Thermo-fluid dynamic analysis of a cooling system for an inclined plate

• A thermo-fluid dynamic cooling system for an inclined plate subjected to solar heat flux is investigated. • Three modelling approaches are compared: 1D analytical model, CFD fluid film model, and full 3D VOF simulation. • The VOF model accurately captures jet impingement and water film formation on the cooled surface. • The simplified fluid film model provides thermal predictions comparable to VOF with significantly reduced computational cost. • Numerical predictions show very good agreement with experimental measurements, with maximum temperature differences below 1.31°C and mean absolute errors lower than 1°C, confirming the accuracy of the proposed CFD approach. Inclined plates equipped with nozzle systems for wall cooling and cleaning are employed in a wide range of industrial applications, including the metallurgical, nuclear, energy, and marine sectors. Although jet-based cooling has been widely investigated, detailed multiphase simulations are often computationally expensive and difficult to validate experimentally. In this context, a detailed investigation of the thermo-fluid dynamic behavior of the jet distribution, impact, and plate cooling process is essential. In this study, Computational Fluid Dynamics (CFD) simulations were performed to accurately capture the physics of the problem and realistically predict the resulting flow and heat transfer phenomena. The aim of this work is twofold: first, to analyze in detail different physical modeling approaches, ranging from a simplified one-dimensional model to a more compact and comprehensive one that accounts for jet dynamics; second, to compare the obtained results to assess the robustness of an intermediate model representing the optimal trade-off between computational cost and accuracy. Finally, the numerical predictions were validated against experimental data, showing maximum temperature deviations below 1.31°C and mean absolute errors lower than 0.79°C. This demonstrates that a simplified CFD approach can reliably reproduce the thermal behavior of more complex multiphase models while significantly reducing the computational cost. This contribution provides a validated and efficient methodology for thermal analysis and design of jet-cooled inclined surfaces at engineering scale.