Optimisation of Spark Plug Material in Petrol and CNG Bi-Fuel Engines

Joseph Onesmo Mrema; Bertram Kiswaga

doi:10.56201/ijemt.vol.11.no10.2025.pg221.235

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Optimisation of Spark Plug Material in Petrol and CNG Bi-Fuel Engines

Joseph Onesmo Mrema; Bertram Kiswaga

Abstract

This study aims to optimize spark plug electrode materials for petrol–CNG bi-fuel engines by evaluating their thermal and structural performance using ANSYS simulation. The research specifically analyzed Iridium alloy, Platinum, and Silicon Nitride under combustion conditions characterized by peak petrol temperatures of 820-870 °C and CNG temperatures of 900–980 °C, with pressures ranging from 4 to 6 MPa. Simulation parameters included total deformation, equivalent (Von Mises) stress, and strain energy as quantifiable variables to assess mechanical resilience and durability. Results showed that Iridium alloy exhibited the lowest total deformation (1.374×10?² mm in petrol and 1.3751×10?² mm in CNG) and the lowest strain energy (6.16×10?³ MJ in petrol and 6.33×10?³ MJ in CNG), indicating superior dimensional stability and fatigue resistance. Although it experienced higher equivalent stress (37.82 MPa in petrol and 35.51 MPa in CNG), this remained well within its strength limits, confirming its robustness. By comparison, Platinum showed higher deformation (?1.39×10?² mm) and moderate strain energy (?6.46×10?³ MJ), while Silicon Nitride absorbed the most strain energy (?7.2×10?³ MJ) but risked brittle fracture under cyclic loading. These findings establish Iridium alloy as the most reliable material for enhancing ignition reliability and extending spark plug service life in bi-fuel engines, contributing to improved fuel efficiency, reduced maintenance costs, and more sustainable automotive performance.

Keywords

spark plugPetrol-CNG Bi-Fuel EngineOptimisationMaterial PropertiesThermal PropertiesDurabilityMechanical Strength

References

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Optimisation of Spark Plug Material in Petrol and CNG Bi-Fuel Engines

Abstract

Keywords

References

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