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.

Effect of solid particles on electromagnetic properties of rocket exhausts

Abstract: This paper presents a discussion of the effect of solid particles on the electromagnetics of rocket exhausts and the physics of a technique for reduction of electron density. It is seen that the presence of solid particles of low work function can account for the very high electron densities in rocket exhausts and that the electron density can be considerably reduced by the addition of solid particles of a material of high work function.

Computational Fluid Dynamics Simulations of a GO2/GH2 Single Element Combustor

Abstract: solution is obtained on a mesh with 1.5 million nodes. The complexity of the model is gradually increased until the model is capable of predicting the wall heat flux. The analysis of numerical results shows a significant effect of boundary conditions on wall heat flux predictions. The comparison of the Reynolds-averaged Navier–Stokes simulationswiththeexperimentaldatademonstratesthecapabilityofReynolds-averagedNavier–Stokessimulations to predict wall heat fluxes in a rocket combustion chamber.

Design of Multiport Grain with Hydrogen Peroxide Hybrid Rocket

Abstract: A high length-to-diameter ratio of a rocket leads to unstable flight performance, affects structural loads, and makes a high dry mass of the rocket with a diameter constraint. To improve the volume...

CFD Simulation of a Hybrid Rocket Motor with Liquid Injection

Abstract: In this paper, a commercial CFD code is used to simulate different hybrid rocket motor configurations applying liquid N2O as the oxidizer and paraffin wax as the fuel. This work is the prosecution of a previous study performed to simulate hybrid rockets with diaphragms of different geometries placed inside the combustion chamber, where N2O was injected in gaseous phase, instead of using liquid. With respect to the previous study, liquid injection has been introduced, together with the droplets vaporization inside the combustion chamber and their full coupling with the eulerian gas phase, in terms of both heat exchange and momentum exchange. The main objective is the description of the proper numerical models to be applied in test cases in which liquid injection has to be represented. The most important differences with respect to the simulations where only gas is injected are also discussed. In order to validate the CFD output, experimental results coming from two different design scales are used: a laboratory scale and an increased scale. For each of these two scales, different rocket configurations and geometries have been studied. The different geometries studied include: a lab-scale rocket with a cylindrical grain and with a 4-hole diaphragm inserted at the 24% of the grain length, a 1-hole diaphragm lab-scale motor and an increased-scale hybrid rocket with a 1-hole diaphragm and without any diaphragm. For each test case, a comparison with the related experiment is presented and discussed. The simulations have been run in steady state conditions, with simplified chemical reactions, liquid oxidizer injection and no paraffin entrainment. The simulations show a good agreement with the experimental results of the different rocket configurations analyzed: the maximum error on efficiency is 7%. The CFD predicts (both in the case of gas and liquid injection) a higher efficiency for the rocket geometries provided with a diaphragm with respect to the same geometries without a mixing device and this is in accord with experiments. CFD results also show some peculiar phenomena about liquid injection.

Rocket Nozzle Cold-Gas Test Campaigns for Plume Investigations

Abstract: Within a joint research effort of Astrium and DLR, cold-gas test campaigns with subscale nozzles were performed to investigate a) the wall heat flux for separated nozzle flows, and b)the plume pattern for an overexpanded supersonic free-jet nozzle flow. For both test campaigns, a thrust-optimized, parabolic nozzle was the subject of investigation. This type of rocket nozzle, frequently used in the Western world for rocket engines, features two separation patterns during start-up and shut-down, or for engine operation with chamber pressures not sufficient to reach full-flowing in the nozzle extension, the classical free shock separation and restricted shock separation. The objective of both test campaigns was the investigation of the wall heat transfer in both separation patterns, and the investigation of the cap-shock pattern which special emphasis on the partly subsonic core vortex at the centreline. Wall temperatures were measured by infrared thermography, showing that a local heat flux increase is observed in the incipient separation. Furthermore, the formation of vortexes near the wall was observed. For the plume investigation, the core vortex was resolved by means of threads and laser induced grids. Experimental results for the core vortex position were compared with numerical flow field analyses.