Airfoil Wing Design in CATIA V5

Overview

This project demonstrates the parametric modeling of an aircraft wing using CATIA V5, where airfoil coordinate data was imported through an Excel-based CATIA macro. The objective was to design a three-section lofted wing with controlled taper, sweep, and section transitions, essential parameters in preliminary aircraft design.

Design Parameters

Section	Chord Length	Position (mm)	Sweep Offset (mm)	Notes
Root	200 mm	0	0	Base airfoil section
Mid	150 mm	400	0	Linear taper transition
Tip	50 mm	1200	25	12.4° swept trailing edge

• Taper Ratio: 0.25
• Sweep Angle: 12.4°

Design Process

1. Airfoil Data Extraction

• Airfoil coordinate data downloaded as .csv from AirfoilTools.com
• Three spanwise sections defined:
  • airfoil_root.csv
  • airfoil_mid.csv
  • airfoil_tip.csv
• Each .csv file contains X–Y coordinate pairs representing the airfoil surface.

2. Excel Macro Automation

• The Excel workbook GSD_PointSplineLoftFromExcel.xlsm includes a built-in CATIA macro (VBA).
• The macro automates:
  • Import of .csv data into Excel.
  • Communication with CATIA via CATIA API.
  • Creation of 3D points and splines from the airfoil data directly inside CATIA.
• The macro was executed for all three airfoil sections (root, mid, and tip).

Result: Each section appears in CATIA as a clean spline curve representing its airfoil profile.

3. Wing Construction in CATIA

• Each spline was:
  • Scaled according to the chord length (200, 150, and 50 mm).
  • Positioned at the correct spanwise location:
    • Root at 0 mm
    • Mid at 400 mm
    • Tip at 1200 mm
  • Tip airfoil translated 25 mm aft to introduce 12.4° sweep.
• The Multi-Section Surface (Loft) tool was used in the Generative Shape Design (GSD) module to connect the three airfoil profiles into a smooth 3D wing surface.

4. Lofting and Verification

• The lofted surface was checked for:
  • Smoothness and continuity.
  • Proper alignment of section edges.
  • Correct geometric scaling and sweep.
• The resulting wing geometry was saved as airfoil.CATPart.

Visual Results

Preview

Root section

Mid section

Tip section

What I Learned

• Understanding the relationship between taper ratio, sweep angle, and spanwise geometry.
• Handling coordinate-based modeling and precision scaling of airfoil sections.
• Constructing multi-section lofts with smooth aerodynamic surfaces.

Tools Used

• CATIA V5 for Airfoil and wing 3D modeling
• Excel (VBA) for CATIA macro execution and spline generation
• AirfoilTools.com for Airfoil coordinate database
• CSV Data for Raw coordinate input for airfoils

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✨ This project is part of my mechanical design portfolio — exploring advanced aerodynamic components using CATIA V5.