In this work, a numerical analysis of the flow over a stepped spillway is performed. The free surface flow is described by the Reynolds Averaged Navier-Stokes equation (RANS) coupled to k-ε model. These equations are solved using a commercial software based on the finite volume scheme and the VOF method. We analyzed the influence of the steps shape and water flow rate on velocity, turbulence dissipation rate and pressure distributions. In this, we found that the maximum values of the static pressure and the turbulence dissipation rate increase as the discharge increases and the main flow velocity is greater than the one of the secondary flow.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Turbulent heat transfer in a vertical channel with discrete heat wall source has been studied numerically. Three different cases were tested according to the heated part of the channel wall. In the first case the flux is applied on the left wall and at the top and the bottom of the right wall separated by an adiabatic zone. The second case, the flux is applied on a zone located on the middle of the left wall and the flux conditions are identical to the first case and in the third case, the right wall is soaked with water. Transfer equations associated to the Launder and Sharma low Reynolds number k-s model are solved using the finite volume method, Thomas and Gauss algorithms. Effects of heat flux density and Reynolds numbers on velocity, air and wall temperature, eddy viscosity, Nusselt and Sherwood numbers were investigated. From these results the driven buoyancy flow for low Reynolds numbers and great Rayleigh numbers affects substantially transfers along the channel. The adiabatic zone influences substantially heat and mass transfer along the channel.
3
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The objective of this work is the developement and assessment of a fourth-order compact scheme for the three-dimensional unsteady incompressible viscous flows. The equations of the flow are discretized on a staggered grid and using fourth-order compact scheme for the three directions. The accuracy of the method is demonstrated in the Taylor-Green vortex problem. Finally, the turbulent natural convection in a vertical channel is investigated to validate the numerical methods.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.