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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

A study of alternate fingerings and harmonics on the flute, oboe, and clarinet with implications for their practical use in solving problems in intonation and flexibility.

Luoma, Matt Jonas. January 1946 (has links)
Thesis (M.A.)--Ohio State University, 1946. / Includes bibliographical references. Available online via OhioLINK's ETD Center
62

Wind energy analysis system

Koegelenberg, Johan 30 September 2014 (has links)
M.Ing. (Electrical & Electronic Engineering) / One of the most important steps to be taken before a site is to be selected for the extraction of wind energy is the analysis of the energy within the wind on that particular site. No wind energy analysis system exists for the measurement and analysis of wind power. This dissertation documents the design and development of a Wind Energy Analysis System (WEAS). Using a micro-controller based design in conjunction with sensors, WEAS measure, calculate and store the wind energy measurements relative to time. Success of the project is demonstrated by a working prototype.
63

Dynamic compensation for performance characteristic differences of wind generator coupled pumps

Swanepoel, Pieter Frederick Renier January 2000 (has links)
The lack of services such as electricity in the rural areas of South Africa has given rise to the use of pump water and the windmills. The ones in use currently are maintenance intensive. There is a corrosive element in water and this sometimes requires plastic or other non-corrosive materials to be used for pump components and pipes. Solar panels are expensive and have low efficiencies. Alternative energy systems such as diesel engine driven- mono pumps or -turbines or windmills are costly, which means that the overall efficiency must be maximized to reduce these costs.
64

A theory for wind tunnel wall corrections

Williams, C. D. (Christopher Dwight) January 1973 (has links)
Wall correction theories for two-dimensional airfoils in wind tunnels with partly open walls are examined. Conventional wall correction theories are linearized theories, valid only for small thin models of slight camber at low angles of attack. Such theories are shown to be useless for the prediction of the required wall corrections for large models, models at high angles of attack, or models developing high lift. An exact numerical theory is presented in which it is not necessary to make these assumptions. The airfoil and any solid wall sections are represented by surface source and vortex singularities as in the method of A.M.O. Smith. Aerodynamic lift is determined by numerical integration of the calculated pressure distributions around the airfoil contour. The theory indicates that certain wall configurations will require small or negligible wall corrections for tests on lifting airfoils. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
65

An investigation of the theoretical and experimental aerodynamic characteristics of a low-correction wind tunnel wall configuration for airfoil testing

Malek, Ahmed Fouad January 1983 (has links)
This thesis deals with a new approach to reduce wall corrections in high-lift airfoil testing, by employing two similar non-uniform transversely slotted walls. The solid elements of the slotted wall are symmetrical airfoils at zero incidence, and the spaces between the slats are non-uniform, increasing linearly towards the rear. This wall configuration provides the flow conditions close to the free air test environment which lead to negligible or small wall corrections. The theory uses the potential flow surface vortex-element method, with "Full Load" Kutta Conditions satisfied on the test airfoil and wall slats. This method is very well supported by physical evidence and it is simple to use. The surface velocities can be calculated directly and the aerodynamic lift and pitching moment are determined by numerical integration of the calculated pressure distributions around the airfoil contour. This method can be developed to include a simulation of the flow in the plenum chambers in the analysis. Also, the performance of this new wall configuration was examined experimentally. Two different sizes of NACA-0015 airfoil were tested in the existing low speed wind tunnel after modifying both the configuration of the side walls and the test section to accommodate the new test. Pressure distributions about the test airfoils were measured using pressure taps around their contours. Also the lifts and the pitching moments were obtained by integrating the measured surface pressures. The experimental, results show that the use of the new wall configuration with AOAR = 59% would produce wind tunnel test data very close to the free air values. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
66

Comparison of algorithms for determination of solar wind regimes

Neugebauer, Marcia, Reisenfeld, Daniel, Richardson, Ian G. 09 1900 (has links)
This study compares the designation of different solar wind flow regimes (transient, coronal hole, and streamer belt) according to two algorithms derived from observations by the Solar Wind Ion Composition Spectrometer, the Solar Wind Electron Proton Alpha Monitor, and the Magnetometer on the ACE spacecraft, with a similar regime determination performed on board the Genesis spacecraft. The comparison is made for the interval from late 2001 to early 2004 when Genesis was collecting solar wind ions for return to Earth. The agreement between hourly regime assignments from any pair of algorithms was less than two thirds, while the simultaneous agreement between all three algorithms was only 49%. When the results of the algorithms were compared to a catalog of interplanetary coronal mass ejection events, it was found that almost all the events in the catalog were confirmed by the spacecraft algorithms. On the other hand, many short transient events, lasting 1 to 13h, that were unanimously selected as transient like by the algorithms, were not included in the catalog.
67

Geostrophic and observed wind comparisons

Unknown Date (has links)
"Based upon the premise that a single wind near the midpoint of a triangular area represents the mean wind of the area, a statistical study was made of the relationship between observed and computed geostrophic winds. Comparisons were made of observed and computed winds for five triangles at the 700, 500, and 300-mb levels. After comparing a single wind of a triangle with a geostrophic wind and the vector mean of the three observed winds at the vertices of this triangle, the results indicated that the central observed wind may deviate widely from the geostrophic wind and from the average observed wind of the triangle"--Introduction. / "January, 1955." / Typescript. / "Submitted to the Graduate Council of Florida State University in partial fulfillment of the requirements for the degree of Master of Science." / Includes bibliographical references (leaf 23).
68

Vertical axis wind turbine using sails

Ngabo, T. M., 1948- January 1978 (has links)
No description available.
69

Potential for wind power development in Southern Quebec.

Kadivar, Mohammad Saeed. January 1970 (has links)
No description available.
70

Investigation of the effects of increased sophistication of simulation of the atmospheric wind in wind tunnels

Cusick, A. H. January 1988 (has links)
No description available.

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