nowadays, we live in a world which quality, speed, accuracy and cost are the most important parameters in parts' design and manufacturing. due to the complexity of part manufacturing, traditional and nontraditional manufacturing techniques are used. aerodynamic tests usually requires one or several models for testing in wind tunnels and these models typically have particular complexities in whi...

The morphology, kinematics and stiffness properties of lifting surfaces play a key role in the aerodynamic performance of vertebrate flight. These surfaces, as a result of their flexible nature, may move both actively, owing to muscle contraction, and passively, in reaction to fluid forces. However, the nature and implications of this fluid-structure interaction are not well understood. Here, w...

Unsteady flow and heat transfer from a circular cylinder in cross-flow is studied numerically. The governing equations are solved by using finite volume method. Reynolds number varies in range of 50 to 200; in this range flow is considered to be laminar and unsteady. Al2O3 nanoparticle with volume fraction in range of 5% to 20% is added to pure water. Effects of adding nanoparticle to pure wate...

Results are reported of an experimental investigation into the motion of a heavy cylinder free to move inside a water-filled drum rotating around its horizontal axis. The cylinder is observed to either co-rotate or, counter-intuitively, counter-rotate with respect to the rotating drum. The flow was measured with particle image velocimetry, and it was found that the inner cylinder significantly ...

In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: Abstract A transversely oscillating cylinder in a uniform flow is modeled to investigate frequency effects of flow-induced w...

The flow mechanism leading to the enhanced performance of a discrete co-flow jet (dCFJ) airfoil is investigated. Flow visualization and DPIV are used to analyze the difference between the flow along discrete jets and over the tabs used for discretization of the slot jet. Results show that the entrainment is uniform over the leading jet as long as the tab size is small enough. The jets expand sp...

Gliding flight performance and wake topology of a common swift (Apus apus L.) were examined in a wind tunnel at speeds between 7 and 11 m s(-1). The tunnel was tilted to simulate descending flight at different sink speeds. The swift varied its wingspan, wing area and tail span over the speed range. Wingspan decreased linearly with speed, whereas tail span decreased in a nonlinear manner. For ea...

The purpose of this study is to improve the aerodynamic performance of wind turbine blades, using the Ball-Spine inverse design method. The inverse design goal is to calculate a geometry corresponds to a given pressure distribution on its boundaries. By calculating the difference between the current and target pressure distributions, geometric boundaries are modified so that the pressure di...

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...