scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
Jens Krøll1
TL;DR: A combination of the procedures used in rocket immunoelectrophoresis and in line immunoe electrophorized together into an antiserumcontaining agarose gel permits a direct characterization of the antigen content in a number of samples by means of a known line spectrum.
Abstract: A combination of the procedures used in rocket immunoelectrophoresis (Chapter 2) and in line immunoelectrophoresis (Chapter 5) is applied. A series of samples are placed in circular application wells punched out in the contact gel close to the sample gel strip. Antigens contained in these samples are then electrophorized together into an antiserumcontaining agarose gel. The resulting sum pattern of rockets standing on the corresponding lines permits a direct characterization of the antigen content in a number of samples by means of a known line spectrum (Fig. 9.2).

99 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive analytical model which considers time and space development of the flow field in solid propellant rocket motors with high volumetric loading density is described, and the gas dynamics in the motor chamber is governed by a set of hyperbolic partial differential equations, coupled with the ignition and flame spreading events, and with the axial variation of mass addition.
Abstract: A comprehensive analytical model which considers time and space development of the flow field in solid propellant rocket motors with high volumetric loading density is described. The gas dynamics in the motor chamber is governed by a set of hyperbolic partial differential equations, that are coupled with the ignition and flame spreading events, and with the axial variation of mass addition. The flame spreading rate is calculated by successive heating-to-ignition along the propellant surface. Experimental diagnostic studies have been performed with a rectangular window motor (50 cm grain length, 5 cm burning perimeter and 1 cm hydraulic port diameter), using a controllable head-end gaseous igniter. Tests were conducted with AP composite propellant at port-to-throat area ratios of 2.0, 1.5, 1.2, and 1.06, and head-end pressures from 35 to 70 atm. Calculated pressure transients and flame spreading rates are in very good agreement with those measured in the experimental system.

99 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of particulate matter and boundary processes on linearized three-dimensional motions in a non-uniform flowfield is re-examined, and the results are applied to a problem of linear stability in solid propellant rocket motors.
Abstract: The problem oflinearized three-dimensional motions in a non-uniform flowfield is re-examined. Several modifications of the general analysis are effected: The influence of particulate matter is acounted for, to zeroth order, and certain boundary processes treated in earher one-dimensional computations are incorporated in an analysis applicable to any geometry. All processes occurring in combustion chambers are accommodated. As a specific example, the results are applied to a problem of linear stability in solid propellant rocket motors.

99 citations

Journal ArticleDOI
TL;DR: In this paper, the interaction between acoustic waves and gas-phase flame dynamics of a double-base homogeneous propellant in a rocket motor has been studied by means of a comprehensive numerical analysis.
Abstract: The interactions between acoustic waves and gas-phase flame dynamics of a double-base homogeneous propellant in a rocket motor has been studied by means of a comprehensive numerical analysis. The formulation treats the complete conservation equations of mass, momentum, energy, and species concentration, and accounts for finite rate chemical kinetics in the gas phase and subsurface reactions. The model has been implemented to examine the detailed flow structures and heat-release mechanisms in various parts of the motor, including microscale motions near the propellant surface and macroscale motions in the bulk of the chamber. Results indicate that strong interactions between exothermic reactions and acoustic waves occur in regions with steep temperature gradients due to the large activation energy of the associated chemical kinetics. The dynamic behavior of the luminous flame plays a decisive role in determining the motor stability characteristics. Distributed combustion response in the gas phase provides the energy for driving flow oscillations, and can be treated correctly as a combination of monopole and dipole sources based on acoustic theory.

98 citations

Journal ArticleDOI
TL;DR: In this paper, three potential origins of side loads were observed and investigated, namely, the pressure fluctuations in the separation and recirculation zone due to the unsteadiness of the separation location, the transition of separation pattern between free-shock separation and restricted shock separation, and aeroelastic coupling, which indeed cannot cause but do amply existing side loads to significant levels.
Abstract: The operation of rocket engines in the overexpanded mode, that is, with the ambient pressure considerably higher than the nozzle exit wall pressure, can result in dangerous lateral loads acting on the nozzle. These loads occur as the boundary layer separates from the nozzle wall and the pressure distribution deviates from its usual axisymmetric shape. Different aerodynamic or even coupled aerodynamic/structural mechanic reasons can cause an asymmetric pressure distribution. A number of subscale tests have been performed, and three potential origins of side loads were observed and investigated, namely, the pressure fluctuations in the separation and recirculation zone due to the unsteadiness of the separation location, the transition of separation pattern between free-shock separation and restricted-shock separation, and aeroelastic coupling, which indeed cannot cause but do amply existing side loads to significant levels. All three mechanisms are described in detail, and methods are presented to calculate their magnitude and pressure ratio at which they occur.

97 citations


Network Information
Related Topics (5)
Boundary layer
64.9K papers, 1.4M citations
77% related
Nozzle
158.6K papers, 893K citations
76% related
Turbulence
112.1K papers, 2.7M citations
75% related
Solar wind
26.1K papers, 780.2K citations
75% related
Combustion
172.3K papers, 1.9M citations
75% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202211
2021373
2020480
2019624
2018537
2017493