Page 187 - TransAT_Tutorial_Manual

TransAT Tutorial Manual 4.5. Spillway

We can define water phase for the backflow, so whenever the flow is reversed, water will enter
the domain. This is a kind of trick here, since we do not know what would be the velocity at the
inlet boundary condition and by using backflow condition this problem is resolved automatically.
However by imposing a backflow we are not able to control water level, so it is presumed the
water level is not affected far away from the spillway.

• Rename the Outflow BC to inflowWater

• Click to set the boundary condition properties
• Fill in the outflow properties:

– In the Basic tab

∗ Outflow Type: Pressure
∗ OutflowData Source: From Initial Conditions

– In Backflow properties tab:
∗ Backflow turbulent intensity: 0.1
∗ Backflow eddy viscosity ratio: 100.0
∗ Backflow volume fraction of phase 2: 1.0 (water only)

• Click

• A second outflow is required. Click to create this.
• Rename the created BC to inflowAir and change the type to Outflow in the drop-down.

• Click to edit the outflow properties
Name: inflowAir
Type : Outflow
General p r o p e r t i e s :
− Outflow Type : Pressure
− Outflow Data Source : From I n i t i a l conditions
Backflow p r o p e r t i e s :
− Backflow Volume Fraction of Phase 1: 1.0 ( a i r )
− Backflow turbulent i n t e n s i t y : 0.1
− Backflow eddy v i s c o s i t y r a t i o : 100.0

Name: Wall
Type : Wall

Name: Symmetry
Type : Symmetry

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