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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Algorithm, based on the Borel method of summing divergent sequences, is used for smoothing noisy data where knowledge of frequency content is not required. Technique's effectiveness is demonstrated by a series of graphs.
Static rocket thrust chamber simulator for cylindrical cold flow-type apparatus design
Slosh damping method for liquid rocket propellant tanks
Optimal control of space shuttle vehicles by using gust alleviators to counteract atmospheric disturbances
Device for adding water to high velocity exhaust jets to reduce velocity, noise, and temperature
Human metabolic study showing effect of yeast RNA and allopurinol on serum and urinary uric acid formation
Thin shell design for minimum bending stresses and transverse shear for composite materials with low interlaminar shear strength
Low noise turbofan engine without aerodynamic blade loading
Potential value of loads alleviation control for space shuttles for rigid body design load reduction techniques
Analysis of aluminum and nonmetallic baffles for use with oxygen containers to prevent sloshing
Addition of boron compound to lower burning rate of solid propellant binder is reported. Chemical reactions involved in propellant binder modification are described. Advantages of method for lowering burning rate are analyzed.
Nonarray absorbing devices were investigated for use in rocket thrust chambers as instability suppressors. A theory for designing absorbing devices suitable for rocket application is derived, and a nonarray computer program is developed. The experimental program used to verify the theory is discussed. It is concluded that individual acoustical devices can be designed for maximum energy absorption, and it is recommended that single resonators be designed so that the ratio of the aperture diameter to the product of the quarter-wave length and cavity backing depth is less than one.
The measurement of wind tunnel background pressure fluctuations in a Ludwig Tube is discussed. The measurements are to provide improved unsteady aerodynamic data for the design of aeronautical vehicles. The preliminary results of the facility calibration are presented. The noise generation mechanisms are discussed. The ability of conducting short duration acoustic tests is demonstrated, and amplitude and frequency data are given. Techniques of noise reduction are included.
A conceptual design of an afterburner system for turbojet engines which may reduce the jet exhaust noise by approximately 10 decibels is presented in this report. The proposed system consists of an array of swirl-can combustors and jet dividing nozzle tubes. The nozzle tubes translate axially upstream of the swirl cans when not in use. Results of preliminary design calculations and photographs of a kinematic model as applied to a hypothetical turbojet engine are presented.
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Analyzer operates with broadband light from blackbody infrared source. Light is passed sequentially through two gas-filled chambers to suitable infrared detector while pressures in gas-filled chambers are modulated in sinusoidal manner. Because pressure of infrared-absorbing gases in chambers is modulated, amount of light absorbed by gases is also modulated.
Properly tuned Helmholtz resonator damping devices are an effective method for eliminating high frequency combustion instability in rocket engine thrust chambers. A program was implemented with the objective of extending Helmholtz resonator theory to thrust chamber conditions to establish a standard design procedure. By using systematic cold-flow testing and hot firings, empirical design equations were formulated. An effort is currently underway to extend the design theory to other types of acoustical damping devices such as quarter-wave tubes and slots.
A scheme which permits the ends (near the anode seals) as well as the bottom and sides of an X-ray astronomy proportional counter to be protected by anticoincidence guard counters is described. A rocket-borne test showed that the non-X-ray background is reduced by an additional factor of about 30 when the end guard counter feature is added.