CATIA radial engine simulation

Overview

A personal CAD and kinematics project recreating a five-cylinder radial aircraft engine in CATIA V5. Working from an online engineering drawing as reference, each component was modeled in 3D and assembled, then the full engine cycle was simulated with DMU Kinematics to validate the mechanism.

Key highlights

• Modeled the crankshaft, master and link rods, pistons, and finned cylinders from a reference drawing.
• Assembled the full five-cylinder radial engine with correct joint constraints.
• Simulated the complete engine cycle using DMU Kinematics to demonstrate assembly motion.
• Validated mechanism behavior and checked for interference during motion.

What I learned

• Assembly Architecture for Simulation: Discovered that DMU Kinematics requires a flat product structure. Successfully decoupled the simulation environment from the static CAD environment by dismantling sub-assemblies into root-level components and managing dedicated kinematic file copies.
• Parametric Control (Variables & Design Tables): Built an intelligent, flexible model by linking dimensions to Variables and Design Tables. This allows critical engine configurations to be updated automatically across the assembly via a spreadsheet without manual remodeling.
• Mathematical Motion (Laws): Progressed from manual keyframe animations to true engineering simulation by writing time-based Kinematic Laws to drive the main shaft, accurately simulating engine RPM and stroke timing.
• Kinematic Joint Hierarchy: Mastered the precise application of DMU joints, distinguishing between permanent sub-assemblies (Rigid joints for piston rings and pressed pins), linear sliding (Prismatic joints for cylinders), and single-plane pivots (Revolute joints for connecting rods).
• Mechanism Diagnostics: Learned to actively read CATIA's Mechanism Analysis tools to hunt down rogue degrees of freedom (e.g., isolating floating rotational axes) rather than guessing why an assembly wouldn't simulate.