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Plasma Physics
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A whitepaper on plasma physics by Prof. Kalevi Mursula from the university of Oulu, department of physical sciences. Contains a great introduction to this exciting area and a useful list of references. In physics and chemistry, plasma is a gas in which a certain portion of the particles are ionized. The presence of a non-negligible number of charge carriers makes the plasma electrically conductive so that it responds strongly to electromagnetic fields. Plasma, therefore, has properties quite unlike those of solids, liquids, or |
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Adaptive Equalization Techniques using Recurs...
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In this project, we extend the use of methods of least squares to find a recursive algorithm solution of adaptive transversal filter. Given the LS solution at any time instant n-1, we find the solution at time n recursively using past solution and newly arrived data. This algorithm is known as Recursive Least Squares (RLS) algorithm. We show the convergence rate of RLS algorithm is faster than LMS algorithm by comparing the learning curves of two algorithms for specified channel response. |
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Sustainable Energy Production and Utilization...
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A comprehensive development plan has been generated for creating a sustainable community in a remote location as part of a graduate research project. Southeast Tucson, in the state of Arizona, is the region of interest. The community is designed using the Leadership in Energy and Environmental Design (LEED) for Neighborhood Development standards as a guideline.
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System, developed by the U.S. Green Building Council (USGBC), provides a suite of standards for environmentally sustainable construction. Since its inception in 1998, LEED has grown to encompass more than 14,000 projects in the United States and 30 countries covering 1.062 billion square feet (99 km²) of development area.The hallmark of LEED is that it is an open and transparent process where the technical criteria proposed by the LEED committees are publicly reviewed for approval by the more than 10,000 membership organizations that currently constitute the USGBC.
Individuals recognized for their knowledge of the LEED rating system are permitted to use the LEED Accredited Professional (AP) acronym after their name, indicating they have passed the accreditation exam given by the... |
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Coefficient of Thermal Expansion and Thermal ...
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The surface temperature and heat flux measurements from the arc jet testing are used to determine the TPS material’s thermal conductivity. To further validate a TPS material a second thermal property is measured.That is the coefficient of thermal expansion (CTE).These two properties are combined with the mechanical properties of the material into a metric for the relative robustness of the material called the Thermal Shock Parameter (RT) |
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Temperature measurements during Reentry
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This experiment is aimed at simulating the re-entry conditions encountered during the actual flight in a plasma arc jet facility and investigating the temperature distribution along with the thermal expansion on the surface of a re-entry vehicle in order to study the thermal breakdown mechanisms of the carbon-carbon composite of the leading edge of the vehicle.This test facility is designed to test a suitably sized block of the Thermal Protection System (TPS) made up of carbon – carbon composite that is currently used in these vehicles and also any newly developed materials of appropriate size for evaluation as a possible replacement. The final outcome of this project is intended to be a quantitative relation that indicates the robustness of a material and thereby its ability to qualify as a material of choice for reusable re-entry vehicles. |
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Plasma Wind Tunnels
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Various plasma wind tunnels have been built for developing reusable space transportation systems and space probes entering the atmospheres of celestial bodies. All together they cover almost the whole reentry trajectory of a space craft. They generate continuous plasma flows of high specific enthalpy and velocity with thermal or magnetoplasmadynamic generators. Plasma wind tunnels are used for:(1) Development and qualification of radiation and ablative cooling materials and thermal protection systems (2) Validation of numerical codes for reentry prediction (3) Development and qualification of reentry measurement devices |
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Hydrogen sensors based on titania nano-tubes
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This article is a literature survey on the fabrication of novel H2 sensors based on titania nano-tubes prepared using anodization and annealed in an oxygen atmosphere. The as prepared nano-tubes are amorphous but they crystallize on annealing at elevated temperatures and are structurally stable (which is a requirement of any sensor) to at least 600 °C.Titania nano-tubes are grown from titanium foil (≈99.5% pure) of thickness 0.25 mm. The anodization is performed in an electrolyte medium of 0.5% hydrofluoric acid in water, using a platinum foil cathode. A well defined nano-tube architecture results, with nano-tube length of 400 nm in approximately 20 minutes.Measurement of H2 concentration is based on the increase in conductivity of the nano-tube surface in a hydrogen ambient as compared to its original conductivity, and this is quantified by ’sensitivity’ ratio, S = (R0 – Rgas)/Rgas (where R0 is the electrical resistance of the sensor before passing the gas and Rgas that after passing gas and reaching the saturation value). The sensor shows significant hydrogen sensitivity, with a three order of magnitude change in resistance as compared to its original resistance. The major process behind the interaction between the nano-tu... |
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Supersonic Nozzle design by Method of Charact...
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Using the 2D Method of Characteristics (MOC), the contour of a two dimensional minimum-length nozzle for the expansion of air to a design exit Mach number of 2 is computed and graphed. The problem is extended to include a nozzle with a finite expansion section which is a circular arc with a diameter equal to three throat heights. C++ source codes for the 2 nozzles are included. By inputting the values of gas constant, test section mach number, throat height and level of precision one can design nozzles for different working fluids at different test section mach numbers. The report was generated as a part of a graduate course on compressible aerodynamics taught that semester by Dr John D Anderson. His book entitled 'Modern Compressible Flow - with Historical perspectives' contain a good chapter on the use of the MOC in designing supersonic nozzle contours (Chapter 11 of the third edition). |
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Laminar Separation Bubble
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This essay focuses on the phenomenon of Laminar Separation Bubble observed at Low Reynolds Numbers. The effect of this bubble on the airfoil characteristics is discussed. Airfoils used at low Reynolds numbers have to be designed taking into consideration the finite space and time occupied by the bubble. Active as well as passive mechanisms to control/delay the formation of the bubble are also mentioned.
For conventional aircraft wings, whose Reynolds number exceeds a million, the flow is typically turbulent with the boundary layer able to strengthen itself by ‘mixing’. Consequently flow doesn’t separate until high angles of attack are encountered. For lower Reynolds numbers, the flow is initially laminar and is prone to separate even under mild adverse pressure gradient. Under certain flow conditions, the separated flow reattaches and forms a Laminar Separation Bubble (Fig. 1) while transitioning from laminar to turbulent state. Laminar separation bubble could modify the effective shape of the airfoil and consequently influence the aerodynamic performance, generally in a negative manner.
The need to understand low Reynolds number (104 to 106) aerodynamics is driven by variety of applicat... |
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A Technical Essay on the Gyroplane
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A study of “Gyroplane” and its historical evolution, general characteristics, flight characteristics, various designs, potential applications and aerodynamics explaining its flight is attempted. “Gyroplane” is an official term designated by the Federal Aviation Administration (FAA) describing an aircraft that gets lift from a freely turning rotary wing, or rotor blades, and which derives its thrust from an engine-driven propeller. The focus is on highlighting the differences between a Gyroplane and a conventional helicopter, relative merits and demerits and to trace the development to helicopters from autogiros. What lies ahead in the future for gyroplanes is also discussed.
Cierva thought of designing a flying machine that remains stable, safe and controllable irrespective of its forward speed. He segregated the function of lift and forward propulsion, where the former was done by a freely rotating rotor (and not wings) and latter by a conventional pusher or tractor engine.The rotor of an Autogiro (term coined and patented by Cierva) always works in a state of autorotation and a small upward flow is sufficient to rotate the disk. Thus, as long as the machine has forward motion the rotor would produce sufficient lif... |
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