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AII1349 H alpha flares occurring in 1980 which have known start, maximum brightness, and end times, latitudes, and associated importance and X-ray classes were used to perform a statistical study of flare rise time, decay time, duration, latitude, importance (areal and relative intensity), and X-ray class. Frequency distributions of these parameters are tabulated and plotted.
The overall and blade-element performance of a transonic compressor stage is presented over the stable operating range for speeds from 50 to 100 percent of design. The stage was designed for a pressure ratio of 2.05 at a flow of 20.2 kg/sec and a tip speed of 455 m/sec. At design speed the rotor and stage achieved peak efficiencies of 0.849 and 0.831, respectively, at the minimum flow condition. The stage stall point occurred at a flow higher than the design flow.
Techniques for the computation of heat transfer and associated phenomena in complex structures are examined with an emphasis on reentry flight vehicle structures. Analysis methods, computer programs, thermal analysis of large space structures and high speed vehicles, and the impact of computer systems are addressed.
The status of an effort to increase the efficiency of calculating transient temperature fields in complex aerospace vehicle structures is described. The advantages and disadvantages of explicit and implicit algorithms are discussed. A promising set of implicit algorithms with variable time steps, known as the GEAR package is described. Four test problems, used for evaluating and comparing various algorithms, were selected and finite element models of the configurations are described. These problems include a space shuttle frame component, an insulated cylinder, a metallic panel for a thermal protection system, and a model of the space shuttle orbiter wing. Results generally indicate a preference for implicit oer explicit algorithms for solution of transient structural heat transfer problems when the governing equations are stiff.
It is noted that the application of finite element or finite difference techniques to the solution of transient heat transfer problems in structures often results in a stiff system of ordinary differential equations. Such systems are usually handled most efficiently by implicit integration techniques which require the solution of large and sparse systems of algebraic equations. The assembly and solution of these systems using the incomplete Cholesky conjugate gradient algorithm is examined. Several examples are used to demonstrate the advantage of the algorithm over other techniques.
Some recently achieved results concerning the technological fundamentals of slurry sawing are presented. The specific material removal process and the related kinematic and geometric contact conditions between workpiece and saw blade are described. The result of a functional description of the slurry sawing process is presented, expressing the main process criteria, such as infeed per stroke, specific removal rate, specific tool wear, and vertical stroke intensity, in terms of the dominating process parameters, such as stroke length, width of workpiece, stroke frequency, specific cutting force and slurry specification.
Based on 1349 hydrogen alpha flares with X-ray counterparts, an investigation into the relationship between the rise time, decay time, duration, latitude, hydrogen alpha importance, and X-ray class with 2800 MHz radio emission (F2800) was accomplished. An important finding is that during 1980 both the number of hydrogen alpha importance class 1 and number of X-ray class M (and M+X) flares appeared to be rather strongly related to F2800, in a positive sense; i.e., number of class 1 and class M events increased as F2800 increased.
Theory of the dynamic nature of solar flares, eruptive prominences, and coronal transients is surveyed. Two types of flare are considered: compact eruptions (small flares) which are probably loops, and large eruptions of double filament flares. The physical sense of this classification is justified, using solar observations. Even leaving the question unanswered of whether a coronal transient is a loop of ejected matter or a shock wave, the important, perhaps fundamental, role of mass motion in flare physics is evidenced.
Various three dimensional inlet models were calculated based on the potential flow model. Results are presented in the forms of surface static pressure, flow angularity, surface flow pattern, and inlet flow field. It is indicated that the extension of the lower lip can reduce the adverse pressure gradient and increase the flow separation bound.
Photogrammetric control generation is discussed. Techniques in remote sensing data reduction are described. Emphasis is placed on methods of rectification of aerial photography and frame photography. Examples of multispectral band scanner data that were processed are presented.
A procedure for sizing an airframe for flutter-free performance is demonstrated on a large, flexible supersonic transport aircraft. The procedure is based on using a two-level reduced basis or modal technique for reducing the computational cost of performing the repetitive flutter analyses. The supersonic transport aircraft exhibits complex dynamic behavior, has a well-known flutter problem and requires a large finite-element model to predict the vibratory and flutter response. Flutter-free designs are produced with small mass increases relative to the wing structural weight and aircraft payload. In view of the ability of the resizing procedure to handle this supersonic transport configuration, it seems likely that the method could be used for many other aircraft.
The status of an effort to increase the efficiency of calculating transient temperature fields in complex aerospace vehicle structures is described. The advantages and disadvantages of explicit and implicit algorithms are discussed. A promising set of implicit algorithms with variable time steps, known as the GEAR package is described. Four test problems, used for evaluating and comparing various algorithms, have been selected and finite-element models of the configurations are described. These problems include a Space Shuttle frame component, an insulated cylinder, a metallic panel for a thermal protection system, and a model of the Space Shuttle Orbiter wing. Results generally indicate a preference for implicit over explicit algorithms for solution of transient structural heat transfer problems when the governing equations are 'stiff' (typical of many practical problems such as insulated metal structures).
Spacecraft that are partially rigid and partially flexible may be dynamically modeled in terms of either 'constrained' modes of vibration, for which the rigid part is held motionless, or the 'unconstrained' modes of the whole vehicle. A model 'completeness index' is defined for each expansion and used as a truncation criterion. Using as an example a large flexible platform with a rigid body at the center, it is shown that as the rigid portion of the vehicle becomes very small, a great many constrained modes are needed to achieve satisfactory model completeness. Otherwise, one finds an erroneous distribution of angular momentum among the modes. It is also shown that the importance of unconstrained modes is not necessarily ordered by frequency.
Halogens, P, U and Na are reported in anorthositic and basaltic clasts and matrix from rusty rock 66095. Large fractions of Cl and Br associated with the separated phases from 66095 are soluble in H2O. Up to two orders of magnitude variation in concentrations of these elements in the breccia components and varying H2O-soluble Cl/Br ratios indicate different sources of volatiles. An approximately constant ratio of the H2O- to 0.1 M HNO3-soluble Br in the various components suggests no appreciable alteration in the original distributions of this element in the breccia forming processes. Up to 50% or more of the phosphorus and of the non-H2O-soluble Cl was dissolved from most of the breccia components by 0.1 M HNO3. Clast and matrix residues from the leaching steps contain, in most cases, the Cl/P2O5 ratio found in 66095 whole rock and in a number of other Apollo 16 samples. Evidence that phosphates are the major P-phases in the breccia is based on the 0.1 M acid solubility of Cl and P in the matrix sample and on elemental concentrations which are consistent with those of KREEP.
(Previously announced in STAR as N82-15198)
A rat suspension model to simulate the effects of weightlessness was developed by U.S. researchers coincident with U.S. involvement in Cosmos-satellite studies. This paper presents some preliminary data dealing with weight gain, food consumption, and bone formation in the rat model as compared with data from the Cosmos 782 and 936 experiments. It is shown that significant changes in bone formation rates may occur during a space flight lasting only five days.
Detached close binary systems define the main sequence band satisfactorily, but very little is known about the masses of giants and supergiants. High-dispersion IUE observations promise an improvement, since blue companions are now frequently found to late-type supergiants. The interesting cases of Mu Sagittarii and in particular of Epsilon Aurigae are discussed in more detail. The barium star abundance anomaly appears now to be due to mass transfer in interacting systems. The symbiotic stars are another type of binary systems containing late-type giants; several possible models for the hotter star and for the type of interaction are discussed. The W Serpentis stars appear to be Algols in the rapid phase of mass transfer, but a possible link relating them to the symbiotics is also indicated. Evidence of hot circumstellar plasmas has now been found in several ordinary Algols; there may exist a smooth transition between very quiescent Algols and the W Serpentis stars. Bet2 Lyrae is discussed in the light of new spectrophotometric results.
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