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Rocket

About: Rocket is a research topic. Over the lifetime, 14018 publications have been published within this topic receiving 95852 citations. The topic is also known as: rockets.


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Journal ArticleDOI
TL;DR: In this paper, an alternative derivation of the dissipative results is provided, based on perturbation analysis of the undamped characteristic values and yields additional insight into the stability results.
Abstract: Onehypothesisforexplainingtheconinginstabilitiesobservedincertainspinningaxisymmetricsolidfuelrockets attributes the source of the instability to the accumulation of slag near the exit of the rocket casing. Previously this hypothesis was explored using a particle model with elastic restoring forces to represent the slag motion. A recent paper further examines how the results are modie ed when dissipative forces are added to the model. The work is based on the second method of Lyapunov. An alternative derivation of the dissipative results is now provided. The new derivation is based on perturbation analysis of the undamped characteristic values and yields additional insight into the stability results. A numerical example simulating the coning instability is also given. It shows that a coning growth similar to that observed in space is possible assuming certain time histories of spacecraft parameters. The example requires the natural frequency of moving mass to beclose to thenominal spacecraft spin rate to produce the coning instability. In addition to their relevance for the specie c problem of spinning rocket stability, the results presented provide insight on how the maximum axis spin rule for torque free spinning bodies is modie ed in the presence of thrust.

44 citations

Journal ArticleDOI
TL;DR: In this article, current measurements obtained by the two sections of the Cooperative High Altitude Rocket Gun Experiment-2 sounding rocket, a mother vehicle carrying a 1-keV electron gun and a daughter vehicle tethered to the mother, compared with the results of previous models of current collection by a charged conductor in a plasma.
Abstract: Currents measurements obtained by the two sections of the Cooperative High Altitude Rocket Gun Experiment-2 sounding rocket, a mother vehicle carrying a 1-keV electron gun and a daughter vehicle tethered to the mother, are compared with the results of previous models of current collection by a charged conductor in a plasma. The current collection of the daughter vehicle, a conducting body in the ionosphere, is found to agree with the Parker-Murphy (1967) limit. The additional current collection found for the mother vehicle is attributed to beam-plasma interactions.

44 citations

Journal ArticleDOI
TL;DR: In this article, a numerical reconstruction of a series of test data obtained with static firings of a lab-scale hybrid rocket is carried out with a Reynolds-averaged Navier-Stokes solver including detailed gas-surface interaction modeling based on surface mass and energy balances.
Abstract: A numerical rebuilding of a series of test data obtained with static firings of a lab-scale hybrid rocket is carried out with a Reynolds-averaged Navier–Stokes solver including detailed gas–surface interaction modeling based on surface mass and energy balances. Two experimental campaigns are considered in which gaseous oxygen is fed into axisymmetric hydroxyl-terminated polybutadiene grains through an axial conical subsonic nozzle. A validation rebuilding of all of the firing tests has been performed first to highlight numerical prediction capabilities and modeling limits. Despite the several geometrical simplifications, which allows using a reduced number of cells in the computational domain and thus performing parametric analyses efficiently, the present computational fluid dynamics approach is able to capture the main features of the motor internal ballistics, fairly reproducing the average chamber pressure values and the fuel regression rate trends with oxidizer mass flux and port diameter. Computed f...

44 citations

Journal ArticleDOI
TL;DR: In this article, a rocket technique for measuring electron density and collision frequency in the lower ionosphere is described, where absolute values of electron density were determined by a radio propagation experiment, and detailed height variations were measured with a Langmuir probe.

44 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe the development of an inflatable concentrator for solar propulsion, providing the source of heat to a hydrogen engine aboard the Solar Rocket, a device designed to carry payloads from a low earth orbit (LEO) to a geosynchronous orbit (GEO) at significant mass savings in comparison to chemical propulsion; it involves two light-weight parabolic reflectors in an off-axis configuration focusing solar radiation into the absorbers of the engine, which causes the emission of a hot hydrogen jet.
Abstract: This paper describes the development of an inflatable concentrator for solar propulsion, providing the source of heat to a hydrogen engine aboard the Solar Rocket. The latter is a device designed to carry payloads from a low earth orbit (LEO) to a geosynchronous orbit (GEO) at significant mass savings in comparison to chemical propulsion; it involves two light-weight parabolic reflectors in an off-axis configuration focusing solar radiation into the absorbers of the engine, which causes the emission of a hot hydrogen jet. Each of the reflectors has an elliptical rim with a 40 m major axis, providing heat to the propellant sufficient to produce about 40 lbs. of thrust. The same concentrator concept is contemplated for space power application to focus solar radiation on a conversion device, e.g., a photovoltaic array or the high temperature end of a dynamic engine. Under the present project, a one-fourth scale, 9X7 m off-axis inflatable concentrator has been under development as a pilot for the full-scale flight unit. The reflector component consists of a reflective membrane made of specially designed gores and a geometrically identical transparent canopy. The two form together an inflatable lenslike structure which, upon inflation, assumes the accurate paraboloidal shape. Thismore » inflatable structure is supported along its rim by a strong, bending-resistant torus. The paper describes the development of this system including the analysis leading to determination of the gore shapes, the reflector membrane design and testing, the analysis of the supporting torus, and a discussion of the effects of the space environment.« less

44 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202211
2021373
2020480
2019624
2018537
2017493