Effects of optical design modifications on thermal performance of a highly reflective HfO2/SiO2/TiO2 three material coating

Date

2018-02-01

Author

OCAK, M.
Sert, Cüneyt
Okutucu-Ozyurt, T.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

168
views

0
downloads

Effects of layer thickness modifications on laser induced temperature distribution inside three material, highly reflective thin film coatings are studied with numerical simulations. As a base design, a 21 layer coating composed of HfO2, SiO2 and TiO2 layers of quarter wave thickness is considered. First, the laser induced temperature distribution in this base design is obtained. Then the layer thicknesses of the base design are modified and the corresponding temperature distributions in four alternative non-quarter wave coatings are evaluated. The modified thicknesses are determined using an in-house code developed to shift the electric field intensity (EFI) peak from the first high/low layer interface towards the adjacent low index layer that has a higher thermal conductivity, hence, higher laser damage resistance. Meanwhile, the induced increase in the EFI peak is kept at a user defined upper limit. The laser endurance of the base and alternative designs are compared in terms of their estimated temperature distributions. The results indicated that both the peak temperature and the highest interface temperature are decreased by at least 32%, in non-dimensional form, when alternative designs are used instead of the base design. The total reflection of the base design is only decreased from 99.8% to at most 99.4% when alternative designs are used. The study is proved to be successful in improving the laser endurance of three material thin film coatings by lowering the peak and interface temperatures.

Subject Keywords

General Engineering, Condensed Matter Physics, Fluid Flow and Transfer Processes

URI

https://hdl.handle.net/11511/43606

Journal

HEAT AND MASS TRANSFER

DOI

https://doi.org/10.1007/s00231-017-2147-8

Collections

Department of Mechanical Engineering, Article

Suggestions

OpenMETU
Core

Effect of variable thermal conductivity and viscosity on single phase convective heat transfer in slip flow KAKAÇ, SADIK; Güvenç Yazıcıoğlu, Almıla; Gozukara, Arif Cem (Springer Science and Business Media LLC, 2011-08-01) For a variety of fields in which micro-mechanical systems and electronic components are used, fluid flow and heat transfer at the microscale needs to be understood and modeled with an acceptable reliability. In general, models are prepared by making some extensions to the conventional theories by including the scaling effects that become important for microscale. Some of these effects are; axial conduction, viscous dissipation, and rarefaction. In addition to these effects, temperature variable thermal cond...
Modeling of particle-resin suspension impregnation in compression resin transfer molding of particle-filled, continuous fiber reinforced composites Sas, Hatice Sinem; Erdal Erdoğmuş, Merve (Springer Science and Business Media LLC, 2014-03-01) A particle-resin suspension impregnation model is used for analyzing the mold filling process in compression resin transfer molding (CRTM) of particle-filled, continuous fiber composites. The model is based on Darcy flow coupled with particle filtration and is applicable to two-dimensional impregnation through isotropic/anisotropic fiber preforms. Comparisons with simple analytical solutions and experimental results from the literature were made to validate the numerical solution. Simulations showed that CR...
An experimental investigation on performance of annular fins on a horizontal cylinder in free convection heat transfer Yildiz, S; Yüncü, Hafit (Springer Science and Business Media LLC, 2004-02-01) Natural convection heat transfer in annular fin-arrays mounted on a horizontal cylinder was experimentally investigated. An experimental set-up was constructed to investigate heat transfer characteristics of 18 sets of annular fin-arrays mounted on a horizontal cylinder of 24.9-mm diameter in atmospheric conditions. Keeping the fin thickness fixed at 1 mm, fin diameter is varied from 35 mm to 125 mm and fin spacing is varied from 3.6 mm to 31.7 mm. The base-to-ambient temperature difference was also varied ...
Optimization of Vortex Promoter Parameters to Enhance Heat Transfer Rate in Electronic Equipment Ayli, Ece; Bayer, Özgür (ASME International, 2020-04-01) In this paper, optimization of the location and the geometry of a vortex promoter located above in a finned surface in a channel with eight heat sources is investigated for a Reynolds number of 12,500 < Re < 27,700. Heat transfer rates and the corresponding Nusselt number distributions are studied both experimentally and numerically using different vortex promoter geometries (square, circular, and triangular) in different locations to illustrate the effect of vortex promoter on the fluid flow. Optimization ...
Experimental Thermal Performance Characterization of Flat Grooved Heat Pipes Alijani, Hossein; ÇETİN, BARBAROS; Akkus, Yigit; Dursunkaya, Zafer (Informa UK Limited, 2019-06-15) The thermal characterization of aluminum flat grooved heat pipes is performed experimentally for different groove dimensions. Three heat pipes with groove widths of 0.2 mm, 0.4 mm, and 1.5 mm are used in the experiments. The effect of the amount of the working fluid is extensively studied for each groove width. The results reveal that, although all three succeed in dissipating the heat input through the phase change of the working fluid by continuous evaporation and condensation, the effectiveness of the he...

Citation Formats

M. OCAK, C. Sert, and T. Okutucu-Ozyurt, “Effects of optical design modifications on thermal performance of a highly reflective HfO2/SiO2/TiO2 three material coating,” HEAT AND MASS TRANSFER, pp. 377–384, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/43606.