Problem data

Once the boundary conditions have been assigned, we have to specify the other parameters of the problem. These have to be entered in the Tdyn Problem and Solver Data window (Figure 18). Several data as the time increment for every time step and problems to be solved can be defined through this window.

  

Figure 18 Problem Data menu and icon

Note that after entering or changing parameters in the Tdyn Problem and Solver Data window the Accept Data button has to be pressed.

In our case the only data that have to be changed are in the PROBLEM (see final values in Figure 19), ANALYSIS and RESULTS tags.

Figure 19. Tdyn Problem and Solver Data window
PROBLEM tag options

Figure 20. Tdyn Problem and Solver Data window
ANALYSIS tag options

Through the Tdyn Problem and Solver Data window it is also possible to define solver properties (see FLUID SOLVER and SOLID SOLVER tags) and symmetry planes (see OTHER tag) for example. These options will not be changed in this example.

Figure 21. Tdyn Problem and Solver Data window
RESULTS tag options

Following are explanations of the most useful options:

Option

Meaning

Number of Steps

Number of steps of the simulation. Total time of the simulation will be  (Number_of_Steps X Time_increment).

Max Iterations

Maximum number of iterations of the non-linear fluid scheme (recommended values 1-3).

Time increment

Time increment for each time step (recommended values < 0.1 * Length / Velocity).

Output Step

Each Output_Steptime steps the results will be written.

Output Start

Results will be written after Output_Starttime steps.

 

Figure 22 gives a brief summary of the boundary conditions, boundary definitions and material properties that have been applied to the control domain.

Condition

Entity

Fix Velocity

Line 3

Fluid Body

Line 1, 2, 4

Fluid

Surface 1

Fix Pressure

Point 1

Figure 22 Overview of the applied conditions