Solar array flight dynamic experiment

The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures' dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-41D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability

Solar array flight dynamic experiment

The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-31D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability

A review of internal combustion engine combustion chamber process studies at NASA Lewis Research Center

The performance of internal combustion stratified-charge engines is highly dependent on the in-cylinder fuel-air mixing processes occurring in these engines. Current research concerning the in-cylinder airflow characteristics of rotary and piston engines is presented. Results showing the output of multidimensional models, laser velocimetry measurements and the application of a holographic optical element are described. Models which simulate the four-stroke cycle and seal dynamics of rotary engines are also discussed

An Economic Analysis of Fluid Milk Processing in Alaska

Alaskan fluid milk is processed for market by a two-firm industry. In Delta Junction, the Northern Lights Dairy obtains milk from two producers and services an Interior market from Delta to Fairbanks. In Anchorage , Matanuska Maid (M-M) obtains milk from II producers and markets its products largely in southcentral Alaska and , to a less extent, in Fairbanks. Direct competition between the two is minimal. The principal source of competition is preprocessed fluid milk shipped in from Puget Sound

An investigation into the probabilistic combination of quasi-static and random accelerations

The development of design load factors are investigated for aerospace and aircraft components and experiment support structures, which are subject to a simultaneous vehicle dynamic vibration and acoustically generated random vibration. The characteristics of the combined acceleration probability density function is determined, and an appropriate percentile level for the combined acceleration is selected. This mechanism is developed and graphical data is provided to select combined accelerations for most popular percentile levels

A Survey of Shock and Vibration Environments in the Four Major Modes of Transportation

No abstract availabl

Regressed relations for forced convection heat transfer in a direct injection stratified charge rotary engine

Currently, the heat transfer equation used in the rotary combustion engine (RCE) simulation model is taken from piston engine studies. These relations have been empirically developed by the experimental input coming from piston engines whose geometry differs considerably from that of the RCE. The objective of this work was to derive equations to estimate heat transfer coefficients in the combustion chamber of an RCE. This was accomplished by making detailed temperature and pressure measurements in a direct injection stratified charge (DISC) RCE under a range of conditions. For each specific measurement point, the local gas velocity was assumed equal to the local rotor tip speed. Local physical properties of the fluids were then calculated. Two types of correlation equations were derived and are described in this paper. The first correlation expresses the Nusselt number as a function of the Prandtl number, Reynolds number, and characteristic temperature ratio; the second correlation expresses the forced convection heat transfer coefficient as a function of fluid temperature, pressure and velocity

Comparative Analysis of Definitions of Social Group

A set of categories for the analysis of definitions of social group and a set of categories developed by the author were compared to determine which set had the greater parsimony and utility. The sets of categories were compared in order to specify the areas of agreement and disagreement. The sets of categories were applied to a sample of early European and American sociologists\u27 conceptions of social group and a sample of 22 introductory sociology text definitions. Smh\u27s inclusion of non-human individuals, one-way communication, and noncontemporaneous group members in his set of categories was unsupported by the samples of definitions. The combination of Smith\u27s categories, shared goal dispositions and \u27norms regarding means, into the author\u27s category, shared goal dispositions, and Smith\u27s categories, role differentiation and intergroup relations and group representative roles, into the author\u27s category, role differentiation, received some support from the samples of definitions. Smith\u27s categories, mutual need satisfaction, face-to-face interaction, and socioemotional relations among group members were not cited in any of the samples. The author\u27s category, social structure, received some support from the samples of definitions