Numerical Simulation of Heat Transfer and Thermal Management in High-Power LED Systems for Outdoor Lighting in Nigerian Climate Conditions

Background: High-power LED luminaires suffer accelerated lumen depreciation and premature failure in tropical climates due to elevated ambient temperatures that compromise thermal management. Optimised thermal design is essential for Nigerian outdoor lighting applications. Aim: This study numerically simulated heat transfer in high-power LED systems and optimised thermal management designs for outdoor lighting in Nigerian ambient temperature conditions. Methods: Finite element thermal simulation was conducted using ANSYS Fluent for a 100W LED module with three heat sink geometries: pin fin, cross-cut, and spiral. Ambient temperatures from 25 to 45 degrees Celsius were simulated. LED junction temperature, thermal resistance, and predicted L70 lifespan were computed for each design across a range of natural and forced convection conditions. Results: The spiral fin heat sink reduced junction temperature by 12 degrees Celsius compared with the standard pin fin design at 40 degrees Celsius ambient, reducing thermal resistance from 1.8 to 1.1 K/W. Predicted L70 lifespan increased from 42,000 to 68,000 hours. Forced convection of 1 m/s provided a further 6 degrees Celsius reduction. Conclusion: Spiral fin heat sinks are recommended for high-power LED outdoor luminaires in tropical Nigerian conditions. Municipal street lighting procurement specifications should incorporate thermal performance requirements appropriate to local climate. Keywords: LED thermal management, heat sink, finite element simulation, Nigerian climate, outdoor lighting.