TITLE : STUDY OF A FLOW IN A WATER DISTRIBUTOR

BY : S Zhubrin - CHAM-MEI, E Lopez - INP-Grenoble

Date: 1997 PHOENICS Version: 3.0

DETAILS :

• The case is three dimensional, and the flow is steady.

• The geometry within the domain was created using PHOENICS-VR.

• Objects like pipes and cylinders and wedges which were required for this case were placed on a Cartesian grid using ASAP, the Abitrary Source Allocation Procedure found in PHOENICS.

• The water distributor is four meters high, the mass inflow rate ranged from 160 kg/s to 400 kg/s. The water flows entered on one side of the distributor through a bent pipe and the water flows over weirs into four separate chambers.

• The water distributor is completely open at the top and so the free surface had to be modelled. The sides of the distributor were weirs and an easy and sufficient way to simulate the outlet boundary condition, and hence the height of the FREE SURFACE, was to implement the formula:

                              q=c*h*(gh)**(1/2).
  

  This formula governs the water level at the weirs where the outlets are located, and here

          q - flow rate per unit width or weir
          h - is the height of the fluid above the weir
          g - is the acceleration of gravity
          c - overflow coefficient
  

• The LVEL model of turbulence is used to close the Reynolds-averaged Naviers-Stokes equations.

• PLANT was used to insert the GROUND codings necessary to set the outlet boundary condition.

• Unequal flow distribution was predicted by PHOENICS at the the outlets due to horizontal momentum of the incoming fluid and the curvature of the inlet pipe. This was also shown by experiment.

The following illustrates the geometry and velocity results.

Geometry created by VR and using ASAP.(Some objects were removed for viewing)
A view of the inlet and curved pipe created by VR and ASAP.
Velocity distribution at the distributor outlet.

wbs