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Articles 1 - 8 of 8
Full-Text Articles in Engineering
The Next Generation Router System Cooling Design, Garrett A. Glover
The Next Generation Router System Cooling Design, Garrett A. Glover
Master's Theses
Advancements in the networking and routing industry have created higher power electronic systems which dissipate large amounts of heat while cooling technology for these electronic systems has remained relatively unchanged. This report illustrates the development and testing of a hybrid liquid-air cooling system prototype implemented on Cisco’s 7609s router. Water was the working fluid through cold plates removing heat from line card components. The water was cooled by a compact liquid-air heat exchanger and circulated by two pumps. The testing results show that junction temperatures were maintained well below the 105°C limit for ambient conditions around 30°C at sea level. …
Numerical Simulation Of Gas-Phonon Coupling In Thermal Transpiration Flows, Xiaohui Guo, Dhruv Singh, Jayathi Murthy, Alina A. Alexeenko
Numerical Simulation Of Gas-Phonon Coupling In Thermal Transpiration Flows, Xiaohui Guo, Dhruv Singh, Jayathi Murthy, Alina A. Alexeenko
PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems
Thermal transpiration is a rarefied gas flow driven by a wall temperature gradient and is a promising mechanism for gas pumping without moving parts, known as the Knudsen pump. Obtaining temperature measurements along capillary walls in a Knudsen pump is difficult due to extremely small length scales. Meanwhile, simplified analytical models are not applicable under the practical operating conditions of a thermal transpiration device, where the gas flow is in the transitional rarefied regime. Here, we present a coupled gas-phonon heat transfer and flow model to study a closed thermal transpiration system. Discretized Boltzmann equations are solved for molecular transport …
Radiation And Convection Heat Transfer In Wildland Fire Environments, David J. Frankman
Radiation And Convection Heat Transfer In Wildland Fire Environments, David J. Frankman
Theses and Dissertations
Wildland fire research has been extensive and on going since before 1950. The motivation behind this research is to prevent loss of property and lives. In spite of this research, the heat transfer of fuel ignition and flame spread is not well understood. This dissertation seeks to fill gaps in this understanding through modeling and also by experimentation. The effect of water vapor on the transmission of thermal radiation from the flame to the fuel was investigated. The Spectral Line Weighted-sum-of-gray-gases approach was adopted for treating the spectral nature of the radiation. The study reveals that water vapor has only …
Heat Transfer In Electroosmotic Flow Of Power-Law Fluids In Micro-Channel, Omkareshwar Rao Bakaraju
Heat Transfer In Electroosmotic Flow Of Power-Law Fluids In Micro-Channel, Omkareshwar Rao Bakaraju
ETD Archive
The present study examines heat transfer in electro-osmotic flow of power-law fluids in a micro-channel analytically. The boundary layer equations governing the flow of power-law fluids in a micro-channel have been solved. Heat transfer characteristics such as the temperature distribution and Nusselt number are presented for parametric values of electro-kinetic parameter kH(where k-1 is the Debye length and H is semi-channel height of the micro-channel) and Brinkman number. Uniform surface heat flux boundary condition has been considered. The effects of the Brinkman number on the Nusselt number for specific values of the flow behavior index (n) are analytically determined. This …
Effect Of Rib Turbulators On Heat Transfer Performance In Stationary Ribbed Channels, Aravind Rohan Sampath
Effect Of Rib Turbulators On Heat Transfer Performance In Stationary Ribbed Channels, Aravind Rohan Sampath
ETD Archive
The thermal performance was examined computationally for the stationary channels with rib turbulators oriented at 90 degrees. Ribs were placed on opposite walls and the heat transfer coefficients and frictional loss were calculated. Three stationary channels with aspect ratios (W/H) 1, 2 and 4 were considered for the analysis. The thermal performance was measured by calculating the Nusselt number and frictional losses. Square ribs (w/e = 1) were considered as the baseline configuration. The rib width and rib spacing varies while the rib height is maintained constant. Rib spacing (P/e) of 10 and 20 and rib width to rib height …
Laser Assisted Friction Stir Welding: Finite Volume Method And Metaheuristic Optimization, Shivani Daftardar
Laser Assisted Friction Stir Welding: Finite Volume Method And Metaheuristic Optimization, Shivani Daftardar
LSU Master's Theses
Friction Stir Welding (FSW) is a solid state joining process that uses a non-consumable rotating welding tool to generate frictional heat at the welding location. Large forces are required to produce friction between the welding tool and the work piece which increases the wear rate of the welding tool in welding materials with high melting temperature. Several different approaches have been developed to address this problem. This thesis focuses on a new modification of friction stir welding, called Laser Assisted Friction Stir Welding, a process developed in the last decade. This process uses laser energy to preheat the work piece …
Development Of Novel Microwave Cooking Model For Not-Ready-To Eat Foods, Sohan Birla, Krishnamoorthy Pitchai, Jeyamkondan Subbiah, David D. Jones
Development Of Novel Microwave Cooking Model For Not-Ready-To Eat Foods, Sohan Birla, Krishnamoorthy Pitchai, Jeyamkondan Subbiah, David D. Jones
Department of Biological Systems Engineering: Conference Presentations and White Papers
Recently safety of microwave cooked food has come under scrutiny because of recent outbreak and recalls associated with some of these not-ready-to-eat (NRTE) frozen foods. Heating uniformity of these foods is paramount in rendering the foods safe for consumption. Degree of uneven microwave heating is influenced by both microwave oven and characteristics of food load which decides the electric field distribution within the food load. Given the complexity of parameters, a computer model is always desirable to optimize heating uniformity by proper selection of food shape, proportions, plating, packaging selection and more. Earlier many researchers have made one or more …
Pressure Drop And Endwall Heat Transfer Effects Of Porous Turbulators In A Rectangular Channel, Jared Pent
Pressure Drop And Endwall Heat Transfer Effects Of Porous Turbulators In A Rectangular Channel, Jared Pent
Electronic Theses and Dissertations
This study examines the local and averaged endwall heat transfer effects of a staggered array of porous pin fins within a rectangular channel. The porous pin fins were made from aluminum and had a pore density of 10 pores per inch (PPI). The pressure drop through the channel was also determined for several flow rates and presented in terms of the friction factor. Local heat transfer coefficients on the endwall were measured using Thermochromic Liquid Crystal (TLC) sheets recorded with a charge-coupled device (CCD) camera. Static and total pressure measurements were taken at the entrance and exit of the test …