tdynreference manual
Tdyn
Environment for Fluid Dynamics (Navier Stokes equations), Turbulence, Heat Transfer, Advection of Species and Free surface simulation.
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Reference Manual
© COMPASS Ingenierķa y Sistemas SA
info@compassis.com
5th Revision Tdyn 3.5 March 2002
Table of Contents
About this Manual.......................................................................... 6
Introduction...................................................................................... 7
Pre-processing..................................................................................... 8
Calculate............................................................................................ 10
Post-processing.................................................................................. 10
Tdyn Reference............................................................................. 12
Conditions.......................................................................................... 12
Conditions available in module RANSOL........................................ 13
Conditions available in module HEATRANS................................... 22
Conditions available in module ADVECT........................................ 24
Conditions available in module NAVAL.......................................... 25
Materials............................................................................................ 26
Fluid Material................................................................................. 27
Solid Material................................................................................. 36
Boundaries......................................................................................... 38
Fluid Body..................................................................................... 40
Fluid Boundary............................................................................... 44
Solid Boundary............................................................................... 46
Free Surface................................................................................... 47
Problem Data..................................................................................... 51
Problem......................................................................................... 51
Solver............................................................................................ 64
Units.............................................................................................. 69
Create Report tool.................................................................... 72
Tdyn Wizard....................................................................................... 74
Preliminary step (read or create the geometry based on standard layers)76
Create control volume......................................................................... 79
Define Data........................................................................................ 82
Generate Mesh................................................................................... 85
Calculate............................................................................................ 86
Postprocessing................................................................................... 88
Making Graphs................................................................................... 91
Reporting........................................................................................... 92
Update Sink and Trim Data................................................................ 94
Function Syntax............................................................................ 98
Turbulence modelling........................................................... 107
RANS equations and turbulence models............................................ 108
Classes of turbulence models available in Tdyn.................................. 109
Algebraic (or zero-equatjon) models (Smagorinsky and Mixing Length models) 109
One-equation models (Kinetic energy or k model and Spallart-Allmaras model) 110
Two-equation models (k-ε model, k-ω model, k-ω SST model, k-kt model) 110
Final recommendations on turbulence modelling................................. 112
Near wall-modelling............................................................... 114
Law of the Wall functions.................................................................. 118
Weaknesses of the k-ε model with wall functions............................... 119
Some comments on Boundary Conditions.................. 121
General guidelines on boundary conditions......................................... 121
Specification of turbulence quantities at an inlet.................................. 123
Stern flow modelling in transpiration problem125
Tdyn calculation files description.............................. 128
Problem files description................................................... 129
Executing Tdyn Solver........................................................... 130
References.................................................................................... 134
This is the reference manual of the program Tdyn. It consists of four parts,
Introduction, where the user can find the general aspects of the program.
The second part, Tdyn Reference, gives an explanation of every option available in Tdyn.
The third part, gives some recommendations about the best use of Tdyn.
The fourth part, is only intended for experienced users, and gives some details about the internal operation of the environment.
In this manual, different kinds of fonts are used to help the users follow all the possibilities offered by the program Tdyn:
In the following, a menu sequence will be indicated by the symbol '>' (i.e. Data>Problem type>tdyn2d corresponds to the menu sequence shown in Figure 2).
An option or tag available in a menu will be indicated by the symbol '|' (i.e. Fluid | Concentration Properties | Initial I refers to the property Initial I that appears under the tag Concentration Properties in the Fluid window of Tdyn).