SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Unstable liquid propellant rocket engine nonlinear behavior, considering stability of cylindrical combustor with distributed steady state combustion process and multiorifice quasi-steady nozzle
Classes of instability behavior are reviewed and related to theory and to aspects of the combustion process. Experimental methods for small-scale testing of stability characteristics of propellants are described and typical results are presented.
Program for simulation of gas motion illustrates the effects of some of the variables on the combustion chambers of liquid propellant rocket engines. The program is based on numerically integrating the laws of inviscid fluid dynamics by two-step Lax-Wendroff technique.
Computer program contains mathematical model which provides relationship between engine gas dynamics and combustion processes. Mathematically simulated explosions initiate gas disturbances. Design methods for damping disturbances can be studied to prevent future engine shutdown or destruction.
The development of analytical techniques and numerical methods for the prediction of the stability behavior of liquid propellant rocket combustors is discussed. The studies involved nonlinear wave propagation effects and nonlinear combustion zone, liner, and nozzle responses. A second primary extension of the basic theory was directed at the inclusion of the effects of injector face baffles. Attention was restricted to the linear (small amplitude) problem, finite Mach numbers, three dimensional oscillations, and distributed combustion effects.
The development is discussed of analytical techniques and numerical methods for the prediction of the stability behavior of liquid propellant rocket combustors with partial length acoustic liners, injector face baffles, and nonlinear combustion responses. Three primary objectives included: (1) extension of the Green's Function integral-iteration technique previously developed so that nonlinear three dimensional wave propagation effects could be included in stability predictions; (2) development of an analytical technique and a computer program for the prediction of the damping effects caused by injector face baffles; and (3) inclusion of a nonlinear, wave distortation dependent, combustion response model in the global stability analysis and determination of its effect on combustor stability.
No abstract available
Computerized simulation of high frequency instability in gas in liquid propellant rocket engines
Two phase detonations in liquid-gas system of liquid rocket motor
Predicting nonlinear behavior of unstable liquid propellant rocket motors by Galerkin method
Water cooled pressure probes for measuring rocket chamber HF pressure variations
User manual for computer programs to determine high frequency instability in baffled annular liquid propellant rocket engines - Vol. 2
Explore the source record for details and available documents.
A bipropellant stability model is presented in which feed system inertance and capacitance are treated along with injection pressure drop and distinctly different propellant time lags. The model is essentially an extension of Crocco's and Cheng's monopropellant model to the bipropellant case assuming that the feed system inertance and capacitance along with the resistance are located at the injector. The neutral stability boundaries are computed in terms of these parameters to demonstrate the interaction among them.
At the present time, there are three general analytical techniques available to study problems of unsteady motions in rocket motors: linear stability analysis; approximate nonlinear analysis, founded on examining the behavior of coupled normal modes; and numerical calculations based on the conservation equations for one-dimensional flows. The last two yield the linear results as a limit. It is the main purpose of this paper to check the accuracy of the approximate analysis against the numerical analysis for some special cases. The results provide some justification for using the approximate analysis to study three-dimensional problems.
Explore the source record for details and available documents.
Previously cited in issue 06, p. 829, Accession no. A82-17746
A model is developed on using quasi-steady state equations for the injection, atomization, and vaporization processes that consider the instantaneous local pressures, temperatures, density, and gas velocity vector associated with a 3-D wave. The coupled sets of equations are solved to determine frequency and growth rate of the oscillations as a function of wave amplitude. Calculated results are used to explain the observed instabilities in a 40 Klb LOX/Methane combustor.