Experimental Investigation of Turbulence Diffusion — A Factor in Transportation of Sediment in Open-Channel Flow

Turbulence diffusion in open-channel flow was investigated experimentally by photographing the spread of globules formed by the injection of an immiscible fluid into water. The mean-square transverse deviations of the globules at various distances downstream from the source were computed and analyzed in an effort to determine the shape of the velocity-correlation curve. Comparison was made between two types of curve which fitted the deviation data, one corresponding to a power-correlation law and the other to an exponential-correlation law

Recovery College in Nederland

Niks is zo complex als hulp- en dienstverlening aan multiproblem cliënten. Niet alleen kampen zij met veel problemen, de problemen grijpen ook nog eens in elkaar waardoor er een bijna onontwarbare kluwen ontstaat. Zonder multidisciplinaire samenwerking kom je er niet. Studenten van de specialisatie Recht & Multiproblem ervaren dat in levenden lijve. Een groot deel van de specialisatie brengen ze door in het werkveld, waar ze onderzoeken doen voor organisaties als het Veiligheidshuis, Verslavingszorg Noord Nederland en de leerplichtambtenaar. Deze organisaties werken met multiproblem cliënten. Door deze unieke en nauwe samenwerking bereiden studenten zich optimaal voor op de professionele wereld waar zij in terecht komen na hun studie

A simple eddy viscosity formulation for turbulent boundary layers near smooth walls

The aim of this study is to improve the prediction of near-wall mean streamwise velocity profile $U^+$ by using a simple method. The $U^+$ profile is obtained by solving the momentum equation which is written as an ordinary differential equation. An eddy viscosity formulation based on a near-wall turbulent kinetic energy $k^+$ function (R. Absi, Analytical solutions for the modeled $k$-equation, ASME J. Appl. Mech. \textbf{75}, 044501, 2008) and the van Driest mixing length equation (E.R. van Driest, On turbulent flow near a wall, J. Aero. Sci. \textbf{23}, 1007, 1956) is used. The parameters obtained from the $k^+$ profiles are used for the computation of $U^+$ (variables with the superscript of + are those nondimensionalized by the wall friction velocity $u_\tau$ and the kinematic viscosity $\nu$). Comparisons with DNS data of fully-developed turbulent channel flows for $109 < Re_{\tau} < 2003$ show good agreement (where $Re_{\tau}$ denotes the friction Reynolds number defined by $u_\tau$, $\nu$ and the channel half-width $\delta$)