3D staggered grid turbulent flow modeling in sewer net pipe
Résumé
There are two kinds of turbulance model : first and second order. The first kind closes the system of Reynolds mean flow equations, the second closes Reynolds stress transport equations. This article deals with the description of a k-epsilon model (first-order closure model) and a Reynolds stress model (second-order closure model) for the numerical simulation of uniform 3D turbulent open-channel flows. A precise flow modeling needs to be implemented in a code designed for sewer net conduit. A 2D mesh is used to calculate 3D velocity flow which is less time consumer. Velocity profile and flow rate computed by the two models are compared. The aim is the intepolation of a mean flow stream from discreet data supplied by a Doppler velocimeter or an ultrasonic velocity profile meter. A quite good velocity profile is provided by the two models but the Dip phenomenon is only predicted by RSM. Regarding the flow rate, there is a better agreement with empiric law for the RSM.