[Example 4] Flow in a real river(single cross section)
Select Solver
In the [Select Solver] window, Figure 84 , select [Nays2d+] and click [OK].
Importing River Survey Data
In the window, Figure 85, select [Import], [Geographic Data], [Elevation(m)]
Chose [single.riv] in the window, Figure 86 and open. The cross sectional survey data “single.riv” can be downloaded from, https://i-ric.org/yasu/fw/rivfiles/single.riv
A message window may appear telling “Problems Fund i Data” as Figure 87 ,but just click [OK]
Select [Middle point of left and right bank] in the [River Survey Data Import Setting] window as Figure 88 , and click [OK]
Figure 89 riv file import complete.
Grid Generation Conditions
From the main menu, select [Grid] and [Select Algorithm to Create Grid] as, Figure 90
Select [Create grid from river survey data] from the window, Figure 91 , and click [OK].
As shown in Figure 92 , a channel with cross sections with both ends’ blue circles are displayed.
Grid Generation
Select any side of one of the cross section line, right click, and chose [Add Division Points].
Set [Division Number], set [4] in this example, and click [OK] (Figure 94 )
Select one of the opposite side of the cross sectional line we selected in Figure 93 , right click, and chose [Add Division Points] (Figure 95 )
Set [Division Number], set [4] as a same number we set in Figure 94 for the symmetry.
Along the channel direction, division points are set all at once. Select [Grid], [Add Division Points Regionally] from the menu bar. ( Figure 97 )
Chose [Specify target distance division points]. set distance [70] in this example, and click [OK].( Figure 98 )
When the setup for division points are completed, a plane map with yellow circle points appears as Figure 99
Select [Grid], [Grid Create] from the menu bar.( Figure 100 )
Confirm the grid generation range painted with blue, and click [OK].
Answer [Yes] when you asked [Do you want to map?] as Figure 102
Completed grid is shown as Figure 103
Bed configuration and channel shape can be confirmed by putting checking marks at, [Grid], [Node attributes] and [Elevation (m)]. ( Figure 104 )
Computational Condition
Select [Calculation Condition] and [Setting] from the min menu as Figure 105 .
Set [Time unit of discharge] as [Hour] and click [Edit], ( Figure 106 )
Set discharge hydrography as Figure 107, constant for 3 hours with 2,000 qms, and click [OK].
Set [Time and bed erosion condition] as Figure 108 .
Set [Boundary Conditions] as Figure 109 .
Set [Initial Water Surface Profile] as Figure 110 .
Set [Other computational parameters] as Figure 111 .
Set “3D Velocity Profile” as shown in the figure Figure 112 , and click [OK] to exit.
Launch Computation
From the menu bar, select [Simulation] and [Run].
Answer [Yes(Y)] when you asked [Save the project?] as Figure 114
Simulation starts. Figure 115
Click [OK] when the message [The solver finished calculation] as Figure 116
Display Computational Results
After the companion finished, form the main menu, by selecting [Calculation Results] and [Open new 2D Post-Processing Window], a new Window appears as Figure 117 .
Depth
n the object browser, put the check marks in “Scalar (node)” and “Depth[m]”, right-click and select “Properties”. The “Scalar Setting” window Figure 118 appears.
Set the values as shown in Figure 118, and click [OK], then Figure 119 appears.
Display Background Image
Select from the main menu, [File]->[Property] ( Figure 120 )
From the “Project Property” window, click [Edit] at [Coordinate System] .. _04_haikei_02:
Input “Japan” in the [Search] window, and chose the one with “XII” from the items with [EPSG:….] as Figure 122 . See more detail on coordinate system of Japan at http://www.gsi.go.jp/sokuchikijun/jpc.html
Click [Close] of [Project Property] window of Figure 123
Put a check mark in a box in front of [Background Images(Internet)] and one of the items listed below, e.g., [Google Map (Sattelite Image)] as Figure 124
Velocity Vectors and Streamlines
Since the operation method is the same as the previous section, it will be omitted.
Particle Animations
Put check mark at [Particles] and [Velocity] in the object browser, put time bar back to zero, and push black button, ( Figure 125 ). Particle following the depth averaged velocity starts as Figure 126 .
Make the Particles riding the surface velocity are displayed in red. Put ☑ in “Particle” and “SurfaceVelocity”, right-click on “Particle” and select “Properties” to display “Particle setting screen” Figure 127, so set it as shown in the figure and Click [OK]. Reset the time bar to zero and press the play button to display the particle animation caused by the surface flow of Figure 128.
In the same way, the particle flowing animations can be played by checking a box at [Bottom Velocity], respectively.