Silent Dynamics

Author: Hong Kong

  • Virtueller Schleppkanal

    Virtual Towing Tank

    We also perform simulations with our programs on your behalf. Please refer to our price list, to find out the costs.

  • Seegangsverhalten

    Ocean behavior

    The analysis of the sea keeping is performed using potential codes. It includes the calculation of response amplitude operators (RAOs) for all degrees of freedom. These RAOs are used to calculate accelerations, velocities, motion sickness and other parameters at different locations.

    The simulations are carried out with the open source tools PDstrip or NEMOH. The required input is compatible with the input for the ship resistance analysis.

  • Propellerentwurf

    Propeller design

    We perform basic performance analysis and design of turbomachinery using state-of-the-art CFD methods. The entire analysis workflow is fully automated in the InsightCAE framework and uses only open source software. This enables very cost-effective simulations, short turnaround times and easy integration into automated optimization frameworks.

  • Faserverbund-Propellerflügel

    Fiber composite propeller blade

    Propellers with blades made of fiber composite materials (e.g., CFRP or GFRP) are flexible. During design, the deformation of the blades under operating load must be taken into account. We have developed a software solution to perform the necessary CFD simulations with fluid-structure coupling using OpenFOAM and Code_Aster.

  • Kavitation

    Cavitation

    Cavitation is a limiting phenomenon for turbomachinery operating in fluids. CFD simulation is the most reliable method for predicting the onset of cavitation and its effects on machine performance.

  • Propulsionsanalyse

    Propulsion Analysis

    After determining a propeller open water curve using CFD or another calculation method, further analysis, e.g. propulsion analysis, is required to predict the propulsion performance for a specific vessel. We have developed analysis software solutions for seamless integration into the design process, relying exclusively on open source software.

  • Hochgeschwindigkeits-Gleitboote

    High Speed Planing Craft

    The simulation of high-speed planing ships is a challenge with VOF methods. This is because several numerical problems occur at high speeds. We have implemented solutions for this and are able to deliver reliable results in a short time at low cost.

  • Schiffswiderstand

    Ship resistance

    With our InsightCAE Framework, we offer fully automated ship resistance calculations using exclusively open-source CFD software. This not only eliminates software license costs, but also enables users with little specialized knowledge to perform the rather complicated CFD analyses thanks to the automation.

  • Exporting von STEP Dateien mit benannten Oberflächen aus PTC CREO

    Exporting STEP files with named surfaces from PTC Creo

    When preparing geometry for numerical simulations, it is often required to mark individual surfaces in the model. These surfaces can then be used, for example, as an inlet or for applying forces and pressures in a structural simulation.

    The STEP format supports named entities. The question is: how to set the names in the CAD program? And how to achieve that they are actually stored in the STEP file? In the following, these questions are answered for the software PTC Creo.

    Name Surfaces

    Select “File” > “Prepare” and then “Open Model Properties”, then select “Names” in the model properties dialog:

    You can then select faces by clicking on them and enter a name in the dialog box:

    PTC Creo assign name to face or surface

    Exporting Names in STEP File

    If you export an STP file with the default settings, the names will not be stored in the file. You need to change the export setup for them to be kept.

    Open the settings dialog via “File” > “Options”. Then navigate to “Configuration Editor”. Here, you need to add the option “intf_out_assign_names” and set it to “user_name”.

    PTC Creo STEP export settings

    Accessing Named Entities in ISCAD

    It is now possible to access faces through their assigned names, e.g., in ISCAD. Once the STEP file is imported, its sub-entities can be explored by typing Ctrl-I (see below). The named faces appear as “face_” in the hierarchy:

    InsightCAE ISCAD import STP with named faces

  • Vector Analysis in the Bash Shell

    When performing preparatory operations for CFD or FEM analyses, for example, it is often necessary to specify vector parameters. Vector constants are easy to handle:

    myMesh --direction "$1 0 0"

    However, it quickly becomes complicated if the vectors have to be manipulated, e.g. multiplied by scalars or rotated.

    A powerful solution is to use the Matlab Octave clone to perform the operations. Two features of Octave are useful in this context:

    • the command-line option “--eval” to specify the expression to handle
    • The `disp` function outputs results in a plain format on a single line.

    Here's the translation: An example:

    DIR="1 0 0"
VELOCITY=$(octave --eval "disp( 11.*[$DIR] )")

myMesh --direction "$DIR"
mySolver --velocity "$VELOCITY"

    More complicated operations are possible, though one needs to take care to produce line vectors as results. Rotation is an example:

    DIR="1 0 0"
ANG=45

DIR_ROT=$(octave --eval "pkg load linear-algebra; disp( (rotv([0 0 1], $ANG*pi/180)*[$DIR]')' )")

myMesh --direction "$DIR_ROT"