LED lighting still suffers from its thermal problem linked mainly to the increase in junction temperature. The situation becomes more and more aggravated when it comes to decorative lighting. Indeed, this type of lighting application sometimes requires that the heat sink of the LED lamp be integrated into a narrow space, such as false or sloped ceilings, which limits the transfer of heat to the outside. In this context, the current study reports a numerical analysis of natural convection heat transfer around rectangular heat sink for LEDs lighting applications. The radiator is put in an inclined cavity with an orientation angle varying from 0̊ to 60̊. The effects of the enclosure inclination and its length on thermal behavior, flow structure in the cavity as well as on optical properties of the light source were highlighted. The CFD simulation showed a significant effect on the heat transfer rate when varying the cavity length (presented as an aspect ratio A) and its orientation. A = 4 was determined as an optimal cavity aspect ratio, and it was found that higher orientations are more sensitive to the increase of the length of the cavity. For θ = 60̊, the luminous efficiency is ameliorated by about 10% when increasing the cavity length from one to four. Accordingly, we proposed correlations in simple form to predict the heat transfer rate for different configurations studied.

The global development of LED lighting in all applications for both public and indoor lighting establishes a very important lever for reducing the carbon impact by significantly reducing energy consumption. Smart lighting will therefore constitute an essential lever in the smart city of tomorrow. The latter is more sustainable and less energy-intensive than other light sources, contributing towards the Sustainable Development Goals set forth by the United Nations (SDGs 7 and 11). With its ease of integration, ergonomics, lightness, and high quality of light, this innovative light source has two major qualities: its energy efficiency and its long service life. However, poor thermal management has catastrophic effects on these two essential criteria. This necessarily requires optimizing thermal management and heat sinks. In some cases, thermal models and simulations can lead to considerable calculation times because they implement many parameters. This work therefore aims to reduce the number of these simulations by applying the method of experimental designs (Taguchi) and analysis of variance (ANOVA) to simulations intended to optimize the dissipation of LED luminaires. We applied the method to a simple finned heat sink model for a unit input power and then to a concrete case of a high-power LED. The control parameters and their respective contributions in the proposed model were studied. The ANOVA results corroborated the conclusions of the Taguchi method, demonstrating a strong agreement between these analytical methods, in which the temperature was adjusted by identifying optimal combinations of parameters. The fields of application relevant to this study include both indoor lighting (false ceiling) and confined spaces with severe sealing constraints such as car headlights or the optical blocks of urban luminaires.

This paper presents the results of a numerical investigation by design of experiments of the thermal management of a symmetrical rectangular heat sink for LED lighting placed in a cavity with asymmetrical conditions at its opening. Our mathematical model is validated by an experiment we carried out for an LED placed in a cavity. According to the proposed design of experiments (2⁴ factorial designs), we analyzed, by simulation modeling using COMSOL Multiphysics^®, the influence of the different controllable parameters (the position A and width C of the openings, the inlet air velocity B, and the cavity height D) on the evolution of the junction temperature in order to optimize the thermal management of the proposed LED lamp. Using Minitab^® manipulation software, a Pareto analysis and an analysis of variance (ANOVA) were carried out, and mathematical models were deduced to estimate the optimal junction temperature and the convective heat transfer coefficient of the proposed radiator and the surrounding air as a function of the controlled parameters. It was found that the position of the opening is the most influential factor on the junction temperature, with a contribution of 93.46%, followed by the factors velocity and width of the opening, with low contributions (3.22% and 1.24%). We also observe that the height of the cavity and the interactions (A × C, A × D, B × C, B × D, C × D) have no significant influence on the junction temperature.

In this work, we analyze numerically, using Comsol Multiphysics, the influence of four parameters (the power of the lamp, the ambient temperature, the angle of inclination of the lamp and the number of holes in the lamp cavity) on the evolution of the junction temperature of a LED lamp placed in a multi-hole cavity using a fractional factorial plan. Taking into account the results obtained, we optimize our model using the Minitab manipulation software. Thus, a Pareto analysis (ANOVA) is carried out and a mathematical model is deduced to estimate the junction temperature of the LED lamp as function of the controlled parameters. The different influencing factors and especially the relative amplitude of their effect on the temperature of the LED chip could thus be calculated and demonstrated. If the electric power supply of the LED remains the first factor of impact on the temperature, the other parameters as well as the number of holes, the angle of inclination or the ambient temperature could thus be prioritized in order of influence. Then an improved model is provided, and its limit with regard to the cavity's condensation detection was examined showing that the risk of water condensation inside the cavity is only detected in the case where the lamp is exposed in an extremely humid area.

Efficient thermal management of high-power electronic components has become a critical engineering challenge as power densities grow and device geometries shrink. Conventional solutions based on passive heatsinks and mechanical fans are increasingly inadequate in applications where noise, reliability, and compactness are paramount. This paper presents a comprehensive Computational Fluid Dynamics (CFD) investigation of ionic wind—an Electro Hydro Dynamic (EHD) phenomenon in which a corona discharge between asymmetric electrodes generates a directed airflow without any moving part—as an energy-efficient alternative for cooling high-power electronics. A fully coupled 2D Multiphysics model is developed in COMSOL Multiphysics, integrating electrostatics, ion transport (Nernst–Planck), Navier–Stokes fluid dynamics, and convective heat transfer. The 2D formulation, while computationally efficient and consistent with prior EHD modeling studies, neglects lateral jet spreading inherent to a real three-dimensional needle configuration and is therefore expected to overestimate peak impingement velocities; quantitative comparisons with experimental temperatures are interpreted with this limitation in mind. The study focuses on a needle–collector configuration applied to a heated aluminum plate representative of a high-power electronic component such as a Light Emitting Diode (LED), a power transistor, or a microprocessor die. Simulation results are indirectly validated against experimental data obtained by Schlieren optics on a high-power (Chip-On-Board) COB LED system. The ionic wind reduces the maximum surface temperature by 8.1 K and substantially attenuates the central hotspot, redistributing heat laterally. A systematic parametric study reveals that applied voltage and needle height above the heat source are the dominant design parameters, while an energy balance shows that the EHD jet directly evacuates approximately 1.8% of the generated heat—acting primarily as a surface convection enhancer rather than a bulk heat extractor. These findings provide quantitative design guidelines applicable to any power electronic component cooled by an EHD system.

This paper proposes a photometrically consistent real-time rendering pipeline for digital twins of street lighting systems, designed to bridge the gap between offline lighting simulation tools and interactive visualization environments. The approach integrates high-resolution illuminance data generated by Relux and DIALux into a real-time graphics engine, with the objective of preserving photometric fidelity while maintaining interactive performance. The proposed framework is demonstrated on a campus road section through a street lighting digital twin implemented in Unity. A modular rendering pipeline is introduced, including photometric data preprocessing, illuminance-grid interpolation, texture generation, and consistency checks between offline simulations and real-time outputs. Three real-time lighting modes are implemented and evaluated: an analytical cone-based spotlight model, a texture-masked cookie spotlight mode, and a full-resolution photometric sampling approach based on Unity’s universal Render Pipeline (URP) Shader Graph. A static validation between Relux and DIALux confirms consistent photometric inputs, with mean absolute errors below 5%. Evaluation results show that richer photometric sampling improves agreement with the Relux reference: the Shader Graph mode achieves the best in-engine luxmeter validation (root mean square error (RMSE) 3.82 lx, Pearson correlation (Corr) 0.705) while sustaining real-time performance at approximately 140 frames per second (FPS). Overall, the proposed pipeline enables aligned and interactive street lighting digital twins suitable for simulation-driven visualization and evaluation.