Novel Ideas for Thermal Management of Filament LED Light Bulbs

Maaspuro, Mika

doi:10.3991/ijoe.v17i08.23695

Cited by 4 publications

(2 citation statements)

References 8 publications

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“…LED bulbs have been made for replacements for incandescent bulbs having electric power up to 60 W or 75 W. Typical LED replacements have power from 9 W to 11.5 W. Cooling technologies can either be passive or active. Active technologies are liquid, jet impingement, electro-mechanical fan, microspray, ionic wind, piezoelectric fan [1], or thermoelectric cooling [2]. Passive cooling technologies are heat sinks, heat pipes [3], and thermal interface materials (TEM).…”

Section: Introductionmentioning

confidence: 99%

Thermal Modelling an LED Bulb using IR Thermography and Bayesian Deconvolution

Maaspuro

2022

Int. J. Onl. Eng.

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This study focuses on LED bulbs where LEDs are typically mounted on a metal core printed circuit board. A sample of LED bulbs having base E27 and a power range between 3.5-11.5 W have been measured. A thermal model will be found using thermal transient testing, infrared thermal measurements, and the Bayesian deconvolution. LED surface temperature will be measured without contact using a low-resolution IR imager. A test facility has been built which automatically switches power on and measures and records samples during the measurement cycle which typically lasts around one hour. This time duration was long enough for reaching the thermal steady-state condition. The procedure uses a measured thermal transient, first calculates the thermal impedance Zth, then the time constant spectrum Rζ(z) using the Bayesian deconvolution. An equivalent thermal network model will be found in Foster-presentation. This can be transformed to Cauer-presentation. The model is a driving point model for thermal impedance and includes thermal resistances and thermal capacitances. FEM simulation gives more detailed information about heat transfer paths and internal temperatures of an LED bulb.

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Section: Introductionmentioning

confidence: 99%

Thermal Modelling an LED Bulb using IR Thermography and Bayesian Deconvolution

Maaspuro

2022

Int. J. Onl. Eng.

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“…The study optimization was analyzed gene expression data, the evolution algorithm was applied and combined with the advantages of crossover strategy [30], [31]. The finite element method was used to study thermal conditions for different filling gases that have been resolved [32].…”

Section: Introductionmentioning

confidence: 99%

Identification of Flexural Modulus and Poisson’s Ratio of Fresh Femoral Bone Based on a Finite Element Model

Nabudda¹,

Suriyawanakul²,

Tangchaichit³

et al. 2022

Int. J. Onl. Eng.

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Finite element analysis (FEA) is increasingly applied to medicine because it could increase accuracy and rapid outcomes. However, there is a lack of the method to determine Young’s modulus and Poisson’s ratio for fresh femoral bone and the mathematical principle’s optimization for calculating nonuniform configuration. This study aimed to investigate the surrogate model for the optimization method to determine Young’s modulus and Poisson’s ratio of the fresh femoral bone. Young’s modulus and Poisson’s ratio obtained 20 ranked pairs by the Latin hypercube sampling method. The values were calculated in the finite element for root mean square error (RMSE) and were then used for solutions by a quadratic function, radial basis function (RBF), and Kriging (KG). The lowest RMSE value was 0.1518 for the RBF method, with the young’s modulus at 304.4756 and the Poisson’s ratio at 0.3334. The current study identified the RBF technique to determine the properties of the femoral bone. Moreover, the RBF procedure might apply to other long bones because of the comparable nonuniform configuration.

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