2,029 research outputs found
Effect of reaction control system jet-flow field interactions on a 0.015 scale model space shuttle orbiter aerodynamic characteristics
The effects of the reaction control system (RCS) jet-flow field interactions on the space shuttle orbiter system during entry are discussed. The primary objective of the test program was to obtain data for the shuttle orbiter configuration to determine control amplification factors resulting from jet interaction between the RCS plumes and the external flow over the vehicle. A secondary objective was to provide data for comparison and improvement of analytic jet interaction prediction techniques. The test program was divided into two phases; (1) force and moment measurements were made with and without RCS blowing, investigating environment parameters (R sub e, Alpha, Beta), RCS plume parameters (Jet pressure ratio, momentum ratio and thrust level), and geometry parameters (RCS pod locations) on the orbiter model, (2) oil flow visualization tests were conducted on a dummy balance at the end of the test
Calculation of AGARD Wing 445.6 Flutter Using Navier-Stokes Aerodynamics
An unsteady, 3D, implicit upwind Euler/Navier-Stokes algorithm is here used to compute the flutter characteristics of Wing 445.6, the AGARD standard aeroelastic configuration for dynamic response, with a view to the discrepancy between Euler characteristics and experimental data. Attention is given to effects of fluid viscosity, structural damping, and number of structural model nodes. The flutter characteristics of the wing are determined using these unsteady generalized aerodynamic forces in a traditional V-g analysis. The V-g analysis indicates that fluid viscosity has a significant effect on the supersonic flutter boundary for this wing
Ternary algebras and groups
We construct explicitly groups associated to specific ternary algebras which
extend the Lie (super)algebras (called Lie algebras of order three). It turns
out that the natural variables which appear in this construction are variables
which generate the three-exterior algebra. An explicit matrix representation of
a group associated to a peculiar Lie algebra of order three is constructed
considering matrices with entry which belong to the three exterior algebra.Comment: 11 pages contribution to the 5th International Symposium on Quantum
Theory and Symmetries (QTS5
Goals and Distractions: Explanations of Early Attrition from Traditional University Freshmen
This grounded theory study was designed to investigate the factors that influenced 20 traditional university freshmen to withdraw prior to the end of their first year at two Midwestern universities. A two-hour audio- taped interview was conducted with each of the participants, and the grounded theory method was utilized to analyze the interview data. Eighteen of the twenty participants had strong high school GPAs and ACT scores, and would not have been identified as being at-risk for attrition. The grounded theory that emerged from the participants\u27 data indicated that an absence of clear educational goals, as well as individual and institutional distractions, interacted to contribute to the participants\u27 withdrawal from their universities
The Polish Church Examines Its Conscience
Focuses on the conference entitled `Examination of Conscience: the Polish church Confronts Anti-Semitism, 1989-1999,\u27 held on January 20 at the Loyola Marymount University in Los Angeles, California
Poincar\'e and sl(2) algebras of order 3
In this paper we initiate a general classification for Lie algebras of order
3 and we give all Lie algebras of order 3 based on
and the Poincar\'e algebra in four-dimensions. We then
set the basis of the theory of the deformations (in the Gerstenhaber sense) and
contractions for Lie algebras of order 3.Comment: Title and presentation change
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