A human can lift up an object with almost minimal grasping force regardless of the fiction coefficient between the fingers and the object, but the sensing mechanism for this remarkable task has not been well explicated yet. In this paper we propose a tactile sensor to detect a fiction coefficient at the moment of touch. With this sensor output we evaluate the largest lifting-force just before a...

In this study, surface features such as dimples and bumps are introduced to the of a NACA 0012 airfoil study their effect on boundary layer separation, particularly at high angles attack. Six modified airfoils were designed with spherical pyramidical shapes. A computational fluid dynamics (CFD) analysis was conducted these models subsonic flow using Ansys Fluent. The used Shear Stress Transport...

in this paper, the effect of electric field on two-dimensional low reynolds air flow around an airfoil and variation of the forces acting on the airfoil is numerically investigated. the electric current and poisson’s equations are solved and the outcome is considered as a source term in the momentum equations. the energy equation is not considered due to its weak effect on the phenomena. the fi...

This paper deals with the numerical simulation of the twodimensional, incompressible, steady air flow past an airfoil for a solar powered unmanned aerial vehicle (UAV) with internal propulsion system. This airfoil results from a NACA 2415 four digits family base airfoil modification [7] and has a propulsive outlet with the shape of a step on the suction surface. The analysis involved the airfoi...

A prominent feature of gliding flight in snakes of the genus Chrysopelea is the unique cross-sectional shape of the body, which acts as the lifting surface in the absence of wings. When gliding, the flying snake Chrysopelea paradisi morphs its circular cross-section into a triangular shape by splaying its ribs and flattening its body in the dorsoventral axis, forming a geometry with fore-aft sy...

background  many biomaterials are used during the open sinus lift surgery, beneath the elevated scheniderian membrane and maxillary sinus bony floor but the search for ideal material continues. methods  in the maxillary posterior atrophic ridges with the bone height less than four millimeters the open sinus lift surgery performed. the autologous platelet-rich plasma (prf) was used as the sole g...

1. Abstract This paper deals with the optimization of shape of aerodynamic profiles. The objective is to reduce the drag coefficient on a given airfoil while preserving the lift coefficient within acceptable ranges. A set of control points defining the geometry are passed and parameterized as a B-Spline curve. These points are modified automatically by means of CFD analysis. A given shape is de...

Chrysopelea paradisi, also known as the flying snake, possesses one of the most unique forms of aerial locomotion found in nature, using its entire body as a dynamic lifting surface without the use of wings or membranes. Unlike other airborne creatures, this species lacks appendages to aid in controlling its flight trajectory and producing lift. The snake exhibits exception gliding and maneuver...

The morphology and kinematics of a flying animal determines the resulting aerodynamic lift through the regulation of the speed of the air moving across the wing, the wing area and the lift coefficient. We studied the detailed three-dimensional wingbeat kinematics of the bat, Leptonycteris yerbabuenae, flying in a wind tunnel over a range of flight speeds (0-7 m/s), to determine how factors affe...

The relationship between lateral static stability derivative, Clβ , lift coefficient, CL, and angle of attack was investigated for rectangular wings of aspect ratioA= 0.75,1,1.5, and 3 using Stereo-Digital Particle Image Velocimetry (S-DPIV) and direct force and moment measurements. When the product ClβA is plotted with respect to CL, the lateral stability curves of each wing collapse to a sing...