The noisiness of impulsive sounds
Impulsive sound signals perceived noisiness in anechoic chamber, investigating duration, intersignal interval, repetition and frequency effects
Fidell, S.↗
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Results for “impulse”
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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Application of an impulsive trajectory optimization method to the comet rendezvous problem
Multiple impulsive spacecraft trajectory optimization technique application to comet rendezvous problem, using computer program
Waters, J. I.↗
Impulsive hard X-ray and ultraviolet emission during solar flares
Impulsive hard X ray and far UV emission during solar flares
Donnelly, R. F.↗
Minimum delta-V, three-impulse, non-coplanar transfer from a circular parking orbit onto an asymptotic velocity vector for small declination angles - An approach to the trans-Mars launch window problem
Trans-Mars launch window problem, discussing minimum delta-V three-impulse noncoplanar transfer from circular parking orbit onto asymptotic velocity vector
Bean, W. C.↗
Inequality constraints in primer-optimal, N-impulse solutions
Inequality constraints in primer optimal N impulse solutions, introducing penalty function and its gradient with respect to control variables
Faust, N. L.↗
Large impulses of self-magnetic origin
Self magnetic impulses in gas discharge configuration as function of current and anode- cathode radii ratio
Garrison, R. L.↗
Guidance and navigation requirements for unmanned flyby and swingby missions to the outer planets. Volume 2: impulsive high thrust missions, phase A
The impulsive, high thrust missions portion of a study on guidance and navigation requirements for unmanned flyby and swingby missions to the outer planet is presented. The proper balance between groundbased navigational capability, using the deep space network (DSN) alone, and an onboard navigational capability with and without supplemental use of DSN tracking, for unmanned missions to the outer planets of the solar system is defined. A general guidance and navigation requirements program is used to survey parametrically the characteristics associated with three types of navigation systems: (1) totally onboard, (2) totally Earth-based, and (3) a combination of these two.
Source record↗
Neutronics analysis of an open-cycle high-impulse gas core reactor concept
A procedure was developed to calculate the critical fuel mass, including the effects of propellant pressure, for coaxial-flow gas-core reactors operating at 196,600 newtons thrust and 4400 seconds specific impulse. Data were generated for a range of cavity diameter, reflector-moderator thickness, and quantity of structural material. Also presented are such core characteristics as upper limits on cavity pressure, spectral hardening in very-high-temperature hydrogen, and reactivity coefficients.
Whitmarsh, C. L., Jr.↗
Sudden impulses in the geomagnetotail and the vicinity
Explorer 33 magnetic field observations were analyzed to study the propagation of sudden impulses (SI) in the geomagnetic tail and the magnetosheath. Average speed of propagation in these regions is 760 km per sec with a range of 550 to 1230 km per sec. Most of the SI's have propagation speed close to that of the shock wave observed in this region. Positive SI is shown to have a positive change in the tail or magnetosheath and a negative SI has a similar negative change. Nine out of thirteen correlated SI's have their origin in the solar wind continuities, while four SI's possibly originate in the perturbations of the tail or magnetosheath field. It was found that the SI propagation is not confined to the tail region but has correlated effects in the magnetosheath. The propagation region studied was in 2000 to 0200 local time sector.
Patel, V. L.↗
Evaluation of electroexplosive devices by nondestructive test techniques and impulsive waveform firings
Special requirements of the space industry for more detailed knowledge of the quality and reliability of each electroexplosive device (EED) selected for use aboard a spacecraft are described. Statistical methods do not practically demonstrate the high reliability needed. To close this gap, nondestructive test techniques and instrumentation for 1-W/1-A no-fire devices have been developed. Several lots of squibs have been evaluated using these techniques and instrumentation. They yield data as to the quality and normal behavior of each electroexplosive device without firing or degrading the unit. Performance data were obtained by initiating the EED's with an impulsive waveform and sensing the initiation characteristics, sensitivity, and output.
Menichelli, V. J.↗
Effective specific impulse of external nuclear pulse propulsion systems
An investigation of a simple self-similar flow model for an external nuclear pulse propulsion system indicates that to achieve the high effective specific impulse of such a system three principal factors are required. The are (1) attaining pulses of optimum energy, (2) attaining good propellant collimation, and (3) using an ablative material for the pusher surface which has high absorptivity for radiant energy at the propellant stagnation temperature.
Reynolds, T. W.↗
A note on laminar shear flow over impulsively started bodies.
Prediction of the shear flow around bodies impulsively set into motion at a uniform velocity. Information is presented on the local wall shear stress, velocity distribution, steady flow times, and thermal response for wedge flows where local flow acceleration occurs. The essential features of the flow field are found to be describable by the approximate series expansion method of Goldstein and Rosenhead (1936). This method would appear to be useful in rapidly calculating the viscous drag on the forward face of various shaped bodies where local flow acceleration occurs.
Back, L. H.↗
Sudden impulses in the geomagnetotail and the vicinity.
Explorer 33 magnetic field observations have been analyzed to study the propagation of sudden impulses (si) in the geomagnetic tail and the magnetosheath. Average speed of propagation in these regions is 760 km per sec with a range of 550-1230 km per sec. Most of the si's have a propagation speed which is close to that of the shock wave observed in this region. Positive si is shown to have a positive change in the tail or magnetosheath and a negative si has a similar negative change. Nine out of thirteen correlated si's have their origin in the solar wind continuities, while four si's have possible origin in the perturbations of tail or magnetosheath field.
Patel, V. L.↗
Response of a seat-passenger system to impulsive loading.
This paper presents a summary of a study of the dynamic response of an aircraft seat-passenger system to impulsive loading typical of aircraft crash situations. A brief description of the computer model SIMULA is presented, and selected data from 305 separate cases which have been studied are discussed. Maximum system forces, displacements, velocities, and accelerations are presented as functions of velocity change, aircraft deceleration, crash pulse shape, passenger weight, and seat belt slack. Data from both single and coupled parameter studies are included. A correlation of SIMULA results with experimentally obtained data is made.
Collins, J. A.↗
Results of a space shuttle pulme impingement investigation at stage separation in the NASA-MSFC impulse base flow facility
Results are presented for an experimental space shuttle stage separation plume impingement program conducted in the NASA-Marshall Space Flight Center's impulse base flow facility (IBFF). Major objectives of the investigation were to: (1)determine the degree of dual engine exhaust plume simulation obtained using the equivalent engine; (2) determine the applicability of the analytical techniques; and (3) obtain data applicable for use in full-scale studies. The IBFF tests determined the orbiter rocket motor plume impingement loads, both pressure and heating, on a 3 percent General Dynamics B-15B booster configuration in a quiescent environment simulating a nominal staging altitude of 73.2 km (240,00 ft). The data included plume surveys of two 3 percent scale orbiter nozzles, and a 4.242 percent scaled equivalent nozzle - equivalent in the sense that it was designed to have the same nozzle-throat-to-area ratio as the two 3 percent nozzles and, within the tolerances assigned for machining the hardware, this was accomplished.
Mccanna, R. W.↗
Two impulse trajectory optimization for the RAE-B orbit trim problem
The results are reported of work on an appropriate approach to the solution of the optimum two-impulse transfer problem between orbits of specified inclination. The task included a literature search to identify the current state of the art and a definition of the suggested approach for the specific application of a lunar orbit trim. The applications of the results to the problem are included. The formulation for a computer program developed under this task following a more conventional approach is also included.
Payne, M. H.↗
Impulsive solar X-ray bursts: Bremsstrahlung radiation from a beam of electrons in the solar chromosphere and the total energy of solar flares
Analysis of various aspects of impulsive X-ray bursts (IXB's) has lead to the consideration of a model where the X-rays are produced by bremsstrahlung radiation from a beam of electrons directed toward the photosphere. It was found that in general the X-ray spectrum from such a beam will fall off more rapidly than when the effect of the beaming of radiation is neglected. Furthermore, the spectral index of the resulting X-rays appears to increase by about unity for X-ray energies 100 kev, a fact which may explain the observed cutoff in the spectrum of the IXB's. It is also shown that in such a model there is sufficient energy in the form of nonthermal electrons to explain the total energy (approximately 10 to the 32nd power ergs) of a flare.
Petrosian, V.↗
The impulsive X-ray burst of October 10, 1970.
An impulsive burst of 100-400 keV solar X-rays associated with a small solar flare was observed on October 10, 1970 with a large area scintillator aboard a balloon. The X-ray burst was also observed simultaneously in 10-80 keV range by the OGO-5 satellite and in 8-20 A range by the SOLRAD-9 satellite. The event is attributed to an H-alpha subflare located approximately at S13, E88 on the solar disk. The spectral characteristics of this event are examined in the light of the earlier X-ray observations of small solar flares.
Kane, S. R.↗