Simulation-Based Evaluation of a Suzuki GSX-R750 Engine Piston for Formula Student Applications Using CMM-Derived Geometry

This thesis presents a high-fidelity modelling framework for predicting the thermo-structural behaviour of a modified piston assembly. The study focuses on a Suzuki GSX-R750 engine, adapted by the University’s Formula Student team through a shortened stroke configuration to achieve a displacement of 708 cc. The methodology integrates experimental metrology, advanced combustion modelling, and non-linear finite element analysis (FEA) to simulate operating conditions with improved accuracy. To address manufacturing variability, coordinate measurement machine (CMM) data from four pistons, each with multiple measurement sets, were processed and averaged to obtain a representative skirt geometry. This approach ensured that the finite element model captured as-manufactured features rather than relying solely on nominal CAD dimensions. The combustion loading model was refined through calibration of the Wiebe function parameters the efficiency factor (a) and shape parameter (m) along with the polytropic index. These adjustments produced in-cylinder pressure traces consistent with 1D CFD model behaviour and enabled the derivation of realistic temperature fields and heat transfer coefficients at the piston crown. The integrated model, incorporating both measured geometry and calibrated boundary conditions, was executed in MSC Marc Mentat for coupled thermal and structural simulations. The analysis included crown temperature distribution, skirt deformation, thrust forces, and contact forces with the liner, as well as stress concentrations in critical regions such as the pin bore and ring grooves. Results aligned with expected performance thresholds, demonstrating the reliability of the modelling approach. The key contributions of this work are threefold: (1) a systematic methodology for consolidating multi-set CMM data into robust simulation inputs, (2) a refined thermodynamic loading model based on tuned Wiebe parameters and polytropic coefficients, and (3) a validated workflow for coupled thermo-structural analysis of piston assemblies under racing conditions. Together, these outcomes provide actionable insights into thermal hotspots, deformation behaviour, and piston-liner interactions, directly supporting design optimization for durability and efficiency in Formula Student applications.