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...

Steady incompressible flow around a circular cylinder in an external magnetic field that is aligned with fluid flow direction is studied for Re (Reynolds number) up to 40 and the interaction parameter in the range 0 ≤N ≤ 15 (or 0 ≤M ≤ 30), where M is the Hartmann number related to N by the relation M = √2N Re, using finite difference method. The pressure-Poisson equation is solved to find press...

Equations, based on Rayleigh’s drag law valid for high Reynolds number, are derived for two-dimensional motion through a compressible atmosphere in isentropic equilibrium, such as characterizes the Earth’s troposphere. Solutions yield horizontal and vertical displacement, velocity, and acceleration as a function of altitude and ground-level temperature. An exact analytical solution to the equat...

Elegant and inviscid analytical theory can predict the induced drag on lifting wings of finite span. The theoretical prediction is then often modified by multiplication with a dimensionless coefficient for which the departure from a value of 1 is used as a way to incorporate realistic and necessary departures from the idealizedmodel. Unfortunately, there are conflicting definitions of these dim...

Stokes Paradox, Fluid dynamics, Stokes flow, Stream function, Biharmonic equation, Helmholtz equation, Low Reynolds number This paper proposes a solution to Stokes’ paradox for asymptotically uniform viscous flow around a cylinder. The existence of a global stream function satisfying a perturbative form of the two-dimensional Navier–Stokes equations for low Reynolds number is established. This ...

The aerodynamic noise and vibration caused by the vehicle door mirror has been much studied [1], largely by numerical simulation [2]. It is evident that the aerodynamic noise and vibration are strongly associated with the flow structures, and the unsteady behavior of the vortex causes the wind noise. Recently the aero-acoustic characteristics of a vehicle door mirror were also studied by numeri...

The aim of this study was to compare the speed fluctuation and the drag force in young swimmers between genders. Twenty-three young pubertal swimmers (12 boys and 11 girls) volunteered as subjects. Speed fluctuation was measured using a kinematical mechanical method (i.e., speedo-meter) during a maximal 25-m front crawl bout. Active drag, active drag coefficient and power needed to overcome dra...

Wepresentmeasurements of the dissipative turbulent drag on a vibrating grid in superfluid 4He over awide range of (low) frequencies. At high velocities, the dissipative drag is independent of frequency and is approximately the same as that measured in normal liquid 4He. We present measurements on a similar grid in superfluid 3He-B at low temperatures which shows an almost identical turbulent dr...

We propose a reduced-order model for the instantaneous hydrodynamic force on a cylinder. The model consists of a system of two ordinary differential equations (ODEs), which can be integrated in time to yield very accurate histories of the resultant force and its direction. In contrast to several existing models, the proposed model considers the actual (total) hydrodynamic force rather than its ...

A simple expression is derived of the componential contributions that different dynamical effects make to the frictional drag in turbulent channel, pipe and plane boundary layer flows. The local skin friction can be decomposed into four parts, i.e., laminar, turbulent, inhomogeneous and transient components, the second of which is a weighted integral of the Reynolds stress distribution. It is r...