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You searched for +publisher:"University of Notre Dame" +contributor:("Dr. Patrick Dunn, Committee Member"). Showing records 1 – 2 of 2 total matches.

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University of Notre Dame

1. Cory Allen McElrath. Experimental Investigation of Suction on the Boundary Layer Flow Over a Rotating Disk</h1>.

Degree: MSAeroE, Aerospace and Mechanical Engineering, 2009, University of Notre Dame

An experiment was performed to study the effects of applying a uniform normal flow of suction to the surface of a flat disk rotating at constant speed. Previous research has shown that the absolute instability of Type I crossflow modes can initiate transition to turbulence in the boundary layer flow over a rotating disk. This same crossflow instability is evident in boundary layer flow over the leading edge of a swept wing. Thus, an understanding of the transition to turbulence in flow on the rotating disk can help in future research and development of laminar flow control on swept wings. For this experiment, a new disk was designed that applied suction through two different surfaces. The basic flow over this disk was documented for each surface, both with and without suction, by acquiring hot-wire velocity measurements at various radial and wall-normal positions throughout the boundary layer. These results were compared to see the effect suction had on the location of the boundary layer’s transition to turbulence, as well as the wall-normal and radial growth of velocity fluctuations caused by Type I stationary modes. The amplitudes and frequencies of these modes were also examined. Advisors/Committee Members: Dr. Flint Thomas, Committee Member, Dr. Thomas Corke, Committee Chair, Dr. Patrick Dunn, Committee Member.

Subjects/Keywords: rotating disk flow; suction; Type I crossflow instability modes

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

McElrath, C. A. (2009). Experimental Investigation of Suction on the Boundary Layer Flow Over a Rotating Disk</h1>. (Masters Thesis). University of Notre Dame. Retrieved from https://curate.nd.edu/show/zp38w952q53

Chicago Manual of Style (16th Edition):

McElrath, Cory Allen. “Experimental Investigation of Suction on the Boundary Layer Flow Over a Rotating Disk</h1>.” 2009. Masters Thesis, University of Notre Dame. Accessed January 25, 2020. https://curate.nd.edu/show/zp38w952q53.

MLA Handbook (7th Edition):

McElrath, Cory Allen. “Experimental Investigation of Suction on the Boundary Layer Flow Over a Rotating Disk</h1>.” 2009. Web. 25 Jan 2020.

Vancouver:

McElrath CA. Experimental Investigation of Suction on the Boundary Layer Flow Over a Rotating Disk</h1>. [Internet] [Masters thesis]. University of Notre Dame; 2009. [cited 2020 Jan 25]. Available from: https://curate.nd.edu/show/zp38w952q53.

Council of Science Editors:

McElrath CA. Experimental Investigation of Suction on the Boundary Layer Flow Over a Rotating Disk</h1>. [Masters Thesis]. University of Notre Dame; 2009. Available from: https://curate.nd.edu/show/zp38w952q53


University of Notre Dame

2. Rakshit Tirumala. Corona Discharges in Asymmetric Electric Fields and its Impact on Ionic Wind Generation</h1>.

Degree: PhD, Aerospace and Mechanical Engineering, 2013, University of Notre Dame

The challenge of thermal management in small form-factor electronic devices drives the development of novel technologies for heat dissipation. Ionic wind devices, which operate on the principle of electrohydrodynamic interaction, are being studied as a replacement for conventional fans because of the inherent advantages of small acoustic signature, low weight, low power consumption, and the absence of moving parts. In particular, corona discharge driven ionic winds are favored for their ease of operation in direct current (DC) mode and stability at atmospheric pressures. Miniaturization of ionic wind blowers to extremely small form factors (heights < 3 mm) is accompanied by various challenges. The operating potentials too are constrained to ~2000V to minimize safety hazards. To obtain flow rates comparable to fans under such constraints necessitates development of novel configurations and new modes of operation. This dissertation presents a multi-electrode corona discharge as a solution to the challenges arising from miniaturization of duct heights in ionic wind devices. An overview of fundamentals of corona discharges and ionic winds, and a literature survey of various ionic wind devices and numerical modeling procedures is included. Data from preliminary experiments on sub-millimeter scale coronas is presented and compared to theory to study the limiting conditions for corona formation and sustenance. Corona discharges are studied experimentally and numerically in configurations that induce asymmetric electric fields in the discharge space. Multiple collector configurations are a particular subset of these and are studied in more detail to characterize their fundamental behavior and to understand the differences from traditional discharges involving a single collecting electrode. The configurations are shown to present characteristics that are suitable for mitigating some of the problems encountered in device miniaturization. The three-electrode configurations are shown to reduce the onset potentials for device operation, increase the total current production, and present a favorable redistribution of current to the various collectors. Traditional corona modeling procedures are demonstrated to have significant shortcomings in asymmetric configurations and an alternative modeling procedure is developed for application in these conditions. The multi-electrode configurations were adapted to the development of an ionic wind blower. In a laboratory setup, these configurations are shown to improve flow rates by a factor of ~3x and reduce power consumption by up to 0.5x. A prototype fabricated within the constraints imposed by handheld electronic systems on size and operating potential is described. The performance of the prototype-installed system is compared to the baseline system for flow and acoustic characteristics and is shown to be comparable in terms of the flow rates generated and significantly better in the acoustic signature levels. Advisors/Committee Members: Dr. Hsueh-Chia Chang, Committee Member, Dr. David Go, Committee Chair, Dr. Patrick Dunn, Committee Member, Dr. Gretar Tryggvason, Committee Member.

Subjects/Keywords: corona; plasma; ionic wind; gas discharges; electrohydrodynamic

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Tirumala, R. (2013). Corona Discharges in Asymmetric Electric Fields and its Impact on Ionic Wind Generation</h1>. (Doctoral Dissertation). University of Notre Dame. Retrieved from https://curate.nd.edu/show/qv33rv06f77

Chicago Manual of Style (16th Edition):

Tirumala, Rakshit. “Corona Discharges in Asymmetric Electric Fields and its Impact on Ionic Wind Generation</h1>.” 2013. Doctoral Dissertation, University of Notre Dame. Accessed January 25, 2020. https://curate.nd.edu/show/qv33rv06f77.

MLA Handbook (7th Edition):

Tirumala, Rakshit. “Corona Discharges in Asymmetric Electric Fields and its Impact on Ionic Wind Generation</h1>.” 2013. Web. 25 Jan 2020.

Vancouver:

Tirumala R. Corona Discharges in Asymmetric Electric Fields and its Impact on Ionic Wind Generation</h1>. [Internet] [Doctoral dissertation]. University of Notre Dame; 2013. [cited 2020 Jan 25]. Available from: https://curate.nd.edu/show/qv33rv06f77.

Council of Science Editors:

Tirumala R. Corona Discharges in Asymmetric Electric Fields and its Impact on Ionic Wind Generation</h1>. [Doctoral Dissertation]. University of Notre Dame; 2013. Available from: https://curate.nd.edu/show/qv33rv06f77

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