Download or read book Combined Experimental analytical Investigation of Afterburning Solid Rocket Exhaust Plume Properties to Improve Signature Level Prediction Capability written by and published by . This book was released on 1990 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes experimental work performed on a high-speed pre-mixed hydrogen-air jet flame in a co-flowing annular air flow in the presence and absence of base flow at the exit. Includes details on the high-speed flame in a coaxial air facility which was designed, built, and tested to simulate (in a first approximation) rocket exhaust flow conditions. In addition, a new high spatial resolution computer-controlled three-dimensional gear was built to traverse the investigated flow field. The main experimental tool was a two-dimensional laser Doppler velocimeter with data acquisition and processing system. The tool was used to measure the two main velocity components. Other measurements included turbulence intensities and mean temperatures at various downstream sections. The measured initial and flow field data will serve to evaluate the validity of various turbulence models and to predict the structure of rocket exhaust plumes. Moreover, the experiments established the effect of the base flow on the turbulence structure of the exhaust plume.
Download or read book Rocket Exhaust Plume Phenomenology written by Frederick S. Simmons and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 2000 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new book deals with the phenomenology of rocket exhaust plumes as the targets of space-based surveillance systems. Topics include the physical and chemical processes in rocket engines and their exhaust plumes, particularly in regard to flow properties, gas dynamics, and radiative mechanisms that are responsible for the generation of emission in rocket exhaust plumes at infrared and other wavelengths. System designers in a number of defense-related areas will be able to put the information in this book to immediate use.
Download or read book Rocket Plume Tomography of Combustion Species written by Joshua M. Kutrieb and published by . This book was released on 2001-12 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in accurate detection and targeting of aggressor missiles has received considerable interest with the national priority of developing a missile defense system. Understanding the thermal signatures of the exhaust plumes of such missiles is key to accomplishing that mission. Before signature models can be precisely developed for specific rockets, the radiation of the molecular or combustion species within those plumes must be accurately predicted. A combination translation/rotation scanning diagnostic technique has been developed to map the combustion species of a rocket plume and characterize its radiation properties. Using new infrared spectrometer and fiber optic cable technology to transmit the signal spectrum of interest, the custom designed mechanism can sweep through two dimensions of a steady-state rocket exhaust. A glow bar, or blackbody simulator, is shuttered on the opposite side of the plume, allowing the spectrometer to measure both the emission and absorption spectra. This thesis demonstrated the first time use of fiber optic cable to transmit infrared emission/absorption (E/A) spectra from a rocket plume to an infrared detector. This new fiber optic configuration allows for rapid translation and rotation around the rocket plume, establishing the capability for rapid spatial characterization of the combustion species present. Experimental results may then be compared to DoD rocket plume model predictions to highlight areas for improvement.
Download or read book Influence of Chemical Kinetic and Turbulent Transport Coefficients on Afterburning Rocket Exhaust Plume Properties written by H. S. Pergament and published by . This book was released on 1970 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of chemical kinetic and turbulent transport coefficients on afterburning rocket exhaust plume properties was analyzed in terms of predicted radar attenuations transverse to solid propellant plumes. A model of parallel turbulent mixing and nonequilibrium combustion and ionization was used to determine whether varying these coefficients, which are input data to the model, over their ranges of uncertainty has a significant effect on the predicted attenuation. The results of the study demonstrate that significant differences in predicted attenuation levels can result when the important reaction rate and turbulent transport coefficients are varied within their respective error bounds. This establishes the framework within which to interpret radar attenuation data taken at sea level and under simulated altitude conditions. It is also shown that a better laboratory determination of the rate coefficient for the dominant charge-producing reaction, K + Cl yielding K(+) + Cl( - ), is of particular importance if more accurate attenuation predictions are to be made. It was concluded that realistic calculations of solid propellant exhaust plume electrical properties must take chemical kinetics into account. (Author).
Download or read book Experimental Investigation in an Altitude Test Facility of Burning of Excess Combustibles in a Rocket Engine Exhaust written by Harry E. Bloomer and published by . This book was released on 1960 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Suppression of Afterburning in Solid Rocket Plumes by Potassium Salts written by and published by . This book was released on 1984 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exhaust plume of a minimum-smoke solid rocket contains significant concentrations of hydrogen and carbon monoxide which when mixed with ambient air react to water and carbon dioxide producing visible flash and increased infrared radiation. Both reactions produce undesirable signatures and interference with optical guidance systems. Potassium salts have been added to propellant charges to inhibit afterburning in both guns and rockets. They have not always been effective, the inhibiting effect of the salt being related to gas composition and temperature in a complex manner which is not completely understood. Further, there is disagreement as to whether it is KOH, KO2, or K that is most important in the afterburning suppression. The results are presented here of the first year of the investigation on the efficacy of each of these on the combustion of diluted H2/CO-O2-N2 mixtures. Potassium added to the fuel-side of a H2-CO-N2-O2 flat diffusion flame at near stoichiometry is more effective in inhibiting the flame reactions than KOH added to a H2-N2-O2 flame at a stoichiometric ratio of 0.61. A description is given of burner, optical and flow metering system used in experiments. Originator supplied keywords include: Rocket plume afterburning, Combustion, and Flame spectroscopy.
Download or read book Analysis and Correlation of High Altitude Rocket Exhaust Plume Experimental Data written by Larry R. Ring and published by . This book was released on 1973 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented of a study for evaluating the applicability and accuracy of rocket motor and exhaust plume gasdynamic analytical models. Evaluation of these analytical models was based upon correlation of analytical predictions with experimental data obtained in the High Altitude Plume Radiation Program. The effects of oxidizer-to-fuel ratio gradients, combustion efficiency, combustion chamber mixing, nozzle throat expansion and chemistry model were ascertained. Non-continuum effects and closed form analytical techniques were also considered. (Modified author abstract).
Download or read book Theory on Afterburning in a Low altitude Rocket Exhaust Plume written by Richard Shao-Lin Lee and published by . This book was released on 1968 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: An improved aerodynamic model is proposed for the exhaust plume issuing from a low-altitude rocket nozzle exit into quiescent ambient air in which chemical reactions and compressibility predominate. The model is based on the presently available knowledge and established aerodynamic principles for the various flow regimes involved. The major assumptions made are individually substantiated by related experimental evidence in existing literature. A theoretical analysis is carried over the whole flow region based on the Karman's integral approach to find solutions for the gross aerodynamic and thermodynamic behavior of the plume. Theory incorporating on empirically derived constants provides the required radial distribution function for the integration. Solutions are obtained for the velocity, density, temperature and chemical composition fields for extended regions of the plume. These results will provide the much needed framework for the understanding of the elements which contribute to the phenomenon of radar attenuation of rocket exhaust plumes. (Author).
Download or read book AFRPL Graphite Performance Prediction Program written by and published by . This book was released on 1976* with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: A combined experimental and analytic program was conducted to develop improved procedures for predicting the ablation performance of graphite materials in rocket nozzles. Particular emphasis was placed on conditions representative of the throat region of an MX nozle design which would use graphite materials that are representative of the current state of materials development. New kinetic response correlation functions were developed for G-90 and ATJ bulk graphites, 15% silicon carbide modified pyrolytic graphite, c plane pyrolytic graphite, and Pyrocarb 901 carbon-carbon. These functions were included into the Aerotherm GASKET code along with several modifications to improve on thermochemical modeling accuracy. This modified code, GASKET2, includes a number of new chemical species, improved generalized input requirements, and kinetically controlled carbon sublimation models. The GASKET2 code was used in a number of performance studies to predict the performance of a number of rocket nozzles to be tested in other Air Force programs. The rocket nozzle ablation performance prediction procedures for several rocket motor fabricators were mutually compared to determine the probable ranges of predicted variables. These ranges were used in an ablation rate sensitivity study to define the most critical parameters. The mass transfer coefficient and the kinetic rate constants were shown to be the most critical parameters to be accurately known. (Author).
Download or read book Kinetic Reaction Coefficients in Rocket Exhaust Plumes written by Kaare J. Nygaard and published by . This book was released on 1977 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pergament and Jensen recently have developed a model for estimating the densities of neutral and charged species for an afterburning plume of a solid fuel rocket as a function of distance along the plume. They have compared the predicted electron densities with experimental radar cross section measurements of electron density and find agreement at least within an order of magnitude. The predictions of the model are dependent on the accuracy with which the rate constants used are known. This report describes the work done under AFOSR 74-2672 toward rate constant measurements for those reactions that Pergament and Jenson pointed out as critical to the model and poorly known; dissociative attachment of electrons in HC1, collisional ionization of potassium and chlorine, and three body recombination of potassium. The reactions are closely related in the rocket plume, but diverse experimental procedures are required to measure the rates of the reactions. Potassium is a contaminant of the perchlorate oxidizer in some solid fuels, but because of its low ionization potential, it can make an inordinately large contribution to ionization in the plume.
Download or read book A Fully Coupled Underexpanded Afterburning Rocket Plume Program The AIPP Code Part 1 Analytical and Numerical Techniques written by H. S. Pergament and published by . This book was released on 1974 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive computer code has been developed to determine afterburning rocket plume characteristics over a wide altitude range. The code constitutes a significant advance over previous plume codes because it computes the plume shock structure while simultaneously accounting for turbulent mixing, nonequilibrium chemistry and gas/particle nonequilibrium effects. The capability of calculating properties in the subsonic region downstream of the Mach disc, downstream of the shock reflected from the triple point and in the far field has been incorporated into the code, but has not yet been debugged. This report describes the analytical and numerical techniques incorporated into the code, demonstrates that predictions of inviscid, chemically-frozen plume flows are as accurate as those obtained from a proven method of characteristics code and gives the results of some sample calculations for the SRAM missile.
Download or read book Evaluation of Afterburning Cessation Mechanisms in Fuel Rich Rocket Exhaust Plumes written by and published by . This book was released on 1998 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational study was conducted to identify fundamental physical processes governing the cessation or shutdown of the afterburning of fuel rich rocket exhaust with the atmosphere. Several mechanisms that have been proposed were examined which are: 1) a relaminarization phenomenon, 2) a Damkoehler number effect and 3) a classical flame extinction mechanism. Analysis of the simulation results revealed the relaminarization mechanism to be implausible while the Damkoehler number effect and the flame extinction mechanisms were found to be valid. The extinction mechanism was also found to dramatically alter the emission characteristics and enhance the shutdown behavior which has important implications with respect to radiative heat transfer to the body and missile intercept systems. This is a significant finding because strain rate induced extinction is a previously unrecognized phenomena occurring in rocket exhaust plumes during afterburning cessation.
Download or read book Experimental Investigation of Close range Rocket exhaust Impingement on Surfaces in a Vacuum written by Leonard V. Clark and published by . This book was released on 1970 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AFRPL Graphite Performance Prediction Program written by and published by . This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A combined experimental and analytic program was conducted to develop improved procedures for predicting the ablation performance of graphite materials in rocket nozzles. Particular emphasis was placed on conditions representative of the throat region of an MX nozle design which would use graphite materials that are representative of the current state of materials development. New kinetic response correlation functions were developed for G-90 and ATJ bulk graphites, 15% silicon carbide modified pyrolytic graphite, c plane pyrolytic graphite, and Pyrocarb 901 carbon-carbon. These functions were included into the Aerotherm GASKET code along with several modifications to improve on thermochemical modeling accuracy. This modified code, GASKET2, includes a number of new chemical species, improved generalized input requirements, and kinetically controlled carbon sublimation models. The GASKET2 code was used in a number of performance studies to predict the performance of a number of rocket nozzles to be tested in other Air Force programs. The rocket nozzle ablation performance prediction procedures for several rocket motor fabricators were mutually compared to determine the probable ranges of predicted variables. These ranges were used in an ablation rate sensitivity study to define the most critical parameters. The mass transfer coefficient and the kinetic rate constants were shown to be the most critical parameters to be accurately known. (Author).
Download or read book Effects of Entrained Water and Strong Turbulence on Afterburning Within Solid Rocket Motor Plumes written by Richard I. Gomberg and published by . This book was released on 1978 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Plume Rise from Titan IV Rocket Launches written by Joseph D. Brands and published by . This book was released on 1997-12-01 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space launches at Cape Canaveral Air Station (CCAS) and Vandenberg Air Force Base (vAFB) produce exhaust ground clouds from the solid rocket boosters and liquid hypergolic fuels containing several toxic substances. In order to estimate the health effects that would be imposed upon the public by scheduled launches, range safety officials rely on the Rocket Exhaust Effluent Diffusion Model to predict ground level concentrations of these substances. A drawback to the REEDM is its underprediction of the initial ground clouds stabilization height. This underprediction causes an overprediction of the ground level toxic substance concentrations. This thesis focused on increasing the accuracy of the clouds stabilization height. Therefore, a model was developed incorporating conservation principles of volume, momentum, and buoyancy to predict stabilization height values. As part of the model a predictive function for the coefficient of entrainment was developed based on meteorological conditions. This rate of entrainment is a critical factor in accurately predicting the rise behavior of ground exhaust clouds.
Download or read book A Study of Rocket Exhaust Particles written by and published by . This book was released on 1910 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The exhaust -plumes generated by rocket motors are of significant military importance for missile detection, recognition and communication due to their electromagnetic emission and propagation properties. The plume is a high temperature, high velocity stream of gas and particles, into which the surrounding air is entrained. With improvements in the modelling of plume gas chemistry and turbulence, particles present in the plume have become more important in the computational prediction of the plume's flow field, and the subsequent prediction of plume emission and propagation characteristics. This thesis describes research on plume particles, including the measurement of their physical characteristics and the addition of two phase coding (ie. particles) into current plume prediction software. Particle collections were carried out in plumes produced by rocket motors with double base and composite propellants (including aluminised). The collected particles were analysed to establish their chemical composition and size distribution. A laser Doppler anemometer system was successfully used to measure particle velocities in the plumes of 1.5kN double base motors. Particle tracking software was used to trace the paths of particles using a simplified prediction of the plume and it was found that the predicted particle behaviour was analogous to that measured experimentally. Project management software was used during the research and its relevance was assessed in respect to the project's size and nature. The management of experimental trials was studied and a methodology formulated to help improve their future operation. The costs and benefits of the research were assessed and compared to other research projects. Many of the benefits gained, such as measurement techniques, require marketing to ensure that they are exploited in the future. Recommendations for future research are given that should enhance the present work.
