SWASH USER MANUAL SWASH version 7.01 SWASH USER MANUAL by : TheSWASHteam mail address : Delft University of Technology Faculty of Civil Engineering and Geosciences Environmental Fluid Mechanics Section P.O. Box 5048 2600 GA Delft The Netherlands website : http://www.tudelft.nl/swash Copyright (c) 2010-2020 Delft University of Technology. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back- Cover Texts. A copy of the license is available at http://www.gnu.org/licenses/fdl.html#TOC1. iv Contents 1 About this manual 1 2 Generaldescriptionandinstructionsforuse 3 2.1 Introduction................................... 3 2.2 Background,featuresandapplications . ...... 3 2.2.1 Objectiveandcontext ......................... 3 2.2.2 Abird’s-eyeviewofSWASH. 4 2.2.3 ModelfeaturesandvalidityofSWASH . 7 2.2.4 Relation to Boussinesq-type wave models . .... 8 2.2.5 Relation to circulation and coastal flow models. ...... 9 2.3 Internal scenarios, shortcomings and coding bugs . ......... 9 2.4 Unitsandcoordinatesystems . 10 2.5 Choiceofgridsandtimewindows . .. 11 2.5.1 Introduction............................... 11 2.5.2 Computationalgridandtimewindow . 12 2.5.3 Inputgrid(s)andtimewindow(s) . 13 2.5.4 Input grid(s) for transport of constituents . ...... 14 2.5.5 Outputgrids .............................. 15 2.6 Boundaryconditions .............................. 16 2.7 Timeanddatenotation ............................ 17 2.8 Troubleshooting................................. 17 3 Input and output files 19 3.1 General ..................................... 19 3.2 Input/outputfacilities . .. 19 3.3 Printfileanderrormessages . .. 20 4 Description of commands 21 4.1 Listofavailablecommands. .. 21 4.2 Sequenceofcommands ............................. 23 4.3 Command syntax and input / output limitations. ...... 24 4.4 Start-up ..................................... 24 PROJECT................................ 24 v vi SET ................................... 25 MODE.................................. 27 COORDINATES ............................ 27 4.5 Modeldescription................................ 28 4.5.1 Computationalgrid........................... 28 CGRID ................................. 28 READGRIDCOORDINATES. 30 READGRID UNSTRUCTURED . 31 VERTICAL............................... 31 4.5.2 Inputgridsanddata .......................... 32 INPGRID................................ 32 READINP................................ 37 INPTRANS............................... 42 READTRANS ............................. 43 4.5.3 Initialandboundaryconditions . .. 43 INITIAL................................. 43 BOUND SHAPE . 44 BOUNDCOND ............................. 45 SOURCE ................................ 52 SPONGELAYER ........................... 53 FLOAT ................................. 54 4.5.4 Physics.................................. 55 WIND.................................. 55 FRICTION ............................... 58 VISCOSITY............................... 60 POROSITY............................... 62 VEGETATION ............................. 63 TRANSPORT.............................. 64 BREAKING............................... 68 4.5.5 Numerics ................................ 69 NONHYDROSTATIC ......................... 69 DISCRETIZATION .......................... 74 BOTCEL ................................ 77 TIMEINTEGRATION......................... 78 4.6 Output...................................... 80 4.6.1 Outputlocations ............................ 81 FRAME................................. 81 GROUP................................. 82 CURVE ................................. 83 RAY................................... 83 ISOLINE ................................ 84 POINTS................................. 84 4.6.2 Writeorplotcomputedquantities. .. 85 vii QUANTITY............................... 85 OUTPUT ................................ 88 BLOCK ................................. 88 TABLE ................................. 98 4.6.3 Writeorplotintermediateresults . ... 99 TEST .................................. 99 4.7 Lock-up ..................................... 101 COMPUTE ............................... 101 STOP .................................. 101 5 Setting up your own command file 103 5.1 Computationalgrid............................... 103 5.2 Inputgrids.................................... 107 5.3 Initialandboundaryconditions . .... 109 5.4 Numericalparameters ............................. 112 5.4.1 Durationofsimulation . 112 5.4.2 Timestep ................................ 113 5.4.3 Verticalpressuregradient . 113 5.4.4 Momentumconservation . 114 5.4.5 Discretization of advection terms in the momentum equations . 115 5.4.6 Movingshorelines............................ 117 5.5 Physicalparameters. 117 5.5.1 Depth-inducedwavebreaking . 117 5.5.2 Subgridturbulentmixing. 119 5.5.3 Verticalturbulentmixing. 119 5.5.4 Bottomfriction ............................. 119 5.6 Output quantities, locations and formats . ....... 119 5.7 Theimportanceofparallelcomputing. ..... 120 A Definitions of variables 123 B Command syntax 127 B.1 Commandsandcommandschemes . 127 B.2 Command .................................... 127 B.2.1 Keywords ................................ 127 Spellingofkeywords . 128 Requiredandoptionalkeywords . 128 Repetitionsofkeywordsand/orotherdata . 129 B.2.2 Data................................... 129 Characterdataandnumericaldata . 129 Spellingofdata ............................. 129 Requireddataandoptionaldata . 131 B.3 Commandfileandcomments. 131 viii B.4 Endoflineorcontinuation. 132 C File swash.edt 133 Bibliography 141 Index 142 Chapter 1 About this manual The information about the SWASH package is distributed over two different documents. This User Manual describes the complete input and usage of the SWASH package. The Implementation Manual explains the installation procedure of SWASH on a single- or multi- processor machine with distributed memory. Apart from these documents, programmers who want to further develop SWASH can also consult the Programming rules as applied for SWAN; see http://www.swan.tudelft.nl for further details. In Chapter 2 general description of the model and some instructions concerning the usage of SWASH, the treatment of grids, boundary conditions, etc. are given. It is advised to read this chapter before consulting the rest of the manual. Chapter 3 gives some remarks concerning the input and output files of SWASH. Chapter 4 describes the complete set of commands of the program SWASH. In Chapter 5 some guidelines for setting up a command file is outlined. It is strongly advised that users who are not so experienced in the use of SWASH should first read Chapters 2 and 3. Also, Chapter 5 is recommended. This manual also contains some appendices. In Appendix A definitions of some parameters are given. Appendix B outlines the syntax of the command file (or input file). A complete set of all the commands use in SWASH can be found in Appendix C. 1 2 Chapter 1 Chapter 2 General description and instructions for use 2.1 Introduction The purpose of this chapter is to provide the user with relevant background information on SWASH and to give some general advice in choosing the basic input for SWASH com- putations. A general suggestion is: start simple. SWASH helps in this with default options. Moreover, it is a good idea to read Chapter 5 first when setting up a command file for the first time. Furthermore, suggestions are given that should help the user to choose among the many options conditions and in which mode to run SWASH (1D or flume-like, 2D or basin-like, depth-averaged or multi-layered, etc.). In addition, the way you need to specify the para- meters and options resembles to that of SWAN. Hence, those users who are familiar with SWAN should be able to use SWASH without much effort. It is recommended to carry out some available test cases first to get acquaint with the program. 2.2 Background, features and applications 2.2.1 Objective and context SWASH is a general-purpose numerical tool for simulating non-hydrostatic, free-surface, rotational flows and transport phenomena in one, two or three dimensions. The governing equations are the nonlinear shallow water equations including non-hydrostatic pressure and some transport equations, and provide a general basis for simulating wave transformation in both surf and swash zones due to nonlinear wave-wave inter- • actions, interaction of waves with currents, interaction of waves with structures, wave damping due to vegetation, and wave breaking as well as runup at the shoreline, 3 4 Chapter 2 complex changes to rapidly varied flows typically found in coastal flooding resulting • from e.g. dike breaks, tsunamis, and flood waves, density driven flows in coastal seas, estuaries, lakes, and rivers, and • large-scale ocean circulation, tides and storm surges. • The model is referred to as a wave-flow model and is essentially applicable in the coastal regions up to the shore. This has prompted the acronym SWASH for the associated code, standing for Simulating WAves till SHore. The basic philosophy of the SWASH code is to provide an efficient and robust model that allows a wide range of time and space scales of surface waves and shallow water flows in complex environments to be applied. As a result, SWASH allows for the entire modelling process to be carried out in any area of interest. This includes small-scale