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Full-Text Articles in Engineering
Convective Heat Transfer Enhancement Of A Channel-Flow Using Horizontally-Oriented Piezoelectric Fans, Janak Tiwari
Convective Heat Transfer Enhancement Of A Channel-Flow Using Horizontally-Oriented Piezoelectric Fans, Janak Tiwari
Electronic Theses and Dissertations
Experimental and numerical studies were carried out to investigate the convection heat transfer enhancement of air channel flow using a piezoelectric fan, operated at 90.3 Hz. Its peak-to-peak displacement was increased up to 11.8 mm. The average velocity of channel flow was ranged up to 3 m/s, covering both laminar and turbulent flow regimes. The effects of fan location on the heat transfer performance were evaluated by changing the relative position of the fan tip to the heated surface. A maximum heat transfer enhancement of 102 % was obtained at the channel flow rate of 15 LPM. The fan was …
Resonant Ultrasound Spectroscopy: Sensitivity Analysis For Anisotropic Materials With Hexagonal Symmetry, Christopher Lee Sevigney
Resonant Ultrasound Spectroscopy: Sensitivity Analysis For Anisotropic Materials With Hexagonal Symmetry, Christopher Lee Sevigney
Electronic Theses and Dissertations
Resonance ultrasound spectroscopy (RUS) is an experimental method by which material properties are obtained by careful observation of the resonant vibrations of a meticulously crafted sample. Among the most common applications of this technique is the determination of single-crystal elasticity. Previous works have considered the reliability of elasticity information obtained via the RUS method when the material is of isotropic or cubic symmetry, and this work extends these efforts to materials with hexagonal symmetry, such as titanium di-boride. The reliability of elasticity information obtained by RUS is evaluated by Sobol Analysis and by close examination of the stiffness-frequency functionality. Findings …
Nonreciprocity Applications In Acoustics And Microfluidic Systems, Masoud Naghdi
Nonreciprocity Applications In Acoustics And Microfluidic Systems, Masoud Naghdi
Electronic Theses and Dissertations
Breaking reciprocity in linear acoustic systems and designing a novel actuator for the nonreciprocal valveless pumps are studied in this dissertation. The first part was started by deriving the acoustic governing equations in a moving wave propagation medium. It was shown thatthe Coriolis acceleration term appears ina cross-product term with the wave vector. It means the main reason for breaking reciprocity in the circular fluid flow is the Coriolis acceleration term. Finally, the governing equations were solved numerically by COMSOL Multiphysics software. Moreover, Green`s second identity was used as a complimentary method to prove breaking reciprocityin such a system with …
Convective Heat Transfer Enhancement Of A Channel-Flow Using Synthetic Jet, Pravesh Pokharel
Convective Heat Transfer Enhancement Of A Channel-Flow Using Synthetic Jet, Pravesh Pokharel
Electronic Theses and Dissertations
A transient numerical simulation was carried out using ANSYS Fluent, to investigate the convection heat transfer enhancement of the air channel flow using the synthetic jet. Keeping the dimensional parameters of the domain fixed, averaged channel flow velocity was varied up to 3m/s. The diaphragm displacement effect on synthetic jet was studied, ranging the peak-to-peak displacement value from 0.4 to 1.2mm with increment of 0.4mm. Three locations were studied to determine the best operating location of the synthetic jet. Also, frequencies were varied up to 200Hz with every 50Hz increment, from initial condition of 50Hz. It was found that the …