[PDF] Statistical Analysis Of Steady State Combustion Of Nonmetallized Composite Solid Propellants eBook

Author : R. L. Glick
Publisher :
Page : 56 pages
File Size : 17,31 MB
Release : 1977
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The combustion model including aluminum and iron oxide was employed to correlate data bases of Miller and Maykut. Results for additive free formulations were excellent for both rate and exponent; results for formulations with aluminum and aluminum plus iron oxide were poor. A new method for extracting particle size dependent information from rate/response function/formulation data was developed from the statistical methodology itself and employed to process the aforementioned data bases. Results were encouraging; Miller's additive free and aluminum plus iron oxide data correlated very well; Miller's aluminum data showed that the increasing aluminum particle size increases interactions between oxidizer modes; Maykut's data base showed that aluminum induced interactions among oxidizer modes are decreased as iron content increases. Results elucidate mechanisms for rate, exponent, and response function control and show that the equal rate hypothesis employed in much combustion modeling is incorrect. A new approach for including the effects of transients introduced by particle size dependent rates in both steady and nonsteady combustion modeling was conceived. (Author).

Author : R. L. Glick
Publisher :
Page : 64 pages
File Size : 41,45 MB
Release : 1978
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A general method for extracting particle size dependent information from experimental rate/formulation data was developed from the statistical methodology. This technique was employed to correlate the data bases of Miller. Results showed that, by employing an interaction parameter of 4, both additive and additive free data could be correlated to standard error of estimate below 10.5%. The effect of steady radiant energy deposition on steady and nonsteady burning was explored. Results showed that if the radiant energy deposited in the reactive zones is negligible (an excellent assumption for low signature propellants) the effect of radiant energy deposition can always be accounted for by substituting the radiation augmented initial temperature for the initial propellant temperature.

Author : R. L. Click
Publisher :
Page : 118 pages
File Size : 18,14 MB
Release : 1976
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A statistical frame work capable of extending any monodisperse combustion model (steady or nonsteady) to propellants with mixed, polydisperse oxidizer was developed. The BDP model was modified to conform to the ensemble averaging requirements of the method and embedded therein. Methods to include ellipsoidal particles and additives were explored and omissions in the BDP model were corrected. An operational FORTRAN IV code is available for polydisperse, additive free AP propellants. A hydraulic analog of a T-burner was constructed and employed to explore vent flow phenomena. Results show flow downstream of vent is a Karman vortex street created by periodic flow separation/attachment on alternate sides of vent as burner flow oscillates. Examination of Culick's one-dimensional theory has shown that vent gain prediction is a result of an improper boundary condition; proper condition yields null vent condition. A consistent method to deduce performance data from motor test data when pressure, time history is nonneutral was derived. (Author).

Author : R. L. Glick
Publisher :
Page : 79 pages
File Size : 30,8 MB
Release : 1975
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Monodisperse BDP combustion model was extended to nonmetallized propellants with mixed, polydisperse oxidizers by embedding monodisperse model in statistical framework including mixture ratio effects. Basically, polydisperse propellant is 'disassembled and rearranged' to form sequence of monodisperse pseudo-propellants whose rates are computed via monodisperse model. Reassembly provides real propellant's burning rate. Approach provides information pertaining to distribution of regression rates and surface structure among different size oxidizer particles. Preliminary results suggest that significant factor in rate increases wrought by introduction of small oxidizer modes is mixture ratio alternations in larger modes. Hydraulic T-burner analog was constructed and employed to visualize vent flow phenomena. Studies showed that flow enters vent with axial momentum and that momentum is partially transformed to vent into Karman vortex sheet. Fact that flow enters vent with axial momentum invalidates boundary condition of Culick analysis for flow turning gain; 'correct' boundary condition leads to null vent gain. Experimental facts consistent with proof that in formal one-dimensional flow vent gain violates second law of thermodynamics. Logical and consistent way to reduce solid rocket data when pressure-time history is not neutral was derived. Since current techniques are not self-consistent in this situation, these results open door to reclamation of performance data heretofore rejected. (Author).

Author :
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Page : 964 pages
File Size : 21,38 MB
Release : 1988
Category : Aeronautics
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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Author : Vasily B. Novozhilov
Publisher : John Wiley & Sons
Page : 352 pages
File Size : 39,28 MB
Release : 2020-08-21
Category : Technology & Engineering
ISBN : 1119525640

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Despite significant developments and widespread theoretical and practical interest in the area of Solid-Propellant Nonsteady Combustion for the last fifty years, a comprehensive and authoritative text on the subject has not been available. Theory of Solid-Propellant Nonsteady Combustion fills this gap by summarizing theoretical approaches to the problem within the framework of the Zeldovich-Novozhilov (ZN-) theory. This book contains equations governing unsteady combustion and applies them systematically to a wide range of problems of practical interest. Theory conclusions are validated, as much as possible, against available experimental data. Theory of Solid-Propellant Nonsteady Combustion provides an accurate up-to-date account and perspectives on the subject and is also accompanied by a website hosting solutions to problems in the book.

Author : J. P. Renie
Publisher :
Page : 203 pages
File Size : 16,4 MB
Release : 1981
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In this report, the theoretical, steady state combustion model, the Petite Ensemble Model (PEM), is described in detail. The PEM is based upon a combination of a unique statistical treatment of the burning propellant surface and a comprehensive multiple flame type, physio-chemical combustion model. Due to this statistical treatment, the PEM can account for both oxidizer particle size and oxidizer particle size distribution effects on burning rate behavior; an unique feature of this model. The effects on propellant burning rate behavior due to the inclusion of aluminum particles have been taken into account within this version of the PEM, as have any possible effects caused by the presence of a crossflow velocity above the propellant surface (erosive burning). The PEM is capable of modeling the burning behavior of AP-based/hydrocarbon binder, composite solid propellants. Propellant additives such as aluminum oxide, zirconium carbide and graphite, as well as aluminum, can also be incorporated in the propellant formulations modeled by the PEM. This report presents the results obtained by applying a small perturbation analysis to the equations representing the steady state PEM (including aluminum and erosive burning effects). Performing such an analysis yields nonsteady state models of both the pressure coupled response and the velocity pressure coupled response of composite solid propellants. Other historical pressure coupled response models such as the Dension and Baum mode, the Cohen model, and the Zeldovich/Novozhilov model are also briefly described. Finally, a second velocity coupled response model based on the Zeldovich/Novozhilov methodology coupled to the erosive burning PEM is presented. (Author).

Author : Merrill K. King
Publisher :
Page : 14 pages
File Size : 24,47 MB
Release : 1978
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A model for prediction of burning rate-pressure-crossflow velocity relationships for non-metalized composite propellants containing unimodal oxidizer, given only composition and oxidizer particle size, has been developed. This model embodies many of the concepts used in the Beckstead-Derr-Price model, but contains major modifications, including a postulated columnar diffusion flame bending mechanism for erosive burning. The major part of this paper is devoted to description and discussion of these modifications and to model development. Preliminary predictions of burning rate at various pressures and crossflow velocities have been made for a series of three 73/27 ammonium perchlorate (AP)/hydroxy-terminated-polybutadiene (HTPB) formulations, with oxidizer particle diameters of 5, 20, and 200 microns, and compared with data for these formulations. With optimization of three 'free constants' appearing in the model, it is found to give excellent agreement with no-crossflow burning rate data over the entire range of pressures and particle sizes studied. In all cases, however the predicted sensitivity of burning rate to crossflow velocity is somewhat less than observed experimentally. (Author).