Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1-2% of chord length on the upper surface--10,000 times rougher than sailplane wings. Sailplanes depend on extreme wing smoothness to increase the area of laminar flow on the win...

We study the dynamics and properties of a turbulent flame, formed in the presence of subsonic, high-speed, homogeneous, isotropic Kolmogorov-type turbulence in an unconfined system. Direct numerical simulations are performed with Athena-RFX, a massively parallel, fully compressible, high-order, dimensionally unsplit, reactive-flow code. A simplified reaction-diffusion model represents a stoichi...

A novel numerical scheme has been developed to simulate high speed viscous flows in complex geometries using unstructured grids. A characteristic–filter based shock capturing scheme is applied as a corrector step to a non–dissipative predictor scheme. This algorithm is being used to study shock turbulent boundary layer interactions and this paper presents the results of a turbulent flow at Mach...

Tangential and normal velocity profiles of the boundary layer surrounding live swimming fish were determined by digital particle tracking velocimetry, DPTV. Two species were examined: the scup Stenotomus chrysops, a carangiform swimmer, and the smooth dogfish Mustelus canis, an anguilliform swimmer. Measurements were taken at several locations over the surfaces of the fish and throughout comple...

A turbulent-laminar banded pattern in plane Couette flow is studied numerically. This pattern is statistically steady, is oriented obliquely to the streamwise direction, and has a very large wavelength relative to the gap. The mean flow, averaged in time and in the homogeneous direction, is analysed. The flow in the quasi-laminar region is not the linear Couette profile, but results from a non-...

An experimental study of static and dynamic pressure distributions over a NACA 0012 airfoil in the two-dimensional test section 0.8 × 0.4-meter of a transonic wind tunnel is presented. Tests are conducted at freestream Mach numbers from 0.35 to 0.89, and angle of attack between −2.0 and 15, and Reynolds number based on the airfoil chord length of 3.0 million. Tests are performed at boundary-lay...

Please cite this article in press as: M. Sankar et a Mass Transfer (2012), http://dx.doi.org/10.1016 Double-diffusive convection in a vertical annulus filled with a fluid-saturated porous medium is numerically investigated with the aim to understand the effects of a discrete source of heat and solute on the fluid flow and heat and mass transfer rates. The porous annulus is subject to heat and m...

The frequency dependence of the phase field model(PFM) is studied. A simple PFM is proposed, and is tested in a laminar boundary layer. The Blasius’s laminar boundary layer solution on a flat plate is used for the flow pattern, and several frequencies are imposed on the PFM, and the decay times of the interfaces are obtained. The computations were conducted for three cases: 1) no-flow, and 2) a...

This paper investigates the characteristics of wall pressure fluctuations in naturally developing boundary layer flows on axisymmetric bodies experimentally. The axisymmetric body has a modified ellipsoidal blunt nose. Flush-mounted microphones are used to measure the wall pressure fluctuations in the boundary layer flow over the body. The measurements are performed in a low noise wind tunnel. ...