Page 74 - TransAT_Tutorial_Manual

TransAT Tutorial Manual 2.2. Flow over a group of Buildings

Simulation Parameters
This tab is used to define the numerical parameters of the simulation.

• Click Simulation Parameters on the left-hand side of the TransATUI

• Set the following parameters to solve for an unsteady flow.
Simulation Type : Unsteady
Time Scheme : Euler 1 st Order
Control Parameters :
Total simulation time : 20 [ s ]
Max Number of Time Steps : 100
I n i t i a l time step : 0.2 [ s ]

Autorelaxation : 0.8

• For Time Stepping select Adaptive then click

• Set the following parameters in the Adaptive Time-Stepping window then click to save
the settings and close the window

CFL Limits Min : 0.5 Max: 1.0
D i ff u s i o n Min : 1.0 Max: 2.0

Equations
In the Equations section, the convergence threshold is defined, as well as the convection scheme
and other parameters of the solvers used by TransAT.

• Select Pressure in the Equation tree

• Set the Convergence Tolerance value to the following
Convergence Tolerance : 1.0 e−3

• Choose the following solver
Solver : AMG, R−cycle Adaptive

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Ascomp AG Switzerland 64 Version 5.7