Download or read book Erosive Burning Study of Composite Solid Propellants by the Reacting Turbulent Boundary layer Approach written by Mohan Kishen Razdan and published by . This book was released on 1979 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosive Burning Studies of the Composite Solid Propellants by the Reacting Turbulent Boundary layer Approach written by Mohan Kishen Razdan and published by . This book was released on 1976 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of the current research is to achieve a basic understanding of the erosive burning mechanism in solid-propellant rocket motors. Both theoretical and experimental studies are undertaken. In the theoretical modeling, a reactive turbulent boundary-layer approach is used to analyze the erosive burning phenomenon. A second-order turbulent closure has been selected in the theoretical formulation. The theoretical model can be used to study the effect of gas velocity, pressure, streamwise pressure gradient, oxidizer particle size, and oxidizer-to-fuel ratio. For model validation, a test rig has been designed to establish a two-dimensional, turbulent boundary layer flow over a flat plate. The test rig can operate under various gas-dynamic conditions. A laser-photodiode servomechanism has been developed to measure the burning rate, and preliminary tests have demonstrated successful operation of the apparatus. (Author).
Download or read book Turbulent Boundary Layer Analysis and Experimental Investigation of Erosive Burning Problem of Composite Solid Propellants written by Mohan K. Razdan and published by . This book was released on 1978 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to investigate the frequently encountered phenomenon of erosive burning of composite solid propellants in rocket motors. Both theoretical and experimental studies were undertaken. In the theoretical model, the propellant burning process was described by considering a steady, two-dimensional, chemically reacting, turbulent boundary layer over a propellant surface. The diffusion-controlled gas-phase chemical reaction was modeled on the basis of the eddy-break-up concept. The theoretical model, comprised of a set of partial differential equations, was solved numerically. In the experimental work, a flat composite-propellant slab was burned in a test chamber by the flow of hot combustion gases which formed a turbulent boundary layer over the surface of the propellant. The burning rate of the propellant was measured by a high-speed motion picture technique at various pressures and free-stream velocities. Comparison of the theoretical results with the experimental data, obtained from the present study and that obtained from existing literature, showed a close agreement.
Download or read book A Reacting Turbulent Boundary Layer Approach to Solid Propellant Erosive Burning written by Robert A. Beddini and published by . This book was released on 1977 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: A theoretical analysis of the erosive burning of solid propellants is presented using a reacting turbulent boundary layer approach. The turbulent field is modeled using the second-order closure technique and a single-step gas-phase reaction is assumed for the combustion of a homogeneous propellant. The calculated results agree with the generally observed erosive burning trends of threshold velocity, nonlinear recession-ratio velocity dependence, pressure dependence, and normal burning rate sensitivity. For constant external velocity boundary layers, the results show a decrease in burning rate along the propellant surface, which also has been observed experimentally. Examination of calculated profiles of temperature and turbulent correlations in the boundary layer reveals that erosive burning is predominantly caused by flame zone broadening due to the diffusive effects of turbulence. (Author).
Download or read book Experimental and Analytical Study of Erosive Burning of Solid Propellants written by Merrill K. King and published by . This book was released on 1979 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: At Atlantic Research, erosive burning characteristics of eleven composite propellants were measured and found to agree well with predictions of a simplified first-generation model under most conditions. A second-generation more fundamental model for predicting burning rate versus pressure and cross flow velocity, given only compositional data, also yield predictions in close agreement with data. The most important parameter affecting crossflow sensitivity was no-cross flow burning rate, erosion sensitivity decreasing with increasing base rate. ARAP completed modifications to its SPEC model to enable calculation of cylindrical flows and performed preliminary evaluation for cold-flow simulations and erosive burning. Motor port diameter was identified as a key erosive burning scaling parameter through its effect on threshold conditions, and a simplified scaling relation was developed and verified. In addition, ARAP investigated the effects of combustion-turbulence interaction on predicted erosive burning. Penn State measured erosive burning rates of three AP-composite formulations in a device designed to give a well-defined turbulent boundary layer. The data agreed well with predictions made using a Penn State model based on a 2D turbulent boundary layer approach. Correlations relating burning rate to free stream velocity, and pressure were developed. The model was also extended to axisymmetric cylindrical port flow. (Author).
Download or read book Erosive Burning of Composite Solid Propellants Experimental and Modeling Studies written by and published by . This book was released on 1978 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental apparatus designed for measurement of erosive burning rates at crossflow velocities up to Mach 1 has been used to determine the erosive burning characteristics of seven propellant formulations with systematically varied properties. A composite propellant erosive burning model based on the bending of columnar diffusion flames gives reasonably good agreement with the measured erosive burning data over a wide range of conditions, breaking down only in regions where the fuel-oxidizer gas stream mixing does not control burning rate. Propellant base (no-crossflow) burning rate is found to have a predominant effect on sensitivity to crossflow (higher- burning-rate formulations being considerably less sensitive) whether the base burning rate differences are produced by oxidizer particle size variation, oxidizer/fuel ratio variation, or use of catalysts. Comparison of erosive burning predictions using the erosive burning model described herein with flow profiles expected to prevail in the test apparatus to predictions using profiles believed to exist in cylindrically-perforated motor grains indicate that erosive burning may be considerably less for a given mainstream crossflow velocity in such a motor than in the typical erosive burning test apparatus, a result quite important to extrapolation of test apparatus erosive burning data to actual motor conditions.
Download or read book An Analytical and Experimental Investigation of the Erosive Burning of Composite Propellants written by Merrill K. King and published by . This book was released on 1977 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Augmentation of solid propellant burning rate often occurs in the presence of strong product gas flow across the burning surface: This phenomenon is referred to as erosive burning. Increasing use of motors with low port-to-throat area ratios (including nozzleless motors) is leading to increased occurrence and severity of erosive burning. A first generation model based upon bending of columnar diffusion flames by a crossflow, permitting prediction of the effect of high-velocity crossflow on the burning rate of a composite propellant given only the zero-crossflow burning rate characteristics, is briefly summarized and compared with data. A second generation model (currently under development) which does not require even zero-crossflow burning rate data, using only composition and particle size as input, is outlined. In addition, a test device permitting extensive characterization of burning rate-pressure-crossflow velocity relationships for various propellants with direct continuous measurement of instantaneous burning rate by high-speed cinematography is described, and results of a series of tests with four propellants are presented. These tests indicate that the first generation composite propellant erosive burning model has reasonable good predictive capability, particularly in the higher pressure region where the propellant combustion is dominated by the propellant heterogeneity.
Download or read book Nonsteady Burning and Combustion Stability of Solid Propellants written by Luigi De Luca and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 1992 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Weinmarische Freuden post written by and published by . This book was released on 1633 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosive Burning of Composite Solid Propellants written by and published by . This book was released on 1979 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The erosive burning characteristics of a series of eight composite solid propellants with systematically varied composition and particle size parmeters have been measured over a wide range of pressures and crossflow velocities. Predictions of erosive burning made using a simplified version of a composite propellant erosive burning model based on columnar diffusion flame bending have been found to agree reasonably well with data, except under conditions where the propellant heterogeneity is unimportant. Theory and experiment both indicate an increase in erosion sensitivity with increased pressure over the range of conditions studied. It appears that the dominant factor influencing the sensitivity of composite propellant burning rate to crossflow is the base (no crossflow) burning rate versus pressure behavior of the propellant (lower base burning rate leading to increased crossflow sensitivity), with other factors having at most a second order effect except through their influence on base burning rate. Emphasizing this point, three propellants with widely differing compositional and ingredient particle size parameters, but with essentially the same base burning rate versus pressure relationship, exhibited nearly identical erosive burning characteristics.
Download or read book Erosive Burning of Composite Propellants written by and published by . This book was released on 1976 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing use of solid rocket motors with low port-to-throat area ratios, including the ultimate case of nozzleless motors, is leading to increased occurrence and severity of burning rate augmentation due to flow of propellant products across burning propellant surfaces (erosive burning). A review of the literature regarding this phenomenon indicates a lack of systematic data defining the effects of propellants formulation variables on the sensitivity of burning rate to crossflow velocity and the absence of a realistic predictive model for composite propellant burning rate-pressure-velocity relationships. In this paper, a physically realistic picture of the effect of crossflow velocity on composite propellant combustion is presented and a relatively simple analytical model based upon this picture is developed for prediction of composite propellant burning rate as a function of pressure and crossflow velocity, given only the burning rate-pressure relationship in the absence of cross-flow. In addition, hardware developed for testing erosive burning effects at cross flow Mach numbers up to 1.0 is described and a planned systematic test matrix is defined. Preliminary test results are included and compared with predictions made using the aforementioned analytical model.
Download or read book Erosive Burning Rate Studies of Composite Propellants Under High Crossflow Velocities written by S. Krishnan and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fast Reactions in Energetic Materials written by Alexander S. Shteinberg and published by Springer Science & Business Media. This book was released on 2008-09-26 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern energetic materials include explosives, blasting powders, pyrotechnic m- tures and rocket propellants [1, 2]. The study of high-temperature decomposition of condensed phases of propellants and their components (liquid, solid and hybrid) is currently of special importance for the development of space-system engineering [3, 4]. To better understand the burning mechanisms (stationary, nonstationary, - steady) of composite solid propellants and their components, information about the macrokinetics of their high-temperature decomposition is required [5]. To be able to evaluate the ignition parameters and conditions of safe handling of heat-affected explosives, one needs to know the kinetic constants of their high-temperature - composition. The development of new composite solid propellants characterized by high performance characteristics (high burning rates, high thermal stability, stability to intrachamber perturbations, and other aspects) is not possible without quanti- tive data on the high-temperature decomposition of composite solid propellants and their components [6]. The same reasons have resulted in signi?cant theoretical and practical interest in the high-temperature decomposition of components of hybrid propellants. It is known that hybrid propellants have not been used very widely due to the low bu- ing (pyrolysis) rates of the polymer blocks in the combustion chambers of hybrid rocket engines. To increase the burning rates it is necessary to obtain information about their relationships to the corresponding kinetic and thermophysical prop- ties of the fuels.
Download or read book A Model of Erosive Burning of Composite Propellants written by Merrill K. King and published by . This book was released on 1977 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of solid rocket motor designs which result in high velocity flows of product gases across burning propellant surfaces(notably, nozzleless rocket motors) is leading to increased occurrence of erosive burning. In this paper, a physically realistic picture of the effect of such crossflow on composite propellant combustion, based on the bending of columnar diffusion flames by the crossflow, is presented. This bending results in shifting of the diffusion flame heat release zone toward the surface, with consequent increased heat feedback flux from this flame to the surface and thus increased burning rate. A relatively simple analytical model based on this picture is developed for prediction of propellant burnings rate as a function of pressure and crossflow velocity, given only zero-crossflow burning rate versus pressure data. Model predictions and experimental results are compared, with reasonably good agreement being found. (Author).
Download or read book Response of Solid Propellant Combustion to the Presence of a Turbulent Acoustic Boundary Layer written by Ted Anthony Roberts and published by . This book was released on 1988 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Composite Solid Propellant Burning Rate Temperature Sensitivity written by Duane Arnold Baker and published by . This book was released on 1973 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt:
