Download or read book Solid propellant Combustion Instability and the Role of Velocity Coupling written by Louis A. Povinelli and published by . This book was released on 1969 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pressure and velocity coupling effects on combustion stability in solid propellant burning.

Download or read book Solid propellant Combustion Instability and the Role of Velocity Coupling written by Louis A. Povinelli and published by . This book was released on 1969 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Velocity Coupling Combustion Instability written by Merrill W. Beckstead and published by . This book was released on 1973 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the program were: To develop an understanding of the role of velocity-coupled combustion response in solid propellant combustion instability, to evaluate various methods for quantitatively measuring this response, and to select the most appropriate method for future development and evaluation. The study was divided into three phases: Supporting analyses to provide direction for the experimental phases; a phenomenological study to determine relative effects of propellant combustion in an oscillatory environment; and the evaluation of test techniques to find a quantitative tool for characterizing velocity coupling. (Modified author abstract).

Download or read book Coupling Between Velocity Oscillations and Solid Propellant Combustion written by R. S. Brown and published by . This book was released on 1984 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies are being conducted to define and characterize the basic fluid mechanics and heat transfer mechanism controlling the coupling between acoustic and radial profiles of the mean and oscillatory velocity are being measured at several axial stations in a cold flow rocket simulator. Recent studies have concentrated on measuring the structure of the acoustic waves and how this structure relates to the oscillatory heat flux data reported earlier. In particular, the radial profiles of the magnitude and phase (relative to the head end acoustic pressure) of the acoustic velocity have been measured at several axial stations. At low acoustic pressures (i.e., 0.05%) the acoustic waves extend across the entire cross-section in the region upstream of the transition in the mean velocity profile. Nonplaner and nonlinear behavior is also observed in the near surface regions. Downstream of the velocity transition, the acoustic waves do not penetrate through the near wall turbulence. At higher acoustic pressures (i.e., 0.4%) the upstream nonlinearities increase in magnitude and extend across the entire port. Downstream of the velocity transition the core nonlinearities decay while the linear component penetrates through the turbulence to the wall. Originator-supplied keywords include: Velocity coupling; and Combustion instability.

Download or read book Nonlinear Combustion Instability in Solid Rocket Motors A Numerical Study of Longitudinal Oscillations with Pressure and Velocity Coupling written by Joseph D. Baum and published by . This book was released on 1982 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: An existing nonlinear instability model has been extended and improved to allow it to more realistically treat the longitudinal shock wave type of combustion instability frequently encountered in tactical solid rocket motors. Results obtained utilizing this model to investigate limiting amplitude and velocity coupling phenomena in solid rocket motors are presented. An advanced finite difference integration technique capable of accurately describing shocks and contact discontinuities has been incorporated into the computer program, as well as an improved heat conduction solution, an heuristic velocity coupling model, and a spectral analysis capability. Solutions of wave propagation and shock formation and propagation in a variable area duct and a solid propellant rocket motor are presented; as are a number of solutions demonstrating that limiting amplitude is independent of the characteristics of the initial disturbance. Results of a preliminary study of nonlinear velocity modulated limit cycles are presented, as are results that demonstrate the primarily traveling wave nature of nonlinear wave propagation in solid rocket motors, and the complexity of the phase relationships between pressure, burning rate, and velocity oscillations are presented. Finally, the effect of a threshold velocity on non-linear velocity coupled instability was explored, and some of the results are also presented. (Author).

Download or read book Coupling Between Acoustic Velocity Oscillations and Solid Propellant Combustion written by R. S. Brown and published by . This book was released on 1986 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fluid mechanics of the coupling between acoustic waves and the solid propellant combustion have been studied in a cold flow simulation of a solid propellant rocket motor. The axial variation of the oscillatory heat flux shows substantial deviations from the behavior expected from both the linear and nonlinear heuristic models of velocity coupling that are currently used in combustion stability analyses. Keywords: solid propellants, combustion, acoustics, instability.

Download or read book Development of a Computerized Analysis for Solid Propellant Combustion Instability with Turbulence written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multi-dimensional numerical model has been developed for the unsteady state oscillatory combustion of solid propellants subject to acoustic pressure disturbances. Including the gas phase unsteady effects, the assumption of uniform pressure across the flame zone, which has been conventionally used, is relaxed so that a higher frequency response in the long flame of a double-base propellant can be calculated. The formulation is based on a premixed, laminar flame with a one-step overall chemical reaction and the Arrhenius law of decomposition with no condensed phase reaction. In a given geometry, the Galerkin finite element solution shows the strong resonance and damping effect at the lower frequencies, similar to the result of Denison and Baum. Extended studies deal with the higher frequency region where the pressure varies in the flame thickness. The nonlinear system behavior is investigated by carrying out the second order expansion in wave amplitude when the acoustic pressure oscillations are finite in amplitude. Offset in the burning rate shows a negative sign in the whole frequency region considered, and it verifies the experimental results of Price. Finally, the velocity coupling in the two-dimensional model is discussed. Chung, T. J. and Park, O. Y. Unspecified Center NAG8-627...

Download or read book Multi Dimensional Combustion Instability Analysis of Solid Propellant Rocket Motors written by T. J. Chung and published by . This book was released on 1985 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical models are developed for the multi-dimensional combustion instability analysis of solid propellant rocket motors. This research was motivated by the need for improvement of the current practice in combusiton instability analysis. For example, the burning rates and response functions are affected by the extremely complex flowfield. The flow is three-dimensional or at least two-dimensional in axisymmetric geometries; vortex motions and turbulent flows must be adequately calculated; the coupling mechanism of acoustic and hydrodynamic wave oscillations and particle damping should be clarified. These flowfield phenomena, after all, are originated from the flame zone activities - oscillatory behavior of all field variables such as temperature, velocity, pressure, density of the gas, and fuel fractions. The response functions, which serve as boundary conditions for the flowfield can be calculated from the first and second order perturbation eigenvalue analyses of the flame zone governing equations. The effect of velocity coupling appears, naturally, in the second order (nonlinear) solutions. All calculations are carried out using the finite element method. Some of the findings are summarized.

Download or read book Nonsteady Burning and Combustion Stability of Solid Propellants written by Martin Summerfield and published by AIAA. This book was released on 1992 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Propellant Rocket Combustion Instability written by David T. Harrje and published by . This book was released on 1972 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt: The solution of problems of combustion instability for more effective communication between the various workers in this field is considered. The extent of combustion instability problems in liquid propellant rocket engines and recommendations for their solution are discussed. The most significant developments, both theoretical and experimental, are presented, with emphasis on fundamental principles and relationships between alternative approaches.

Download or read book NASA Technical Note written by and published by . This book was released on 1969 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Propellant Rocket Combustion Instability written by and published by . This book was released on 1972 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Analysis of Nonlinear Longitudinal Combustion Instability in Metalized Propellant Solid Rocket Motors Volume I Analysis and Results written by and published by . This book was released on 1972 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present report is part of a two volume set which describes a nonlinear solid rocket motor instability analysis and computer program. The primary objective of the current effort was the development and solution of a nonlinear analytical longitudinal instability model, which would allow all of the various governing phenomena to be accounted for in a coupled manner. The two primary elements of the current instability analysis are a method of characteristics solution of the two phase flow in the combustion chamber of the motor, and a coupled calculation of a transient burning rate. It is based on an extension of the most popular, linear, harmonic combustion response model. The current method allows the calculation of propellant burning response to a pressure disturbance of arbitrary waveform, for all time, including the period immediately following the initiation of the disturbance. The analysis also includes a model for velocity coupled response. The nonlinear effects of velocity coupling on the growth of pressure waves in a combustion chamber can be computed.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combustion Instabilities In Solid Propellant Rocket Motors written by and published by . This book was released on 2004 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Magnetic Flowmeter Measurement of Solid Propellant Pressure coupled and Velocity coupled Responses written by and published by . This book was released on 1988 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents a continuation of previous work with the pressure-coupled magnetic flowmeter burner to extend its measurements capacity to include a wider frequency spectrum and variety of propellants. The results obtained in this experimental program extend the operable frequency range of a magnetic flowmeter burner to a lower limit of 200 Hz, well into the range where intermediate frequency instabilities occur. Six formulations of AP-HTPB composite propellant (including one moderately aluminized composition) were successfully tested, and their pressure-coupled response functions measured over the burner's operating frequency range. This research also attempted to directly measure a high-frequency solid propellant velocity-coupled admittance. The velocity-coupled admittance was defined in this research as the complex ratio of the oscillatory mass-flow velocity generated from the surface of a burning propellant to the oscillatory cross-flow velocity above the surface. These oscillatory velocities were measured simultaneously inside a rectangular slab-burning combustion chamber with a magnetic flowmeter. The high-frequency cross flows were created by spinning a spur gear over the sonic nozzle exhaust of the combustion chamber, thus exciting acoustic modes inside the chamber. The admittance results show similar trends under the same burning conditions, and approximate values could be estimated. Keywords: Solid rocket propellants, Combustion stability, Acoustic admittance.

Download or read book Solid Propellant Combustion Instability Oscillatory Burning of Solid Rocket Propellants written by R. H. Woodward Waesche and published by . This book was released on 1965 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: The occurrence of combustion instability in solid propellant rocket motors; The morphology of combustion oscillations; Theories of elemental processes in combustion instability - a literature survey; A detailed discussion of pressure coupling with the surface flame zone; Experimental studies on the nature of the pressure - surface flame coupling; Consideration of possible experiments to measure acoustic admittance; Acoustic admittance and entropy waves; Experimental apparatus; Experimental results; Damping mechanism studies; Conclusions and future experiments.