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Full-Text Articles in Engineering

Investigation Of Non-Conventional Bio-Derived Fuels For Hybrid Rocket Motors, Scott Grayson Putnam Aug 2007

Investigation Of Non-Conventional Bio-Derived Fuels For Hybrid Rocket Motors, Scott Grayson Putnam

Doctoral Dissertations

Non-conventional bio-derived fuels have been evaluated for use in hybrid rocket motors. Tests were conducted at combustion pressures in the range of 100 – 220 psig and thrust levels of 40 – 170 newtons. Beeswax was tested with oxygen as the oxidizer and showed a regression rate at least three times as high as traditional hybrid propellant combinations such as hydroxyl-terminated polybutadiene (HTPB) and liquid oxygen (LOX). This provides the promise of a high thrust hybrid rocket motor using a simple, single port geometry and overcomes the main weakness of traditional hybrid rocket motor propellants, which are low regression rates. …


Internet Enabled Remote Driving Of A Combat Hybrid Electric Power System For Duty Cycle Measurement, Jarrett Goodell, Marc Compere, Wilford Smith, Mark Brudnak, Mike Pozolo, Et Al. Jun 2007

Internet Enabled Remote Driving Of A Combat Hybrid Electric Power System For Duty Cycle Measurement, Jarrett Goodell, Marc Compere, Wilford Smith, Mark Brudnak, Mike Pozolo, Et Al.

Publications

This paper describes a human-in-the-loop motion-based simulator interfaced to hybrid-electric power system hardware, both of which were used to measure the duty cycle of a combat vehicle in a virtual simulation environment. The project discussed is a greatly expanded follow-on to the experiment published in [1,7]. This paper is written in the context of [1,7] and therefore highlights the enhancements. The most prominent of these enhancements is the integration (in real-time) of the Power & Energy System Integration Lab (P&E SIL) with a motion base simulator by means of a “long haul” connection over the Internet (a geographical distance of …


Optimization Of Zero Net-Mass Flow Actuators For Aero-Optics Applications, Moira L. Denatale, Jonathan M. Mihaly May 2007

Optimization Of Zero Net-Mass Flow Actuators For Aero-Optics Applications, Moira L. Denatale, Jonathan M. Mihaly

Honors Capstone Projects - All

Using experimental methods, zero net-mass flow actuators were optimized to manipulate flow around an airborne laser turret in order to reduce destructive aero-optics effects. Synthetic jets are created by 50 mm and 27 mm piezoelectric disk actuators. Our optimization process involved identifying an actuator’s cavity size, driving frequency, and amplitude to achieve the strongest, most consistent jet possible. The effects of driving a single actuator versus driving two actuators in or out of phase with one another were also investigated. An initial cavity depth was determined using the Helmholtz resonator cavity approximation which estimates the ideal cavity depth for a …


Lard Used As A Fuel For Hybrid Rocket Motors, Daniel Lee Pfeffer May 2007

Lard Used As A Fuel For Hybrid Rocket Motors, Daniel Lee Pfeffer

Masters Theses

A bio-derived fuel, lard, was successfully tested using a laboratory scale hybrid rocket motor and a static test stand at the University of Tennessee-Knoxville. The experimental setup used gaseous oxygen as the oxidizer. Twenty-three experimental tests were successfully conducted with lard and oxygen. The nine-inch fuel grains used in the current investigation produced a measured thrust ranging from 70-145 Newtons (15-33 pounds) with calculated specific impulses ranging from 122-181 seconds. All the tests conducted were intensely fuel rich, and had equivalence ratios ranging from 0.2 to 0.45. The low equivalence ratios are partially due to unburned fuel particles that exit …


Optimization Of Zero Net-Mass Flow Actuators For Aero-Optics Applications, Moira L. Denatale, Jonathan M. Mihaly May 2007

Optimization Of Zero Net-Mass Flow Actuators For Aero-Optics Applications, Moira L. Denatale, Jonathan M. Mihaly

Honors Capstone Projects - All

Using experimental methods, zero net-mass flow actuators were optimized to manipulate flow around an airborne laser turret in order to reduce destructive aero-optics effects. Synthetic jets are created by 50 mm and 27 mm piezoelectric disk actuators. Our optimization process involved identifying an actuator’s cavity size, driving frequency, and amplitude to achieve the strongest, most consistent jet possible. The effects of driving a single actuator versus driving two actuators in or out of phase with one another were also investigated. An initial cavity depth was determined using the Helmholtz resonator cavity approximation which estimates the ideal cavity depth for a …


Comparative Analysis Of A High Bypass Turbofan Using A Pulsed Detonation Combustor, Ionio Q. Andrus Mar 2007

Comparative Analysis Of A High Bypass Turbofan Using A Pulsed Detonation Combustor, Ionio Q. Andrus

Theses and Dissertations

It has been proposed that the implementation of a pulsed detonation combustor in a high-bypass turbofan engine would result in an engine that is both more efficient and more reliable. The validity of the performance claims are evaluated based on a comparison between the baseline and hybrid turbofans. The hybrid pulsed detonation engine was modeled in the Numerical Propulsion Simulation System (NPSS) and shares a common architecture with the baseline turbofan model, except that the combustor of the baseline engine is replaced with a pulsed detonation combustor. Detonation effects are calculated using a closed form solution of the Chapman-Jouguet Mach …


Experimental Investigation Of Turbojet Thrust Augmentation Using An Ejector, David A. Hoffman Mar 2007

Experimental Investigation Of Turbojet Thrust Augmentation Using An Ejector, David A. Hoffman

Theses and Dissertations

The use of computer simulation in the development of autonomously controlled unmanned combat aerial vehicles (UCAV) for wide area search and engagement applications is addressed. Computer simulation is an essential tool to analyze control algorithms designed to optimally employ multiple UCAVs in wide area search and engagement. To be representative of real world mission conditions a simulation must be able to accurately duplicate the performance of the automatic target recognition (ATR) methods that will be used to discriminate between targets and non-targets in actual combat. The objective of this research is to demonstrate a method to validate a simulation's ATR …


Characterization Of A Hall Effect Thruster Using Thermal Imaging, James W. Tomaszewski Mar 2007

Characterization Of A Hall Effect Thruster Using Thermal Imaging, James W. Tomaszewski

Theses and Dissertations

A Hall thruster uses ionized xenon as a propellant for space propulsion applications. The heat produced by thruster components and the xenon plasma transfers to space and the spacecraft, impacting thruster and spacecraft design, as well as thruster efficiency and lifetime. Therefore, thermal information was gathered and analyzed in order to better understand the thermal characteristics of an operating thruster and to provide data applicable to improving the thruster efficiency and lifetime. This paper contains analysis of thruster temperatures obtained using a commercially available FLIR A40M thermographic imager in order to characterize a Busek Inc. 200W Hall Effect Thruster operating …


Soldier/Hardware-In-The-Loop Simulation-Based Combat Vehicle Duty Cycle Measurement: Duty Cycle Experiment 2, Mark Brudnak, Mike Pozolo, Victor Paul, Syed Mohammad, Marc Compere, Et Al. Jan 2007

Soldier/Hardware-In-The-Loop Simulation-Based Combat Vehicle Duty Cycle Measurement: Duty Cycle Experiment 2, Mark Brudnak, Mike Pozolo, Victor Paul, Syed Mohammad, Marc Compere, Et Al.

Publications

This paper describes a human-in-the-loop motion-based simulator interfaced to hybrid-electric power system hardware both of which were used to measure the duty cycle of a combat vehicle in a virtual simulation environment. The project discussed is a greatly expanded follow-on to the experiment published in [1]. This paper is written in the context of [1] and therefore highlights the enhancements. The most prominent of these enhancements is the integration (in real-time) of the Power & Electric System Integration Lab (P&E SIL) with a motion base simulator by means of a “long haul” connection over the Internet (a geographical distance of …


Cool Flame Propagation Speeds, Michael R. Foster, Howard Pearlman Jan 2007

Cool Flame Propagation Speeds, Michael R. Foster, Howard Pearlman

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Cool flames are studied at reduced-gravity in a closed, unstirred, spherical reactor to minimize complexities associated with natural convection. Under such conditions, transport is controlled by diffusive fluxes and the flames are observed to propagate radially outward from the center of the reactor toward the wall. Intensified video records are obtained and analyzed to determine the flame radius as a function of time for different vessel temperatures (593–623 K) and initial pressures (55.2–81.4 kPa) using an equimolar (Ø = 5) propane-oxygen premixture. Polynomial-fits are applied to the data and differentiated to determine the cool flame propagation speeds. In nearly …