Generalized Simulation Technique for Turbojet Engine System Analysis
Generalized Simulation Technique for Turbojet Engine System Analysis

Author: Kurt Seldner

Publisher:

Published: 1972

Total Pages: 76

ISBN-13:

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A nonlinear analog simulation of a turbojet engine was developed. The purpose of the study was to establish simulation techniques applicable to propulsion system dynamics and controls research. A schematic model was derived from a physical description of a J85-13 turbojet engine. Basic conservation equations were applied to each component along with their individual performance characteristics to derive a mathematical representation. The simulation was mechanized on an analog computer. The simulation was verified in both steady-state and dynamic modes by comparing analytical results with experimental data obtained from tests performed at the Lewis Research Center with a J85-13 engine. In addition, comparison was also made with performance data obtained from the engine manufacturer. The comparisons established the validity of the simulation technique.

Generalized Tables of Corrections to Thermodynamic Properties for Nonpolar Gases
Generalized Tables of Corrections to Thermodynamic Properties for Nonpolar Gases

Author: Harold William Woolley

Publisher:

Published: 1956

Total Pages: 670

ISBN-13:

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Tables are presented based on the Lennard-Jones 6-12 potential for nonpolar molecules to be used in the representation of second and third virial coefficients and equation-of-state corrections for enthalpy, entropy, specific heats at constant volume and at constant pressure, the ratio of specific heats, the isentropic expansion coefficient, and the velocity of sound. The treatment for effects involving three molecules jointly uses an empirical adjustment of the Lennard-Jones force parameters within a cluster of three independently of the value for an isolated pair. A graphical correlation of ratios of these parameters with the critical constants is also shown which permits better estimates for compact nonpolar molecules with known critical constants but with limited data of state.

Some Linear Dynamics of Two-spool Turbojet Engines
Some Linear Dynamics of Two-spool Turbojet Engines

Author: David Novik

Publisher:

Published: 1956

Total Pages: 35

ISBN-13:

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General equations for the linear responses of inner- and outer-spool speed to change in turbine-inlet temperature and exhaust-nozzle area are derived and evaluated from hypothetical two-spool-engine characteristics at design speed. The resultant equations of response are corrobated with experimental data. At design speed the response of inner-spool speed to turbine-inlet temperature approximated a first-order lag specified by the time constant of the inner spool. The outer-spool speed to turbine-inlet temperature was found experimentally to be identical with the response of inner-spook speed, in that it approximated a first-order lag specified by the inner-spool time constnat. The analytically derived response of outer-spool speed to turbine-inlet temperature was a lead second-order lag that culd result in the experimentally determined response by cancellation of terms in the response equation. With respect to changes in exhaust-nozzle area, the design-speed response of the outer-spool speed approximated a first-order lag specified by the outer-spool speed approximated a firs-order lag specified by the outer-spool time constant, whereas the inner-spool speed response approximated a second-order lag, but of negligible amplitude.

Turbomachinery Flow Physics and Dynamic Performance
Turbomachinery Flow Physics and Dynamic Performance

Author: Meinhard T. Schobeiri

Publisher: Springer Science & Business Media

Published: 2012-05-01

Total Pages: 738

ISBN-13: 3642246753

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With this second revised and extended edition, the readers have a solid source of information for designing state-of-the art turbomachinery components and systems at hand. Based on fundamental principles of turbomachinery thermo-fluid mechanics, numerous CFD based calculation methods are being developed to simulate the complex 3-dimensional, highly unsteady turbulent flow within turbine or compressor stages. The objective of this book is to present the fundamental principles of turbomachinery fluid-thermodynamic design process of turbine and compressor components, power generation and aircraft gas turbines in a unified and compact manner. The book provides senior undergraduate students, graduate students and engineers in the turbomachinery industry with a solid background of turbomachinery flow physics and performance fundamentals that are essential for understanding turbomachinery performance and flow complexes. While maintaining the unifying character of the book structure in this second revised and extended edition all chapters have undergone a rigorous update and enhancement. Accounting for the need of the turbomachinery community, three chapters have been added, that deal with computationally relevant aspects of turbomachinery design such as boundary layer transition, turbulence and boundary layer.