1,268 research outputs found
Diffuser/ejector system for a very high vacuum environment
Turbo jet engines are used to furnish the necessary high temperature, high volume, medium pressure gas to provide a high vacuum test environment at comparatively low cost for space engines at sea level. Moreover, the invention provides a unique way by use of the variable area ratio ejectors with a pair of meshing cones are used. The outer cone is arranged to translate fore and aft, and the inner cone is interchangeable with other cones having varying angles of taper
Parametric analysis of diffuser requirements for high expansion ratio space engine
A supersonic diffuser ejector design computer program was developed. Using empirically modified one dimensional flow methods the diffuser ejector geometry is specified by the code. The design code results for calculations up to the end of the diffuser second throat were verified. Diffuser requirements for sea level testing of high expansion ratio space engines were defined. The feasibility of an ejector system using two commonly available turbojet engines feeding two variable area ratio ejectors was demonstrated
Integration and software for thermal test of heat rate sensors
A minicomputer controlled radiant test facility is described which was developed and calibrated in an effort to verify analytical thermal models of instrumentation islands installed aboard the space shuttle external tank to measure thermal flight parameters during ascent. Software was provided for the facility as well as for development tests on the SRB actuator tail stock. Additional testing was conducted with the test facility to determine the temperature and heat flux rate and loads required to effect a change of color in the ET tank external paint. This requirement resulted from the review of photographs taken of the ET at separation from the orbiter which showed that 75% of the external tank paint coating had not changed color from its original white color. The paint on the remaining 25% of the tank was either brown or black, indicating that it had degraded due to heating or that the spray on form insulation had receded in these areas. The operational capability of the facility as well as the various tests which were conducted and their results are discussed
Preliminary engineering report for design of a subscale ejector/diffuser system for high expansion ratio space engine testing
The design of a subscale jet engine driven ejector/diffuser system is examined. Analytical results and preliminary design drawings and plans are included. Previously developed performance prediction techniques are verified. A safety analysis is performed to determine the mechanism for detonation suppression
Dynamics of the Tippe Top -- properties of numerical solutions versus the dynamical equations
We study the relationship between numerical solutions for inverting Tippe Top
and the structure of the dynamical equations. The numerical solutions confirm
oscillatory behaviour of the inclination angle for the symmetry
axis of the Tippe Top. They also reveal further fine features of the dynamics
of inverting solutions defining the time of inversion. These features are
partially understood on the basis of the underlying dynamical equations
Nonlinear Faraday Rotation and Superposition-State Detection in Cold Atoms
We report on the first observation of nonlinear Faraday rotation with cold
atoms at a temperature of ~100 uK. The observed nonlinear rotation of the light
polarization plane is up to 0.1 rad over the 1 mm size atomic cloud in
approximately 10 mG magnetic field. The nonlinearity of rotation results from
long-lived coherence of ground-state Zeeman sublevels created by a
near-resonant light. The method allows for creation, detection and control of
atomic superposition states. It also allows applications for precision
magnetometry with high spatial and temporal resolution.Comment: 5 pages, 6 figure
MARKETING OF COTTON FIBER IN THE PRESENCE OF YIELD AND PRICE RISK
An expected utility model and a chance constrained linear programming model were used to analyze four marketing strategies and seven crop insurance alternatives in cotton marketing in Georgia. The results obtained suggest that the existing marketing tools and insurance alternatives can be used successfully as a substitute for government support.Demand and Price Analysis, Marketing, Risk and Uncertainty,
Study of high altitude plume impingement
Computer program has been developed as analytical tool to predict severity of effects of exhaust of rocket engines on adjacent spacecraft surfaces. Program computes forces, moments, pressures, and heating rates on surfaces immersed in or subjected to exhaust plume environments. Predictions will be useful in design of systems where such problems are anticipated
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