Reduction of the aerodynamic noise generated by pantographs is a matter of great important for further speedup of the high speed trains. In general, pantographs are composed of some kind of bluff bodies. Therefore, the method to reduc e the aerodynamic noise generated by bluff bodies is demanded. In this paper, we will present the noise reduction effect of cylinder by equipping intermittent hol...

BACKGROUND Unexpected performance degradation occurs in wind turbine blades due to leading edge defect when suffering from continuous impacts with rain drops, hails, insects, or solid particles during its operation life. To assess this issue, this paper numerically investigates the steady and dynamic stall characteristics of an S809 airfoil with various leading edge defects. More leading edge d...

In the current study, twin wind blades are designed, fabricated and the effect of various gap ratio (g*) at various angle of attacks (α) on a next to each other twin wind blades are examined in an open-channel wind tunnel. Aerodynamic forces and moments are determined by using three-constraint force balancer. For gap ratio of zero, the aerodynamic attributes are like those of a solitary wind bl...

This study investigated the performance and aeroelastic characteristics of a wind turbine blade based on strongly coupled approach (two-way fluid structure interaction) to simulate the transient FSI1 responses of HAWT2. Aerodynamic response was obtained by 3D CFD-URANS approach and structural response was obtained by 3D Finite element method. Aeroelastic responses of the blade were obtained by ...

An interesting characteristic of avian gliders is their ability to soar or remain aloft without flapping their wings for long periods. There are two ways to do this. In static soaring a bird maintains or gains altitude by gliding in air that has an upward velocity component equal to or greater than the bird's sinking speed. In dynamic soaring a bird uses changes in the horizontal wind-velocity ...

We used a combination of high-speed 3-D kinematics and three-axis accelerometer recordings obtained from cockatiels flying in a low-turbulence wind tunnel to characterize the instantaneous accelerations and, by extension, the net aerodynamic forces produced throughout the wingbeat cycle across a broad range of flight speeds (1-13 m s(-1)). Our goals were to investigate the variation in instanta...

this paper presents the aerodynamic design and economical evaluation of a 200 kw site specific wind turbine for the province of semnan in iran. by designing site specific wind turbines, the cost of energy which is calculated out of the annual energy production and also the cost of manufacturing the rotor are minimized. the aerodynamic design is based on the well-known blade element momentum the...