[Example 1] Tracer transport in a straight channel¶
Flow calculation by Nays2DH¶
Select a solver¶
In the [iRIC start page] , select [Create New Project], and when the [Select Solver] screen appears, choose [Nays2DH iRIC 3.x 1.0 64bit] and click [OK] button.
A windows with “Untitled - iRIC 3.x.xxxx [Nays2DH iRIC3X 1.0 64bit]” appears as Figure 10.
In the [Select Grid Creating Algorithm] window, select [Simple Straight and Meandering Channel Creator] and click [OK] (Figure 12).
Setting of calculation conditions for flow by Nays2DH¶
The next step is to set the calculation conditions. From the menu bar, select [Calculation Conditions]->[Settings], then the [Calculation condition setting window] as Figure 16 appears.
As Figure 17, in the [Group] of the [Boundary Condition], click [Edit] at the [Time series of discharge at upstream and water level at downstream]. Then the [Time series of discharge at upstream and water level at downstream] appears as Figure 18 ．
In Figure 18, input [Time] and [Discharge] values, and click [OK] when you finish, and close this window.
Select [Time] and set parameters as Figure 19 and click [Save and Close].
Flow calculation run by Nays2DH¶
From the main menu, when you select [Simulation]->[Run], you will get the message like “We recommend you to save the project before running solver. Do you want to save?” Select [Yes] and save the project with an appropriate name. At this time, do not save the project as an ipro file, but save it as a project. A window as Figure 20 is shown during the computation, and Figure 21 appears when the computation is finished. Then press [OK], and the computation is completed.
Important Whenever you finished the computation, select [File]->[Save] from the menu bar to save the results as Figure 22 . This result is important for later analysis by UTT.
Visualization of the calculated results¶
After the calculation, select [Calculation Result] -> [Open New 2D Post-processing Window] to open the visualization window.
In the [Object Browser], put check marks in the boxes by [Arrow] and [Velocity], click Focus on [Arrow] and click the right mouse button [Properties]. Vector setting” window as Figure 24 appears. Set the values in the red line and click [OK]. Figure 25 is the depth-averaged velocity vector. Here, the velocity distribution is uniform under the constant flow condition.
Display Particle Movement¶
Uncheck “Vectors” in the Object Browser, and put check marks in “Particles” and “Velocity” ( Figure 26 )
Right click [Particle] and select [Properties] as Figure 27 .
Set parameters for particle injection as shown in red box in Figure 28 .
As shown in Figure 29 , set time bar back to zero, and select [Animation]->[Start/Stop Animation] rom the main menu bar. Then the particle animation starts.
As can be seen in Figure 30, since the sub-grid scale turbulence is not included in the output velocity from the solver. It only shows very simple steady and uniform movement.
Tracer Tracking by UTT¶
From the iRIC startup screen, select [New Project], and in the solver selection screen appears. Select “UTT” and click “OK” ( Figure 31 ).
A window with [Untitled -iRIC 3.0.xxxx] [UTT] appears, and the UTT session is started. (Figure 32 )
Right click [Grid(No Data)] and select [Import] as (Figure 33 ).
As shown in Figure 34, select [Case1.cgn] which contains the grid data used in the previous section of [Computational Results of NAys2DH], and click [Open].
Single Tracer Tracking(Without Turbulent Diffusivity)¶
Choose [Calculation Condition]->[Setting] as Figure 37
As shown in Figure 38 set filename at [Basic Settings]-> [Flow information file name] as the CGNS file to read the calculation result of the flow field. Here, the CGNS file produced by the Nays2DH computation. ( Flow calculation run by Nays2DH ).
The rest of the [Basic Settings] are set as Figure 39 . Note that the tracers used are only [Normal Tracers]. The tracers used here are [Normal Tracers] only, but no [Special Tracers] are used.
Set [Diffusion Condition]->[Diffusivity Correction]->[No], and click [Save and CLose]
When the computation finishes, Figure 44 appears, and click [OK] for confirmation.
Visualization of Computational Results¶
From the main menu, select [Calculation Result]->[Open ne 2D Post-processing Window], then [2D Post Processing Window] appears as Figure 45.
It is obviously very simple because it doesn’t including any turbulent effect (Figure 47).
Single Tracer Tracking(With Turbulent Diffusivity)¶
Setting Computational Condition¶
Change the calculation conditions to take into account for the effect of turbulent diffusion. From the main menu, select [Calculation Conditions] → [Setting], and show the Figure 48. Set [Diffusion Condition]->[Diffusivity Correction]->[Yes], set the parameter [A Value] to , and then click “Save and Close”.