## Generation of Boundary Conditions

### From BAWiki

Besides work related to the generation and modification of grids the preparation of proper boundary conditions is one of the most important but also sometimes tedious steps preparing simulation runs using mathematical models. In addition to initial-conditions, time- as well as spatially varying boundary conditions must be prescribed for all boundaries of the modelling domain during the whole simulation period. Data needed may be for example bottom roughness, wind above the water surface (see in this respect also Wind über Ästuaren), water level elevation at the ocean boundary (e.g. North Sea), fresh water flow, etc.

This page gives you a comprehensive overview about all programs actually used at BAW-DH for the purpose of generating boundary conditions for numerical model simulation runs. The following topics are covered:

## Contents

- 1 Literature about methods
- 2 Graphical Representations of Complex Workflows
- 2.1 Generation of Time Series Data from Measured or Simulated Data
- 2.2 Preparation of Meteorological Data
- 2.3 Preparation of Soil-Identification Numbers
- 2.4 Boundary Conditions for Delft3D and UNTRIM
- 2.5 Boundary Conditions for TELEMAC-2D
- 2.6 Boundary Conditions for TRIM-2D
- 2.7 Boundary Conditions for TRIM-3D

- 3 Model-Independent Preprocessors
- 4 Model-Dependent Preprocessors

## Literature about methods

- Seiß, G.: Erzeugung naturähnlicher Randwerte für den seeseitigen Rand von Ästuarmodellen an der Nordsee. Technical document, in German, 2014.

## Graphical Representations of Complex Workflows

### Generation of Time Series Data from Measured or Simulated Data

Graphical representation of workflow during the generation of boundary time series data from measured or simulated results (available in German only). This graphical representation is also available in Encapsulated PostScript format.

### Preparation of Meteorological Data

Graphical representation of the workflow for preparing meteorological data for later usage as boundary conditions (with German text only). This graphical representation is also available in Encapsulated PostScript format.

### Preparation of Soil-Identification Numbers

Under Construction

### Boundary Conditions for Delft3D and UNTRIM

Graphical representation of the workflow for generating boundary conditions for the mathematical models DELFT3D. and UNTRIM. This graphical representation is also available in Encapsulated PostScript format.

### Boundary Conditions for TELEMAC-2D

Graphical representation of the workflow for generating boundary conditions for the mathematical model TELEMAC-2D This graphical representation is also available in Encapsulated PostScript format.

### Boundary Conditions for TRIM-2D

Graphical representationof the workflow for generating boundary conditions for the mathematical model TRIM-2D (with German text only). This graphical representation is also available in Encapsulated PostScript format.

### Boundary Conditions for TRIM-3D

At the moment boundary conditions for the mathematical model TRIM-3D may be generated in the same way as for TRIM-2D. Only depth-independent boundary conditions can be prescribed actually.

## Model-Independent Preprocessors

### Modification and Display of Digitized Data

- DIDGER: The standard software DIDGER, developed by Golden Software, enables the user to digitize scanned time series. The further processing of the DIDGER output takes place in Mathematica. For further information contact M. Kastens.
- ZEITRIO: Splitting continuous digitized time-series (several days or weeks long) into daily portions. This step is optional. If you don't want to print the data in the original format of the gauge recording sheets, you can leave out ZEITRIO
- MESKOR: Making corrections (addition or subtraction of a constant, removal of a linear trend) to the digitized data.
- GVIEW2D: Display of corrected digitized time-series data for the whole period of digitization. Overlaying several curves (e.g. for different locations) renders insight into inconsistencies not seen in single curves (e.g. incorrect time-shift or wrong mean water levels).

### Generation of Time Series Data from Measured or Simulated Data

- UTRRND: Extraction of boundary time series data from numerically simulated results, which are available either for the overall computational domain, along selected profiles or at individual locations. Measured data can also be used as an option. Required workflow is shown under Boundary Conditions for UNTRIM (see above).

### Pack various Time-Series Data together

- FRQ2ZEITR: Evaluation of water level elevation from tidal harmonic constituents and corrections given in tables published by Federal Maritime and Hydrographic Agency of Germany (BSH) taking into account correct values for amplitude and phase.
- TSCALC: This program allows a few mathematical operations on time-series data. Two time series can be added, subtracted, multiplied or divided in a large number of different ways.
- UTRRND: The UTRRND user is able to prepare different time-series for later use in mathematical models, (see above Generation of Time Series Data from Measured or Simulated Data). Besides the direct generation of boundary data for UNTRIM it can be used before specific preprocessors for other hydronumerical models.

### Preparing Meteorological Boundary Data

- BSH2BAW: This program converts meteorological data into the mkwswawrt.dat format. This format can be later read by the program FD2MET. The data were made available for BAW-DH by the Federal Maritime and Hydrographic Agency of Germany (BSH).
- FD2MET: Meteorological quantities which are usually varying in space and time can be generated either from basic meteorological data sets measured at various locations (e.g. wind speed, wind direction, air pressure) or from numerically calculated windfields. The latter ones are given to BAW-DH through Wetterdienst (Geschäftsfeld Seeschiffahrt).
- METDIDA: Meteorological data produced with FD2MET can be transformed using the program METDIDA in such a way, that they can be visualized and verified using HVIEW2D (see also Supercompting News No. 1/1998).

### Preparation of Soil-Identification Numbers

- MKRDAT: With this program spatially varying soil-identification numbers can be mapped onto grids for numerical models. Normally several physical quantities are related to one identification numbers to describe physical properties of the ground (e.g. roughness, conductivity, etc.).
- Initial values file for physical datasets ipds.dat: DELFT3D as well as the morphodynamic model SEDIMORPH import initial values for soil-identification numbers stored in ipds.dat. At BAW SEDIMORPH is coupled with the numerical models TELEMAC-2D and UNTRIM.

The file content can be explored by means of the visualisation tool Davit.

## Model-Dependent Preprocessors

### Preparing Boundary Conditions for DELFT3D

- UTRRND: This preprocessor is used for conversion of boundary information into a special storage format BDF data format.
- OpenMI: The reading of these files is done OpenMI compliant. In a first step the GEIWRAPPER reads the boundary data. The further DELFT3D import takes place in the OpenMI environment at run-time.

### Preparing Boundary Conditions for TELEMAC-2D

- TICTRI: This program converts a finite element grid as well as information about the type of boundary conditions applied into TRIGRID-format. Converted data-sets will be used later together with special preprocessing software.
- TM2RND: The program TM2RND converts various given time-series for boundary conditions into a special data format which can be used in a TELEMAC-2D simulation run.

### Preparing Boundary Conditions for TRIM-2D

- FDGITTER05: This program can be especially used to define and/or modify boundary grid cells. At the end of program execution boundary cell information may be optionally saved to a file of type rgz.dat. Stored information may be retrieved at later stages of the processing chain.
- TR2RND: This preprocessor is used for conversion of boundary information into a special storage format which enables fast access for the progam TRIM-2D during simulation.

### Preparing Boundary Conditions for TRIM-3D

Boundary conditions for TRIM-3D must be actually generated in the same way as for TRIM-2D.

### Preparing Boundary Conditions for UNTRIM

- UTRRND: This preprocessor is used for conversion of boundary information into a special storage format BDF data format, which can be easily read by the progam UNTRIM during simulation.

back to Pre- and Postprocessing