Apollo Lightcraft Project

The ultimate goal for this NASA/USRA-sponsored Apollo Lightcraft Project is to develop a revolutionary manned launch vehicle technology which can potentially reduce payload transport costs by a factor of 1000 below the Space Shuttle Orbiter. The Rensselaer design team proposes to utilize advanced, highly energetic, beamed-energy sources (laser, microwave) and innovative combined-cycle (airbreathing/rocket) engines to accomplish this goal. The research effort focuses on the concept of a 100 MW-class, laser-boosted Lightcraft Technology Demonstrator (LTD) drone. The preliminary conceptual design of this 1.4 meter diameter microspacecraft involved an analytical performance analysis of the transatmospheric engine in its two modes of operation (including an assessment of propellant and tankage requirements), and a detailed design of internal structure and external aeroshell configuration. The central theme of this advanced propulsion research was to pick a known excellent working fluid (i.e., air or LN sub 2), and then to design a combined-cycle engine concept around it. Also, a structural vibration analysis was performed on the annular shroud pulsejet engine. Finally, the sensor satellite mission was examined to identify the requisite subsystem hardware: e.g., electrical power supply, optics and sensors, communications and attitude control systems

Heat Exchanger Design and Testing for a 6-Inch Rotating Detonation Engine

This thesis explains the design and testing of a water-cooled rotating detonation engine (RDE) run on hydrogen and air. The change in water temperature as it cooled the engine was used to find the steady heat rate into the containing walls of the detonation channel. The engine successfully ran four times for 20 seconds each. The steady-state heat rate was measured to be 2.5% of the propellant lower heating value (LHV) into the outer wall and 7.1% of LHV into the inner wall. Additionally, a quick-response resistance temperature detector (RTD) was used in an uncooled RDE of similar dimension to the cooled RDE to estimate the transient heat flux profile in the detonation channel. The average heat flux into the outer wall near the base of the channel was measured to be four times greater than the average heat flux over the entire cooled wall at steady-state, indicating the heat flux decreases significantly with axial distance. In addition, the large difference in heat absorption between the inner and outer cooled walls indicates that the heat flux into the inner wall is greater than that into the outer wall

Air Force Institute of Technology Research Report 2010

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physic

Prevention, Detection, and Suppression of Hydrogen Explosions in Aerospace Vehicles

Prevention, detection, and suppression of hydrogen explosions in aerospace vehicle

Publications of the Jet Propulsion Laboratory July 1965 through July 1966

Bibliography on Jet Propulsion Laboratory technical reports and memorandums, space programs summary, astronautics information, and literature searche

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

NAS technical summaries. Numerical aerodynamic simulation program, March 1992 - February 1993

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1992-93 operational year concluded with 399 high-speed processor projects and 91 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year

Optical Breakdown in Gases Induced by High-power IR CO2 Laser Pulses

This chapter reviews some fundamentals of laser-induced breakdown spectroscopy (LIBS) and describes some experimental studies developed in our laboratory on gases such as nitrogen, oxygen and air. LIBS of these gases at different pressures, in the spectral range ultraviolet-visible-near infrared (UV-Vis-NIR), was excited by using a high-power transverse excitation atmospheric (TEA) CO2 laser (¿=9.621 or 10.591 ¿m; tFWHM=64 ns; and different laser power densities). The spectra of the generated plasmas are dominated by emission of strong atomic, ionic species and molecular bands. Excitation temperatures are estimated from the intensities of atomic and ionic lines. Electron number densities are deduced from the Stark broadening of several ionic lines. The characteristics of the spectral emission intensities from different species have been investigated as functions of the gas pressure and laser irradiance. Optical breakdown threshold intensities in different gases have been experimentally measured. The physical processes leading to laser-induced breakdown of gases have been analyzed. Plasma characteristics of LIBS in air are examined in detail on the emission lines of N+, O+ and C by using time-resolved optical-emission spectroscopy (OES) technique. The results show a faster decay of continuum and ionic spectral species than of neutral atomic and molecular ones. The velocity and kinetic energy distributions for the different species are obtained from time-of-flight (TOF) OES measurements. Excitation temperatures and electron densities in the laser-induced plasma are estimated from the analysis of spectral data at various times from the laser pulse incidence. Temporal evolution of electron density has been used for the estimation of the three-body recombination rate constant.Peer Reviewe

Laser Induced Incandescence and Laser Induced Breakdown Spectroscopy based Sensor Development

In this doctoral dissertation, two laser-based sensors were evaluated for different applications. Laser Induced Incandescence (LII) is a technique which can provide nonintrusive quantitative measurement of soot and it provides a unique diagnostic tool to characterize engine performance. Since LII is linearly proportional to the soot volume fraction, it can provide in situ, real time measurement of soot volume fraction with high temporal and spatial resolution. LII has the capability to characterize soot formation during combustion. The soot volume fraction from both flames and a soot generator was investigated with LII. The effects of experimental parameters, such as laser fluence, gate delay, gate width and various laser beam focusing, on LII signal was studied. Laser Induced Breakdown Spectroscopy (LIBS), a diagnostic tool for in situ elemental analysis, has been evaluated for on-line, simultaneous, multi-species impurity monitoring in hydrogen. LIBS spectra with different impurity levels of nitrogen, argon, and oxygen were recorded and the intensity of the spectral lines of Ar, O, N, and H observed were used to form calibration plots for impurities in hydrogen measurements. An ungated detection method for LIBS has been developed and applied to equivalence ratio measurements of CH4/air and biofuel/air. LIBS has also been used to quantitatively analyze the composition of a slurry sample. The quenching effect of water in slurry samples causes low LIBS signal quality with poor sensitivity. Univariate and multivariate calibration was performed on LIBS spectra of dried slurry samples for elemental analysis of Mg, Si and Fe. Calibration results show that the dried slurry samples give good correlation between spectral intensity and elemental concentration