High speed wind tunnels are widely used in the study of fluid flow behavior around various objects. The air flow in the starting step of supersonic wind tunnels is transient including strong shock waves caused by the interaction of the tunnel main stream and the boundary layer at walls. To arrive in running step, the tunnel must be designed so as these waves leave immediately the test section. ...

waterwheels are the oldest types of hydraulic machines. these turbines are of relatively simple design, large diameter, low rotational speed and high torques. but applying them as micro hydros of high speed and small diameter is yet to be explored. a micro hydro waterwheel of one meter diameter was designed and manufactured at the iranian  esearc†h organization for science and technology (irost...

The behavior of a variational multiscale LES model is studied for flows past bluff bodies. The circular cylinder is studied for a Reynolds 3900. Subgrid scale eddy viscosities of Smagorinsky, Vreman and the WALE model are compared. The vortex induced motion of a spar equipped with strakes and flexible mooring is then computed. The interest of variational multi-scale as compared to usual Large E...

Flow jets containing velocities up to 5-7 m/s are common in patients with congenital defects and patients with valvular disease (stenosis and regurgitation). The quantitation of peak velocity and flow volume in these jets is clinically significant but requires specialized imaging sequences. Conventional 2DFT phase contrast sequences require lengthy acquisitions on the order of several minutes. ...