Tests of a single-tube-in-shell water boiler with helical-wire insert, inlet nozzle, and two different inlet-region plugs
Steady-state pressure drop and heat transfer data for single-tube-in-shell water boiler
Sekas, N. J.↗
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Results for “HELICS”
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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Experimental study of blade-type helical flow inducers in a 5/8-inch electrically heated boiler tube
Effects of blade-type flow swirlers on maximum exit quality of 5/8-inch boiler tubes
Sekas, N. J.↗
The bending of space curves into piecewise helical curves
Regular C cubed space curve bending in Euclidean 3-space into piecewise helix, considering torsion and curvature
Sloss, J. M.↗
The Goddard helical tape recorder
A spacecraft recorder was developed with the objective of functioning continuously for 5 years. The resulting design employed a metallic tape wound in a 200-turn helix. A direct drive, brushless dc torquer and servo speed control drove the recorder at 3 rpm for recording and 54 rpm for playback.
Martin, F. T.↗
Sound interaction with a helical flow contained in an annular duct with radial gradients of flow, density and temperature.
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Kapur, A.↗
Magnetoresistance and field-induced phase transitions in the helical antiferromagnetic state of dysprosium
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Akhavan, M.↗
Electron motion in a helically perturbed magnetic field
Exact solutions have been obtained for the equations of an electron subjected to a transverse rotating magnetic field superimposed on a homogeneous axial magnetic field. The solutions show that complete transfer of the axial energy into transverse energy is possible for a range of values of the injection velocity and the transverse magnetic field.
Singh, A.↗
Dynamic Capacity and Surface Fatigue Life for Spur and Helical Gears
A mathematical model for surface fatigue life of gear, pinion, or entire meshing gear train is given. The theory is based on a previous statistical approach for rolling-element bearings. Equations are presented which give the dynamic capacity of the gear set. The dynamic capacity is the transmitted tangential load which gives a 90 percent probability of survival of the gear set for one million pinion revolutions. The analytical results are compared with test data for a set of AISI 9310 spur gears operating at a maximum Hertz stress of 1.71 billion N/sq m and 10,000 rpm. The theoretical life predictions are shown to be good when material constants obtained from rolling-element bearing tests were used in the gear life model.
Coy, J. J.↗
Helical channel multiplier package design for space instrumentation
The package considered is intended for the channel electron multiplier (CEM) detectors which are to be used for the extreme ultraviolet telescope and helium glow detector instruments of the Apollo-Soyuz test project. In the package design selected, the cone of the CEM is supported at the front end by a silicone rubber ring which is molded in place and self-bonded to both the cone and the housing wall. The helix is supported and insulated from the housing by a fiber glass sleeve which is bonded to the inside of the housing.
Hoshiko, H. H.↗
Zero-angle helical coil
Device is constructed of bimetallic stock material formed into segments of small diameters and fastened together by metal strips. Coil is useful in various types of actuators, such as temperature controls.
Troendle, J. A.↗
Dynamic capacity and surface fatigue life for spur and helical gears
A mathematical model for surface fatigue life of gear, pinion, or entire meshing gear train is given. The theory is based on the statistical approach used by Lundberg and Palmgren for rolling-element bearings. Also equations are presented which give the dynamic capacity of the gear set. The dynamic capacity is the transmitted tangential load which gives a 90 percent probability of survival of the gear set for one million pinion revolutions. The analytical results were compared with test data for a set of AISI 9310 spur gears operating at a maximum Hertz stress of 1.71 billion N per sq m (248,000 psi) and 10,000 rpm. The theoretical life predictions were very good when material constants obtained from rolling-element bearing tests were used in the gear life model.
Coy, J. J.↗
Easily-assembled helical heater
Rugged, compact heater is made from 0.1 mm diameter Inconel wire (125 ohms per meter). Heating element is enclosed in PTFE heat-shrink sleeve. Ends of coal pass through small ceramic spools and are silver-brazed to lead wires. Junctions are potted in epoxy or silicon and covered with crimp sleeves and heat-shrink tubing.
Pizzeck, D. E.↗
The role of magnetic helicity in cosmic ray transport theory
It has been found that the computed values of the mean free path for pitch angle scattering of low rigidity cosmic rays computed from weak turbulence theory are systematically larger than the values inferred from analyses of solar particle events. Reasons for this discrepancy are considered, taking into account components of the spectral tensor of the magnetic field fluctuations which can contribute to pitch angle scattering. The contributions of the additional terms can be estimated from the interplanetary magnetic field. It is shown that these additional contributions can be significant. A description is given of a formalism which includes the possibility that the field magnitude is constant. The formalism provides a formal basis for the heuristic arguments made by Goldstein (1980).
Goldstein, M. L.↗
Evaluation of magnetic helicity in homogeneous turbulence
(Previously announced in STAR as N81-23900)
Matthaeus, W. H.↗
Lubricant jet flow phenomena in spur and helical gears with modified center distances and/or addendums for out-of-mesh conditions
Out-of-mesh jet lubrication of gears was examined. The pinion impingement cycle was described briefly. An analysis was developed for the lubricant jet flow in the out-of-mesh condition. The analysis provides for the inclusion of modified center distances and modified addendums. Equations were generated for the limit values of variables necessary to remove the severe limitations to facilitate computer analysis. A computer program was designed using these limit formulas to prevent negative impingement (missing) on the pinion.
Akin, L. S.↗
Automatic helical rotorcraft descent and landing using a microwave landing system
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Mcgee, L. A.↗
Lubricant jet flow phenomena in spur and helical gears with modified center distances and/or addendums - For out-of-mesh conditions
Out-of-mesh jet lubrication of gears was examined. The pinion impingement cycle was described briefly. An analysis was developed for the lubricant jet flow in the out-of-mesh condition. The analysis provides for the inclusion of modified center distances and modified addendum. Equations were generated for the limit values of variables necessary to remove the severe limitations to facilitate computer analysis. A computer program was designed using these limit formulas to prevent negative impingement (missing) on the pinion.
Akin, L. S.↗
Analytical models of helical wind-type astrophysical flows
Three classes of analytic solutions of the basic hydrodynamic equations assumed to govern plasma flow in the atmosphere of a rotating astrophysical object are presented. Attention is focused on the balance of the inertial and gravitational forces with suitable pressure gradients in the presence of rotation. The solutions are written in terms of dimensionless physical parameters in order to facilitate their direct application to specific astrophysical flows, such as winds from massive premain sequence objects and T Tauri stars, and bipolar flows in young stellar objects.
Tsinganos, K.↗