Fabrication of nanostructured samples for the investigation of near field radiation transfer

Download

index.pdf

Date

2012

Author

Artvin, Zafer

Metadata

Show full item record

Item Usage Stats

262
views

108
downloads

Radiative heat transfer in nanostructures with sub-wavelength dimensions can exceed that predicted by Planck's blackbody distribution. This increased effect is due to the tunneling of infrared radiation between nanogaps, and can allow the eventual development of nano-thermo-photo-voltaic (Nano-TPV) cells for energy generation from low temperature heat sources. Although near field radiation effects have been discussed for many years, experimental verification of these effects is very limited so far. In this study, silica coated silicon wafer sample chips have been manufactured by using MEMS fabrication methods for testing the near field radiation effects. A variety of samples with 1×1, 2×2 and 5×5 mm2 area, and with 25 nm, 50 nm, 100 nm and 200 nm (nano-gap) separations have been prepared. 3D structures with vacuum gaps have been obtained by bonding of the silica coated wafers. The samples have been tested in an experimental setup by a collaborative group at Özyegin University, İstanbul. An increase in the net radiation heat transfer with decreasing nano-gap size has been reported by the Özyeğin group who used these samples in a parallel study. The thesis outlines the micro-fabrication techniques used for the sample preparation. Also, the manufacturing problems we have faced during this research program are discussed.

Subject Keywords

Nanostructures., Heat, Radiative transfer., Infrared radiation., Microfabrication.

URI

http://etd.lib.metu.edu.tr/upload/12614826/index.pdf
https://hdl.handle.net/11511/21782

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Fabrication of silicon carbide-on-silcon based devices for effective near-field thermal radiation transfer Elçioğlu, Elif Begüm; Okutucu Özyurt, Hanife Tuba; Mengüç, M. Pınar; Department of Mechanical Engineering (2018) Near-field radiative transfer (NFRT) has attracted attention due to the potential of obtaining improved amount of heat transfer between media separated by distances comparable to or smaller than the dominant wavelength of emission. Such potential has been demonstrated in vacuum environments to form the basis of mainly near-field thermophotovoltaic systems and further, conversion into electricity with high system efficiency. In this thesis, an analytical analysis is performed to gain insight on nearfield rad...
EVALUATION OF FLUX MODELS FOR RADIATIVE-TRANSFER IN RECTANGULAR FURNACES Selçuk, Nevin (1988-07-01) Three flux-type models for three-dimensional radiative heat transfer were applied to the prediction of the radiative flux density and the source term of a box-shaped enclosure problem based on data reported previously on a large-scale experimental furnace with steep temperature gradients. The models, which are a six-term discrete ordinate model and two Schuster-Schwarzschild type six-flux models, were evaluated from the viewpoints of both predictive accuracy and computational economy by comparing their pred...
Analysis of Transient Laminar Forced Convection of Nanofluids in Circular Channels Sert, İsmail Ozan; Sezer Uzol, Nilay; Güvenç Yazıcıoğlu, Almıla; Kakaç, Sadık (2012-11-15) In this study, forced convection heat transfer Characteristics of nanofluids are investigated by numerical analysis of incompressible transient laminar flow in a circular duct under step change in wall temperature and wall heat flux. The thermal responses of the system are obtained by solving energy equation under both transient and steady-state conditions for hydrodynamically fully developed flow. In the analyses, temperature dependent thermo-physical properties are also considered. In the numerical analys...
EXPERIMENTAL AND NUMERICAL STUDY ON HEAT TRANSFER PERFORMANCE OF SQUARE, CYLINDRICAL AND PLATE HEAT SINKS IN EXTERNAL TRANSITION FLOW REGIME İnci, Aykut Barış; Bayer, Özgür (2019-01-01) Geometrical optimization of heat sinks with square, cylindrical and plate fins for heat transfer increase is numerically analyzed in transition regime external flow. The relations between the thermal characteristics of fins and boundary conditions such as free-stream velocity are investigated. Experimental studies are performed by using manufacturable fins to validate the numerical model. Heat transfer correlations are derived in order to determine average heat transfer coefficients over a certain range of ...
Accuracy of Monte Carlo method re-examined on a box-shaped furnace problem Erturk, H; Arinc, F; Selçuk, Nevin (1997-07-01) Monte Carlo method was applied to predictions of radiative heat flux density and source term of a box-shaped enclosure problem based on data reported previously on a large scale experimental furnace with steep temperature gradients typically encountered in industrial furnaces. The rectangular furnace under consideration has black interior walls and an absorbing emitting medium of constant properties. The predictive accuracy of the model was evaluated by comparing its predictions with exact numerical solutio...

Citation Formats

Z. Artvin, “Fabrication of nanostructured samples for the investigation of near field radiation transfer,” M.S. - Master of Science, Middle East Technical University, 2012.