Computational Fluid Dynamics I - UDCcaminos.udc.es/info/asignaturas/201/CFDI_SMS_2.pdf · • SMS (Surface-Water ... – ADCIRC, CGWAVE, fo r coastal analysis ... Computational Fluid

Universidad de A CoruñaEscuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos

Computational Fluid Dynamics IPablo Rodríguez-Vellando Fernández-Carvajal

CFD IComputational Fluid Dynamics I

Hochschule Magdeburg-StendalFachbereich Wasser und Kreislaufwirtschaft

SMS

Index

0. Introduction to SMS

1. Creating a mesh introducing data trough the screen (Mesh mod)

2. Creating a mesh from a .dxf, .shp, .jpeg (Map mod)

3. Giving heights to a mesh (Scatter mod)

4. Boundary conditions, characterizing the mesh

5. Execute RMA2

6. Rendering the results

7. Unsteady flow

8. Execute RMA4

9. Tutorial 1. St Mary meander

10. Tutorial 2. Meirama Lake


• SMS (Surface-Water Modeling System) is a hydrodynamical calculus environment developed by• Brigham University

• U.S. Army Corps of Engineers

• Federal Highway Administration

• Including modules for

– Pre-process, for creating meshes for finite elements and finite volumes

– Post-process, for exporting, visualizing and rendering results

– Calculus, among which

• US Army Corps of Engineers

– TABS

» GFGEN, geometrical processing of the mesh

» RMA2, 2D model for sub-critic hydrodynamical calculus

» RMA4, water quality and transport of reactants

» RMA10, quasi-3D stratified flow for sub-critic hydrodynamical calculus

» SED2D-WES, for sediment transport

– ADCIRC, CGWAVE, for coastal analysis

– HIVEL2D, for super-critic flow

– HEC-RAS, one-dimensional calculus of channels

• FHA and others (FESWMS-FLO2DH, M2D, GHOST,…)


• There are other ‘families’ of hydrodynamical software such as Mike (Danish Hydraulic

Institute), Delft (Delft Hydraulics) or Fluent (Ansys),…

• We are going to focus on the 2D FEM hydrodynamical analysis and will be using mainly

RMA2 and RMA4

• The final aim will be obtaining the hydrodynamic fields for steady and unsteady

conditions, and further results also, such as the pollutants concentration or saline

intrusions. These data could be also used as inputs for other software codes.

• Teaching this friendly user tool within CFD I, completes aspects of hydraulics and

Computational Fluid Dynamics I, on theoretical aspects of hydrodynamical finite element

models which have been taught previously

• Also in the family• GMS Groundwater Modeling System

• WMS Watershed Modeling System


• RMA2 is a part of TABS (developed by the U.S. Army Corps of Engineers) that also includes

GFGEN, RMA4, RMA10 and SED2D-WES among others codes

• RMA2 models the sub-critic flow ( ) and includes tools for the wet-dry condition and porosity

trough marshy wet lands

• RMA2 is a FE model that solves the Shallow Water Equations taking an constant eddy viscosity and

assessing in that way the turbulent energy losses through a zero-equations turbulent model

• RMA4 is a FE model that, taking the hydrodynamics variables obtained at RMA2 as an input, gives the

concentration of a pollutant at the domain for unsteady conditions

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• SMS is based upon the following modules

– The Mesh Module, for generating and managing 2D element meshes, to be used in connection with

RMA2, RMA4, SED-2D, HIVEL2D, ADCIRC, CGWAVE, FESWMS,…

– The Extruded mesh Module, with boundary adjusted cells, to be used in finite differences and in

connection with CH3D and ICM for hydrodynamical calculus

– The 2D and 3D Cartesian Grid Module, to be used in connection with finite differences modules with

cells parallel to the axis (STWAVE, GHOST y M2D, coastal and wave models)

– The Scatter Module, manages groups of scatter points for interpolating their characteristics (height) for

a given mesh

– The Map Module, for managing the earth information, takes into account four different types of objects:

• Features, to provide GIS characteristics (points (points, nodes or vertices), arcs and polygons, ordered in layers)

• Images, from maps, aerial views,… as TIFF, JPEG,…

• Drawings, providing additional information: text, lines, polygons,…

• DXF, AutoCad or Microstation files

– The 1-D Module, to be used in connection with HEC-RAS


• The access is done through

– Usuario: masteragua

– Contraseña: M4st3r4gu4

– Conectarse: AI

• The SMS screen is made up of

Menu bar

Edit window

Tool palette

Project Explorer

Graphic screen

Mode bar Status Bar


• The main modules we will be using are

Mesh module

Scatter module

Map module

• The Project Explorer Window allows to view all the data that makes up the project, is

used for switching modules, select coverages or data sets and set display settings

• Before starting we should stick to the International System for all measures by doing

Edit/ Current Coordinates


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4





In Mesh mode

We can create, edit and modify nodes

We can create, edit and modify ‘nodestrings’ connecting nodes

A 2D region is obtained


• Once we´ve got nodes and nodestrings we can distribute more nodes

– At the nodestrings editor we select all, and open the menuElements/Rectangular Patch

– In this dialog window we can distribute nodes and adjust the ‘bias’ to generate a quadrangular mesh

– Once created, we can select them with the elements editor


• At Elements/Merge Triangles we can join triangles into quadrilaterals

• At Elements/Split Quadrilaterals, quadrilaterals can be split apart

• At Elements/Linear<->Quadratic we can change the interpolation order of the elements


Display options for shade, contours, vectors, information and plots


Pan, Zoom y Rotate, for displacing, zooming or rotating the view in 3D

Refresh, Frame, Display options and Plane view for applying changes,

adjusting the view to the mesh, show the whole of the display options or return to

the plan view

At Display/View, Plan, Front and Side views can be selected


• For avoiding duplicate nodes

Nodes/Delete Duplicate Nodes

• For renumbering nodes

– Select a nodestring and then Nodestring/Renumber

– A nodestring can be also defined clicking at the node and selecting CONTROL

– Band width modifications can be checked at info

• Save at File/Save Project


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




• A feature point defines a position which is not in an arc to

force the creation of a node at that place. A feature node is

the same but on an arc, if they are not at the borders, they

are called feature vertices

• A feature arc is a sequence of segments which are grouped

together as a polyline, they can form polygons (with a given

area) or act as the borders of a river

• A feature polygon is defined inside one or more feature

arcs

point

arc

polygons

node vertex

At the maps module a mesh can be created from a .dxf, .shp or

directly trough a scanned map as .tif, .jpg, etc…

The elements to be managed are the feature objects (Arcs,

Nodes, Vertices and Polygons)


• At the Map Module the following icons are used to create and edit arcs,

nodes, vertices and polygons (feature objects), that can be managed in layers

• First of all we should do right click at the active coverage, to turn it into a 2D

mesh with Type/Models/TABS

Select node

Create node

Select vertex

Create vertex

Edit arc

Create arc (double click closes it)

Select arc group

Select a polygon (previously created from a close arc with

Feature Objects/Build Polygons)


• Polygons can be seen by switching on the Polygon fill option at the display icon

• Double clicking at the Polygon, we can adjust the number of vertices, materials,

the bias,…

• At Adaptative tesselation it splits the domain into triangles

• At Patch makes quadrilaterals (it requires 4 sides),…


• In Feature Objects/Map->2D Mesh creates the mesh and adds constant

heights if not specified


If saved, several files will be created:

*.sms Main file with the whole project

and several additional files that can come handy for pre and post process such as

*.bc Boundary conditions

*.geo Conectivities, geometry of nodes, materials

*_gf.run Executable gfgen

*_rm.run Executable RMA2

*.materials Materials

*.sim Simulations

*.map Map features


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4





• Scatter points can be created at the mesh module from a plain point by just

providing a certain height doing

Data/Mesh->Scatterpoint

they are therefore turned into a scatter stencil and can be saved at the scatter

module as a Scatter file (*.h5), that can co-exist with the rest of the files in the

project

• Scatter points can also be created directly at the at the scatter module. Once the

scatter file is done we can give heights to a mesh by doing

Scatter/Interpolate to mesh

and the heights of each of the points at the mesh are interpolated through the

scatter information


• Do not forget to tick the Map elevation at the dialog box

• From now on the mesh points have a certain height that can be mapped as a

contour map with several rendering options

Display Options/2D Mesh/Contours


• If we are going to interpolate heights from a surveying *.dxf, we should activate the

bathymetry layers at the Project Explorer. The points can be turned into Scatter Points with

DXF->DXF Scatter point. Now we can do Scatter/Interpolate to mesh at the Scatter Module

• We can also import a surveying scatter type file and generate a mesh from it following the

isolines. At Data/Scatter Countour to Feature a contour line can be created at a certain

height that will be treated as a Feature arc to be used at the map module


• Once the feature arcs have been generated they can be turned into polygons and

the mesh can be generated in the same way as before. Do not forget to do

Type/Models/TABS clicking at the active coverage with the right hand button.

• Feature Objects/Build Polygons

• Feature Objects/Map to 2D mesh (do it twice if required)

• Heights can be given at Scatter/Interpolate to mesh (Map Z, on)


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4





• Once the mesh has been defined, boundary conditions can be assigned by

selecting the nodestring and doing RMA2/Assign boundary conditions

• Flowrate at the entrance (perpendicular to the boundary, 10m3/s) and depth at the

outlet (2m)


• Apart from flowrate and direction, an uneven distribution of the flow at the cross

section can be also specified

+ -+ +

• Boundary conditions are then loaded at the *.bc file


• At RMA2/Material Properties the

flow can be characterized by

choosing the eddy viscosity (E) and

the Manning coefficient (n)

• E will be taken as 1000 and n as

0.025 as default values

• At the SMS handbook the following

table is provided! Type of Problem E, lb-sec/ft2 E, Pascal-secHomogenous horizontal flow around an island 10-100 500-5000

Homogenous horizontal flow at a confluence 25-100 1100-5000

Steady-state flow for thermal discharge to a slow moving river 20-1000 1000-50000

Tidal flow in a marshy estuary 50-200 2500-10000

Slow flow through a shallow pond 0.2-1.0 10-50


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




• Once the geometry, the boundary conditions, and the materials properties have

been introduced, a check can be done with

RMA2/Model Check

• Some of the most usual errors are the following

– The mesh has not been renumbered -> (Select Nodestrings/ Renumber)

– The elements are not quadratic ->(Elements/Linear<->Quadratic)

– The water depth specified is not big enough

– Provide WSE (at Model Control/Optional Bc control/ Initial WSE (given depth))


• For calculating the hydrodynamics we do RMA2/Run GFEN and this…

– Generates a binary file, *.bin with geometry to be able to run RMA2

– All the possible problems are listed at *.ot1

– The b.c. do not affect the generation of this

• Once the geometry has been ‘run’, we can do RMA2/Run RMA2

– Problems are listed at *.ot2

– The result file is written *.sol


• At RMA2/Model control the FE

code parameters can be changed

• At Files we can control

– Hotstart input file to introduce

initial data to be taken as initial

conditions

– Hotstart output file to obtain an

intermediate results outcome

• At Timing we can control the

unsteady output

• At Materials you can set a dry/wet

condition specify default manning,….


• Steady or Dynamic (unsteady) conditions can be chosen at RMA2/Model Control/Timing

• At Steady state depth convergence, the accepted error to achieve convergence

is set (for example 0.0001)

• At Iterations/Initial solutions the number of iterations for the only time step is set

(steady flow). When unsteady flow is chosen the computation time box is

activated


• Now we save and run with RMA2/Run RMA2 and hope for the best

• The GFGEN module is firstly run for compiling the geometry and if everything

goes fine we can go for Run RMA2 at the lower right corner of the window


• We have now all the information at the Project Explorer.

• At the Display Options Icon we can now choose if we want to display the vector

field or the contour field and we can specify the rendering options


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




• At Display/2D Mesh/Contours we can choose

– Contour method (colour fill, normal linear,…)

– En Contour range and Contour intervals we can specify the range of colours for

the iso-lines

– We can tick/untick Legend for displaying the legend or not

– ….


• At the node editor el we can select a particular node and obtain information about the

velocity and depth at a certain point


• At the Display options/2D Mesh/Vectors we can adjust the parameters at the vector field

• At Color Range we can assign different colours to different velocity magnitudes,…

• If we change the boundary conditions, save and run RMA2 we will get a second solution

that can co-exist with the former at the Project Explorer


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




• To obtain results from an unsteady

problem we should choose

Timing/Dynamic at the RMA2 Model

Control Dialog box

• At Iterations we can choose the

number of iterations and converge

parameters for depth at each time step

• At Computational Time we can

choose the number of steps and the

time for each one


• For obtaining results varying in time we should modify the boundary conditions at

RMA2/ Assign BC

• Once there, we can choose Transient and define the curve

• We could import there a file from an excel file (for example) or introduce new data with New


• Once RMA2 has been run a window appears at the left bottom corner showing

the results for each of the time steps

• The SMS post- processor also allows for a creating movies with Data/ Film Loop


• There we can prepare animations for scalar and vectorial fields and also flow trace movies



Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




• The RMA4 model is used for tracking a constituent concentration in 2D models,

through the resolution of the transport equation

• It should take the hydrodynamic results from a previous run of RMA2 as an input

• It should be used with metric units


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• First we should obtain the hydrodynamic fields for a certain domain

• Lets create a winding channel in metric units (Edit/Current Coordinates)

• At the Map module create some Feature Arcs (do not forget to right buttom

Type/Models/TABS at the coverage) and build a mesh (Feature Objects/Build Polygons)

• Feature Objects/Attributes, refine a bit and the create with Feature Objects/Maps >> 2D Mesh


• RMA2/Model Contol/Timing: Time step 0.1, number of time steps 240, maximum time 24h

• We will know create Nodestrings at the inlet and the outlet and introduce boundary conditions at

RMA2/Assigning boundary conditions (10m3/s at the inlet and from 5 to 2 m at the outlet twice

along the day)

• Default Eddy viscosity and Mannings will be kept

• Nodestrings Renumber, Save project, Run RMA2 (Sometimes it could show an error at GFGEN

which is not real, try to run first for steady state conditions)


• We will now introduce a concentration of a certain pollutant at the inlet on the steady solut.

• At RMA4/Model Control, the Start time will be set to 0, the Time step 0,1 hours, the Total steps to 240 and the max time to 24 (if smaller than time steps plus total steps, the solution will

be truncated)

• At files, choose *.sol and tick Write RMA4 Solutions File and Activate full report

• Last time step set to 24.0 and time subtracted 0


• RMA4/Assign boundary conditions/Constant, and introduce a constant concentration of

999ppm (the units of the solution will those of the input)


• At RMA4/Material Properties choose a diffusion coefficient of 10m2/s

• Save! All the affected files should be at the same directory!

• RMA4/Run RMA4

• Open RMA4 results with File/Open/*.qsl

• At Data/Film loop an animation can be done (for an hour, for example)


• Observation sections can be defined by right clicking at the project explorer Map Data/New Coverage/Observation

• At this coverage we can define a couple of arcs as cross sections

• Once done we can go to Display/Plot Wizard/Observation profile and plot the present data

• At Display/Plot Display options we can costumize, export the plot, etc


• Observation points can be also defined at the same coverage to plot variations in time of the flow

variables at that point

• Once created we can go to Display/Plot Wizard/Time series and plot the present data

• At Display/Plot Display options we can costumize, export the plot, etc


• We can compare computed values with real ones if we have them for depth, velocity,…

• If we double click on the observation arc or point or do Feature Objects/Attributtes, and

then we do Module/2D mesh, velocity mag (for example), we can introduce measured data

through the keyboard or also import data from a file, for arcs and points, at both steady and

unsteady (trans) conditions


• Once done we can go to Mesh Module/Display/Plot Wizard/Computed versus observed data and plot the present data


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




Tutorial 1.Obtaining the flow at a meander from a scanned picture. The St Mary meander


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




• We are going to open an scanned .jpg image first

File/Open/c:/Program files/SMS10.0/Tutorials/General/Overview/data files/stmary.jpg

A

B


• This file is already georeferenced. When not, the

Resister Image dialog appears and relative and

absolute coordinates should be matched for three

points (1,2 and 3)

• Feature objects can be converted from an existing

.dxf or .dwg file or from the survey data

• Feature objects can also be digitalized inside SMS by

doing

• To create a feature arc, the icon is selected and the arc is adjusted to the topographic line of the boundary

– The last vertex can be removed with the ‘backspace’

– ESC will erase the whole arc. Double click to finish the arc

– At Feature Objects/Redistribute vertices, the number of vertices of an arc can be changed

– A new coverage could be imported to co-exist with the one we have just done by doing

File/Open/c:/Program files/SMS10.0/Tutorials/General/Overview/data files/stmary1.map

– Several coverages can co-exist at the same project and can be activated, deactivated, erased, renamed, etc.

– En Feature Objects/Vertices <->Nodes, nodes are swapped by vertices and vice-versa and therefore arcs

connect or split apart

– Vertices can also be created, moved and erased

– At Feature Objects/Transform, feature object

can be provided with a height


• Materials should be assigned by first creating them with

Edit/Materials data

• The types can be later defined at RMA2/Material properties

• To see the material we can go to Display/Maps/Polygon fill/Materials


• Polygons are going to be built inside closed arc

groups

• To define polygons we should first do right click on

the coverage, which should be turned into a 2D

mesh with Type/Models/TABS

• Once all the arcs have been generated we can build

the polygons with

Feature Objects/ Build Polygons

• Selecting the polygon with a double click (or in Feature Objects/Attributes) the mesh can be

characterized and modified by adding or removing

vertices, changing the triangulation method…


• Once the information about the ground has been introduced, and the mesh defined, it

should be created with Feature objects/Map to 2D mesh

• At the Mesh Mode check for duplicate nodes at Nodes/Delete duplicate nodes and

renumber at Nodestring/Renumber from a Nodestring


• Now we should add bathymetrymetric data. Open the file with the survey information

File/Open/c:/Program files/SMS10.0/Tutorials/General/Overview/data files/stmary_bathy.h5

• At the scatter mode select Scatter/Interpolate to mesh

• Select Map Z at the box. Now the z-coordinate has been incorporated to the mesh


• Now we can see the bathymetric contour field by clicking at the project


• Now for running the model we should introduce eddy viscosities and Manning coeficients

for every material we had previously defined

E(lb-sec/ft2) n(sec·ft -1/3)Left_Channel 50 0.04Main_Channel 50 0.03Right_Channel 50 0.04


• As boundary conditions we can set 40000 ft3/s (some 1500m3/s) at the inlet and

a 20ft water height (some 6m) at the outlet

• Afterwards

RMA2/Model Check

File Save Project

RMA2/Run RMA2

• If GFGEN doesn´t work renumber the mesh and try again

• At the project explorer we´ve got now the solution as a vector and a contour field




Tutorial 2. Meirama LakeObtaining the flow from GIS files *.shp, *.dxf, *.txt,…


Index






5. Execute RMA2


7. Unsteady flow

8. Execute RMA4




• We should now switch to international coordinates at Edit/Current Coordinates

• In order to introduce real data for hydrodynamic characterization of flows it is very useful to

consider compatibility with other GIS and CAD programs, such as ArcGIS, AutoCAD etc… SMS

can read data from *.dxf, *.shp, *.txt file, etc… If we start with a file containing surveying data

(SIGPAC) we can also proceed as follows File/Open/Barcés.txt/Open file as XYZFiles(*.xyz)

• It takes the data as a scatter file and we can save it as a *.h5 and a *.sms file


• Let´s do now at the Scatter module Data/Scatter Contour to feature, at heights 180, 150

and 80 m, with a spacing of 30m


• Lets close the ‘dam’ at height 180 m at the Maps Module and erase the non-required arcs

• Lets hide the scatter points


• Following, materials can be defined in the Mesh Module at Edit/Materials Data, where three

new materials are created


• Right button click at the coverage, then Type/model/TABS

• Feature Objects/Build Polygons

• Select Polygons, then double click at polygon and define the mesh with a smaller

refinement

• Assign the three materials and show them with the display options


• Once we are done, Feature Objects/Map->2D Mesh

• Do it twice, if necessary


• Heights can be provided with Scatter/Interpolate to mesh (Do not forget to tick Map Z)

• Now heights can be seen as a contour map through the display options


• Following, materials can be defined in the Mesh Module at RMA2/Material Properties

• We are going to generate three different types of materials with Mannings, n=0.03, 0.025 y

0.02 (s·m-1/3) (given as default as 0.025) and Eddy Viscosity, E=2000 Pascals·s

• The RMA2 is very sensible to E. It should be adjusted with care and calibrated when possible.

The values proposed by the handbook are the following


Type of Problem E, lb-sec/ft2 E, Pascal-secHomogenous horizontal flow around an island 10-100 500-5000

Homogenous horizontal flow at a confluence 25-100 1100-5000

Steady-state flow for thermal discharge to a slow moving river 20-1000 1000-50000

Tidal flow in a marshy estuary 50-200 2500-10000

Slow flow through a shallow pond 0.2-1.0 10-50

• Before running RMA2 we should renumber the mesh selecting a nodestring and doing

Nodestrings/Renumber

• Introduce b.c.: 181m at the dam spillway (change height of the spillway to 180m). An

inflow at the NW nodestring of some 100 m3/s and spot inflow velocity of (1,1) m/s at 45º at

a certain SW point by doing (RMA2/Assign BC/Velocity components)


• The model can be now run with

– RMA2/Model Check/Run check

– Run RMA2

– Run RMA2



Documents

Computational Fluid Dynamics I - UDCcaminos.udc.es/info/asignaturas/201/CFDI_SMS_2.pdf · • SMS (Surface-Water ... – ADCIRC, CGWAVE, fo r coastal analysis ... Computational Fluid