Numerical investigation of thermal characteristics like temperature distribution , velocity field, stream line, Peclet numbers and Reynolds numbers in Si melt are performed for directional solidification crystal growth processes. One of the greatest technological and scientific challenges of multi-crystalline silicon growth is to achieve homogeneity of the material properties in the grown crystal. It affected by fluctuations of the growth rate of the crystal. One of the possible causes for fluctuations of the growth rate is the instationary convection in the melt. The aim is to examine the influence of the thermal convection effect in the melt. Dimensionless numbers are of key importance in parametric analysis of non-linear complex transport phenomena of bulk silicon growth process. They are also extremely useful in understanding of the heat and mass transfer of fluid flow on Si melt during solidification processes. The flow pattern influences the quality of the crystal through the convective heat and mass transport. The computations are carried out in a 2D/3D axis symmetric model by the finite-element technique. The results indicate that thermal forces have a dramatic effect on the flow of silicon melt. The simulation results are in reasonable agreement with the predictions of the theoretical approach. Kew words: Simulation and modeling; Thermal analysis; Navier-Stokes equations; Solar energy materials; Finite element analysis; 1. INTRODUCTION The unsustainable nature of fossil fuels as an energy source, from the point of view of future availability and environmental impact, has spurred an interest in diversification of energy sources, with particular interest in renewable energy. The photovoltaic (PV) industry is a player... ... middle of paper ... ...anesh, Satoshi Nakano et.al, Effect of crucible rotation on oxygen concentration during unidirectionalsolidification process of multicrystalline silicon for solar cells, Journal of Crystal Growth 311 (2009) 1123–1128 [11] Balaji Devulapalli and Milind S. Kulkarni, Modeling multi-Crystalline Silicon Growth in Directional Solidification Systems, ECS Transactions, 18 (1) 1023-1029 (2009). [12] Sudheer M.Pimputkar and Simon Ostrach ,Convective effects in crystals grown from melt., JournalofCrystalGrowth 55 (1981) 614—646. [13] http://www.comsol.co.in/support/books [14] M.Nacati Ozisik, Heat transfer(a basic approach), McGraw-Hill book company,New york,1985. [15] L. Braescu, and T. F. George , Critical Marangoni numbers and their effect on the dopant distribution in silicon fibers, Int. Jou.of .Math Models and Methods in Applied Sciences, Issue 3, Volume 2, 2008.
"Solar & Wind Energy Calculations: The (very) Basics." Solar-estimate.org. Solar-Estimate, 2013. Web. 25 Nov. 2013.
In other words, the alloying element affects the temperature of which the oxide scale forms and its behaviour is at higher elevation temperature as well as gas composition and moisture level [3].
The Solyndra Company, founded in 2005 by Christian Gronet, designed, manufactured, and sold a unique type of solar panels. They were termed “solar photovoltaic (PV) systems” and were designed for large, flat to low sloped commercial building roofs. The panels were designed to have the best performance when mounted horizontally and to be installed very close together so that they covered a much higher percentage of the roof top thus producing more electricity than the typical flat panel solar panels by comparison. This was created through the production by absorbing light from all directions including indirect and reflected light as well as direct sunlight when combined with a white roof. This was due to the design of having rolled its copper indium gallium selenite or CIGS into a cylindrical shape. Each tube had 40 of them in each 1-meter-by-2-meter panel (Solyndra, 2008).
The molar specific heats of most solids at room temperature and above are nearly constant, in agreement with the Law of Dulong and Petit. At lower temperatures the specific heats drop as quantum processes become significant. The Einstein-Debye model of specific heat describes the low temperature behavior.
When the first crystal of KNO3 appear in the solution recrystallization is occurring. KNO3 is a solid and in water it still remains to its texture. Although once heated and forming to its liquid form letting it cool until crystal begin forming soon after equilibrium was reached. The temperatures when the crystals form as the total volume of solution increased is when crystal are first observed which is when the reaction is at
Many semiconductor materials can melt And they are recrystallized reproducibly in large monocrystal crystals with The help of a seed crystal, as in the Czochralski method Employed in the manufacture of almost all silicon wafers, Allowing reasonably large wafers to be mass produced. How- Because SiC sublimates instead of reasonably melting
... middle of paper ... ... 14 Nov 2011.. http://web.ebscohost.com/lrc/detail?vid=4&hid=110&sid=fef50b1c-4aba-40fd-83b1- 583a32991f55@sessionmgr110&bdata=JnNpdGU9bHJjLWxpdmU=> Edrich, Matthias. The.
Then, the materials cool down slowly. Through this process, the dislocations of the structure reduce. The strength of materials drop and raise the toughness flexibility and ductility. Also, the nucleation and growth will occurs in annealing.
This paper first reviews the metallurgical process of continuous steel slab casting in terms of fluid flow, heat and mass transfers in the manufacture production. Finally, this paper reviews the physical and mathematical modelling in physical experiment and mathematical models, which has been used to study in the process.
Cengel, Y. A., & Boles, M. A. (2011). Thermodynamics: An engineering approach (7th ed.). New York, NY: McGraw-Hill.¬¬¬¬
Rotman, David. "Finding a Solar Solution." Technology Review 2 (2012): 48-51. Print. 22 November 2014.
Melting takes place when a solid gets enough energy to melt. When it gets enough energy it is called the melting point. An example of melting would be snow turning into water. The reverse of the melting process is called freezing. Liquid water freezes and becomes solid ice when the molecules lose a lot of energy. When a solid goes to a gas and skips the liquid, sublimation occurs. The best example of sublimation would be dry ice. Deposition is when a gas goes directly to a solid without going through the liquid phase. An example of deposition is when water vaper turns to tiny crystals.
How Efficient is Solar Energy Technology? Engineering Challenges. n. d. a. d. a. d. d. 8 April 2014. http://www.engineeringchallenges.org/cms/8996/9082.aspx>. How do Nuclear Plants Work?”
Solar water heaters work by using energy from the sun. There are two types of systems for solar water heaters, an open system and a closed system (“Tapping into the Sun”). These systems depend on the type of climates they are installed in (“Tapping into the Sun”). Open systems are worth the installation if the weather is year round sunny, closed systems are better if the weather gets cold. The water cannot be run during winter so the system will be switched to fuel and in the summertime when it is warm, so the sy...
In summary, the rate of cooling from the austenite phase is the main determinant of final structure and properties.