaped. Perturbation method is applied to find flow variables analytically. In order to find lift and drag forces the pressure force on the body is found, the component along x is drag and the component along z is lift. Three e...

Numerical investigation was performed on NACA 0015 which is a symmetric airfoil. Pressure distribution and then lift and drag forces are verified. Changing of ground clearance was a considerable point. Also the angle of attack was changed from 0° to 10°. Pressure coefficient reaches its higher amounts on the wing lower surface when the ground clearance diminishes. Increment of the angle of atta...

Abstract Studying the effect of leading-edge parameters 30P30N on aerodynamic characteristic was carried out. Effect changing gap and overlap slat airfoil were mainly investigated. Numerical simulation applied to obtain characteristics, results show that: lift coefficient in linear segment basically does not change with gap, drag decreases gap. The have obvious lift-to-drag ratio. smaller betwe...

A wingsuit is a special suit that is worn to allow the user to fly after jumping off of a high cliff. The wingsuit creates an airfoil shape by adding wings of material between the arms and the sides as well as a tail consisting of material between the legs. The wingsuit allows for the creation of lift and thus human flying. A new and novel wingsuit design is proposed based on the design of a de...

Recent studies have demonstrated that a quasi-steady model closely matches the instantaneous force produced by an insect wing during hovering flight. It is not clear, however, if such methods extend to forward flight. In this study we use a dynamically scaled robotic model of the fruit fly Drosophila melanogaster to investigate the forces produced by a wing revolving at constant angular velocit...

A procedure for tailoring a blended wing-body con guration to reduce its computed wave drag is described. The method utilizes an iterative algorithm within the framework of rst-order linear theory. Four computed examples are included. In each case, the zero-lift wave drag was reduced without an increase in drag due to lift. Introduction In the initial rough-cut state of supersonic conguration d...

Limpets are commonly found on wave-swept rocky shores, where they may be subjected to water velocities in excess of 20 m s(-1). These extreme flows can impose large forces (lift and drag), challenging the animal's ability to adhere to the substratum. It is commonly thought that the conical shape of limpet shells has evolved in part to reduce these hydrodynamic forces while providing a large ape...