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.

High-Pressure Bipropellant Microrocket Engine

Abstract: The development of high-aspect-ratio, high-precision micromachining in silicon or silicon carbide suggests the feasibility of microfabricated, high-chamber-pressure chemical rocket engines. With high-speed turbopumps and valvesincorporatedontotherocketchip,anumberofpropulsioncyclesarepossible.Suchanengine,approximately 20 ££ 15 £ 3 mm in size, operating at a 125-atm chamberpressure, would produceabout 15 N of thrust using 300-s Isp propellants at a thrust-to-weight ratio of 1000:1. The feasibility of these engines has been investigated, and a liquid-cooled, pressure-fed thrust chamber and nozzle have been successfully designed, fabricated, and operated at a 12.5-atm chamber pressure to further evaluate the concept.

Characterization of Cryogenic Injection at Supercritical Pressure

Abstract: Understanding the Complex environment of the rocket chamber involves good knowledge of the injection phenomena. Understanding the injection phenomena allows the rocket designer to employ time and cost saving modeling tools to design a higher performance rocket engine. The rocket engine performance is highly dependent on the injection processes within the chamber. This project looked at injection processes in the supercritical regime of the injected fluid, cryogenic nitrogen, in order to better understand realistic conditions in the rocket engines of today. The investigation considered test conditions from 4.0 to 6.0 MPa at two different injection velocities and temperatures. Experimental data taken by Raman imaging and Shadowgraphy were compared to computational models for these various test conditions. The test data allows comparisons of density, length scales and jet spreading angles. The results validate the computational models fairly well and agree with classical theory.This agreement allows further use of the models to predict injection behavior under these operating conditions. Also, further comparisons were made between the various test cases using the computational models to consider the effects of pressure, velocity and temperature variations on the cryogenic jet.

Influence of a Conical Axial Injector on Hybrid Rocket Performance

Abstract: This paper was aimed at analyzing the static engine firings results obtained by means of a hybrid rocket where gaseous oxygen was supplied into axial-symmetric polyethylene cylindrical grains through two different injector configurations: an axial conical subsonic nozzle and a radial injector. The axial injector is considered interesting because of its easy design and the remarkable feature that it produces no significant pressure oscillations for the stabilizing effect due to the hot gas recirculation zone established within the combustion port. To take advantage of its qualities, the assessment of the regression rate variations under the flow field generated by this configuration is required. For the investigated set of operating conditions, the instantaneous regression rates exhibit a time-and-space dependence caused by the impinging jet zone dynamics, while the average regression rates are higher and less mass flux dependent than those achieved with the radial injection motor and expected from the turbulent flow through pipes. A comparison to the data from the radial injector was further drawn in terms of combustion efficiency, fuel consumption profiles, and combustion stability. The radial injector, at the same mass flux and pressure, produces lower regression rates, high pressure oscillations and worse combustion efficiency at the same L*, but more uniform fuel consumption.

Lower ionosphere electron concentration and collision frequency from rocket measurements of Faraday rotation, differential absorption, and probe current

Abstract: Lower ionosphere electron density profiles and collision frequency using rocket radio propagation data with magnetoionic theory