Low Reynolds number aerodynamics is important for various applications including micro-aerial vehicles, sailplanes, leading edge control devices, high-altitude unmanned vehicles, wind turbines and propellers. These flows are generally characterized by the presence of laminar separation bubbles. These bubbles are generally unsteady and have a significant effect on the overall resulting aerodynam...

This paper will present the large eddy simulation of turbulence modeling for wind flow over a wall mounted 3D cubical model. The LES Smagorinsky scheme is employed for the numerical simulation. The domain for this study is of the size of 60 cm x 30 cm x 30 cm. The 3D cube model is taken of the size of 6 cm x 6 cm x 4 cm. The Reynolds number for the flow in respect of the height of the cube i.e,...

The γ-Reθ-model, a two equation, correlation-based transition model using local variables, has been employed to predict the extension of the laminar regions on a stiff geometry of the common dolphin (delphinus delphis) moving in the Reynolds regime of 5.5 ·10 to 10. Mesh independence was gained for a domain resolution of approximately 30 million cells in an unstructured polyhedral mesh with a p...

The measurement and prediction of the aerodynamic performance of airfoils and wings at chord Reynolds numbersbelow105 arebothdifficult and increasingly important in the application to small-scale aircraft.Not only are the aerodynamics strongly affected by the dynamics of the unstable laminar boundary layer, but the flow is decreasingly likely to be two-dimensional as theReynolds number decrease...

Previous studies on the sound attenuation in particle-laden flows under Stokesian drag and conduction-controlled heat transfer have been extended to accommodate the nonlinear drag and heat transfer. It has been shown that for large particle-to-fluid density ratio, the particle Reynolds number bears a cubic relationship with omegatau(d) (where omega is the circular frequency and tau(d) is the St...

• Obtain predictive models for the drag coefficient of a sphere using symbolic regression. The depends on logarithmic terms Reynolds number. have higher extrapolation range than power-based models. can predict crisis at high numbers. proper behaviour low number regime. At beginning second half twentieth century, Proudman and Pearson (J. Fluid. Mech.,2(3), 1956, pp.237-262) suggested that functi...

In the present investigation, slip-continuum and molecular (DSMC) flow models have been used to compare the drag coefficient on a confined microsphere over a range of Knudsen numbers between 0.01 and 0.4. The simulations consider a fixed Reynolds number (Re=0.125) and a range of blockage ratios from 2.0 up to 13.0. Two separate problem formulations have been studied; the first considers flow pa...

Flat plate skin friction calculations over a range of Mach numbers from 0.4 to 3.5 at Reynolds numbers from 16 million to 492 million using a Navier Stokes method with advanced turbulence modeling are compared with incompressible skin friction coefficient correlations. The semi-empirical correlation theories of van Driest; Cope; Winkler and Cha; and Sommer and Short T’ are used to transform the...