Geodise Component – CAD system
Overview
Wenbin Song
Email: w.song@soton.ac.uk
Geodise Project, e-Science Centre
School of Engineering Sciences
University of Southampton
Aim – provides robust parametric CAD models for CFD simulation;
Requirements for CAD models
Data flows and problem specific data definition
RR Negatively Scarfed Engine Intake
© Geodise Project, University of Southampton, 2003.
http://www.geodise.org/
Geodise Component – CAD system
Requirements for CAD model:
Parametric: ability to respond automatically to the latest parametric changes;
Generic: ability to produce different geometries from one model;
Robust: low rate of failure for combinations of parameters
Pro/Engineer
ICAD
FEM (ANSYS, SC03)
CFD (Fluent, Hydra)
Unigraphics
Cost estimation
IGES/STEP, CADfix
© Geodise Project, University of Southampton, 2003.
http://www.geodise.org/
Geodise Component – CAD system
Dataflow in simulation
CAD
Command script
Condor, Grid/Web service
Meshing
Command script
Condor, Grid/Web service
Pro/E model part file;
Trail file;
Input data file;
Solver
Command script
Condor; Grid/Web service
CADfix:
Seamless geometry exchange
is not effortless, but often
problematic, usually requires
repairs: - solution is robust
modelling in CAD systems,
such as avoiding very short
entities, etc.
IGES/STEP file;
Gambit Journal file;
Mesh file;
Fluent journal file;
© Geodise Project, University of Southampton, 2003.
http://www.geodise.org/
Geodise Component – CAD system
Availability of CAD system:
Pro/Engineering (version 2001200 for Windows), running locally;
Model data files for geometry creation:




Model part file (defining the shape paramterization, input parameters, etc.)
Trail file (script file used to generate IGES/STEP file in batch mode);
Input file (text file containing name-value pairs);
Three files need to be in local working directory and and resulting IGES file is also
stored in it and with the same name;
 MATLAB function proe_iges() running locally generates an IGES file based on input file;
Transfer of IGES/STEP file for mesh generation:
 Use of gd_putfile to transfer geometry file and Gambit journal file onto remote server;
© Geodise Project, University of Southampton, 2003.
http://www.geodise.org/
Geodise Component – CAD system
Application One: Negatively Scarfed Engine
Intake (Rolls-Royce)
Problems definition: maximize noise reduction
without (significant) loss aerodynamic
performance for all operating conditions.
Parameters:
Intake geometry is defined using Pro/E by a list of parameters,
parameters that are expected to be used in optimisation are
listed below:
Scarf_angle = 10 (degree), shown as d1 (d1=90-scarf_angle)
in the following figure;
Top_radius = 1243 (mm), shown as d220;
Bottom_radius = 1390 (mm), shown as d221;
Side_radius = 1430 (mm), not shown;
Fanface_radius = 1241 (mm), not shown;
Figure: (a) A3XX-100; (b) three dimensional
Fanface_axial_distance = 1818.43 (mm), shown as d2;
shape of negatively scarfed engine intake;
Center offset = 5 (mm), shown as d5;
(c) parameters of intake vertical layout.
© Geodise Project, University of Southampton, 2003.
http://www.geodise.org/