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Articles 541 - 552 of 552

Full-Text Articles in Engineering

A Two-Layer Composite Model Of The Vocal Fol Lamina Propria For Fundamental Frequency Regulation, Kai Zhang, Thomas Siegmund, Roger W. Chan Jan 2007

A Two-Layer Composite Model Of The Vocal Fol Lamina Propria For Fundamental Frequency Regulation, Kai Zhang, Thomas Siegmund, Roger W. Chan

School of Mechanical Engineering Faculty Publications

No abstract provided.


Thermally Developing Flow And Heat Transfer In Rectangular Microchannels Of Different Aspect Ratios, Poh-Seng Lee, S V. Garimella Feb 2006

Thermally Developing Flow And Heat Transfer In Rectangular Microchannels Of Different Aspect Ratios, Poh-Seng Lee, S V. Garimella

CTRC Research Publications

Laminar convective heat transfer in the entrance region of microchannels of rectangular cross-section is investigated under circumferentially uniform wall temperature and axially uniform wall heat flux thermal boundary conditions. Three-dimensional numerical simulations were performed for laminar thermally developing flow in microchannels of different aspect ratios. Based on the temperature and heat flux distributions obtained, both the local and average Nusselt numbers are presented graphically as a function of the dimensionless axial distance and channel aspect ratio. Generalized correlations, useful for the design and optimization of microchannel heat sinks and other microfluidic devices, are proposed for predicting Nusselt numbers. The proposed …


A Constitutive Model Of The Human Vocal Fold Cover For Fundamental Frequency Regulation, Kai Zhang, Thomas Siegmund, Roger W. Chan Jan 2006

A Constitutive Model Of The Human Vocal Fold Cover For Fundamental Frequency Regulation, Kai Zhang, Thomas Siegmund, Roger W. Chan

School of Mechanical Engineering Faculty Publications

No abstract provided.


A Novel Hybrid Heat Sink Using Phase Change Materials For Transient Thermal Management Of Electronics, Shankar Krishnan, S V. Garimella, S. S. Kang Jun 2005

A Novel Hybrid Heat Sink Using Phase Change Materials For Transient Thermal Management Of Electronics, Shankar Krishnan, S V. Garimella, S. S. Kang

CTRC Research Publications

A hybrid heat sink concept which combines passive and active cooling approaches is proposed. The hybrid heat sink is essentially a plate fin heat sink with the tip immersed in a phase change material (PCM). The exposed area of the fins dissipates heat during periods when high convective cooling is available. When the air cooling is reduced, the heat is absorbed by the PCM. The governing conservation equations are solved using a finite-volume method on orthogonal, rectangular grids. An enthalpy method is used for modeling the melting/re-solidification phenomena. Results from the analysis elucidate the thermal performance of these hybrid heat …


International Partnership Using Remotely Accessed Labs, William J. Hutzel, Rudolf Furter Jan 2005

International Partnership Using Remotely Accessed Labs, William J. Hutzel, Rudolf Furter

School of Engineering Technology Faculty Publications

An international project between the Mechanical Engineering Technology Department at Purdue University and the HVAC Engineering Department at HTA Lucerne (Switzerland) is testing the limits of the remote access concept by creating a laboratory network that is separated by thousands of miles. Using web-enabled HVAC equipment, U.S. students are determining the performance and return on investment for a heat recovery system that is physically located in Switzerland. The converse is also true, Swiss students have access to a variety of equipment located in the U.S. This remote access project is a good example of a sustainable partnership that adds an …


Low Reynolds Number Flow Through Nozzle-Diffuser Elements In Valveless Micropumps, Vishal Singhal, Jayathi Y. Murthy, S V. Garimella Apr 2004

Low Reynolds Number Flow Through Nozzle-Diffuser Elements In Valveless Micropumps, Vishal Singhal, Jayathi Y. Murthy, S V. Garimella

CTRC Research Publications

Flow characteristics of low Reynolds number laminar flow through gradually expanding conical and planar diffusers were investigated. Such diffusers are used in valveless micropumps to effect flow rectification and thus lead to pumping action in one preferential direction. Four different types of diffuser flows are considered: fully developed and thin inlet boundary layer flows through conical and planar diffusers. The results from the numerical analysis have been quantified in terms of pressure loss coefficient. The variation of pressure loss coefficient with diffuser angle is presented for Reynolds numbers of 200, 500 and 1000. The pressure loss coefficients have been used …


Remotely Accessible Solar Energy Laboratory For High School Students, William J. Hutzel, David Goodman Jan 2004

Remotely Accessible Solar Energy Laboratory For High School Students, William J. Hutzel, David Goodman

School of Engineering Technology Faculty Publications

A remotely accessible solar energy laboratory has been developed for real-time experimentation using solar heating and photovoltaic equipment that is physically located at Purdue University. Indiana high school students are the first customers for this on-line resource. In addition to sensor data, the web-based laboratory includes lesson plans, tutorials, assessment questions, and a feedback utility. This project is helping science teachers meet new state science standards from the Indiana Department of Education, which call for hands-on laboratory activities and real time data analysis. Remotely accessed labs are becoming popular because they offer the opportunity for large numbers of students to …


Optimization Of Thermal Interface Materials For Electronics Cooling Applications, Vishal Singhal, Thomas Siegmund, Suresh V. Garimella Jan 2004

Optimization Of Thermal Interface Materials For Electronics Cooling Applications, Vishal Singhal, Thomas Siegmund, Suresh V. Garimella

School of Mechanical Engineering Faculty Publications

Thermal interface materials (TIMs) are used in electronics cooling applications to decrease the thermal contact resistance between surfaces in contact. A methodology to determine the optimal volume fraction of filler particles in TIMs for minimizing the thermal contact resistance is presented. The method uses finite element analysis to solve the coupled thermo-mechanical problem. It is shown that there exists an optimal filler volume fraction which depends not only on the distribution of the filler particles in a TIM but also on the thickness of the TIM layer, the contact pressure and the shape and the size of the filler particles. …


A Comparative Analysis Of Studies On Heat Transfer And Fluid Flow In Microchannels, Choondal B. Sobhan, Suresh V. Garimella Apr 2001

A Comparative Analysis Of Studies On Heat Transfer And Fluid Flow In Microchannels, Choondal B. Sobhan, Suresh V. Garimella

CTRC Research Publications

The extremely high rates of heat transfer obtained by employing microchannels makes them an attractive alternative to conventional methods of heat dissipation, especially in applications related to the cooling of microelectronics. A compilation and analysis of the results from investigations on fluid flow and heat transfer in micro- and mini-channels and microtubes in the literature is presented in this review, with a special emphasis on quantitative experimental results and theoretical predictions. Anomalies and deviations from the behavior expected for conventional channels, both in terms of the frictional and heat transfer characteristics, are discussed.


An Interdisciplinary Solar Energy Project, William J. Hutzel Jan 1996

An Interdisciplinary Solar Energy Project, William J. Hutzel

School of Engineering Technology Faculty Publications

An HVAC course, previously offered to students in Mechanical Engineering Technology (MET), has been re-structured to include students in Building Construction Management (BCM). A large project is always an integral part of this course, creating a unique opportunity for collaboration between two distinctly different groups of Technology students. This cooperation is particularly beneficial because MET and BCM graduates frequently cross paths during their professional careers. Many MET graduates operate and service heating, ventilating, and air conditioning equipment that was originally specified and installed by BCM graduates. This paper discusses and evaluates student interactions during a solar …


Turbomachine Stability And Forced Response Prediction, Leland Bert Clark Dec 1992

Turbomachine Stability And Forced Response Prediction, Leland Bert Clark

Open Access Theses

A mathematical model is developed and utilized to analyze turbomachine cascade flutter and forced response. The flutter boundary, defined as the largest value of reduced frequency at which flutter occurs for a given cascade, was evaluated for single degree of freedom torsional oscillation as well as coupled bending and torsional oscillations. The maximum amplitude of forced response in bending and torsion was also considered. The unsteady aerodynamic lift and moment coefficients were determined from unsteady aerodynamic flow models for subsonic flow, supersonic flow with a subsonic axial component and supersonic axial flow. The effect of changing the Mach number, stagger …


Experimental And Theoretical Studies On Design Calculations For Latent Heat Storage, Dieter Lindemann Jan 1987

Experimental And Theoretical Studies On Design Calculations For Latent Heat Storage, Dieter Lindemann

Open Access Theses

Research was conducted to obtain design data of latent heat-of-fusion thermal energy storage (LHTES) devices. The devices studied utilize a porous medium (PM) to increase the effective conductivity of the storage system. Therefore the melting and freezing process is accelerated. Metal shavings and metal spheres were used as porous media and water as the phase change medium (PCM). A simple experimental method to measure the conductivity of a water-metal mixture or ice-metal mixture was applied to obtain conductivity data. These measurements can be considered fairly accurate because measured conductivity of pure water and of pure ice agreed very well with …