Journal ArticleDOI

# Einfluß der Geometrie auf die Wärmeleitung in Kühlkanälen einer Flüssigkeits-Rakete

01 Dec 1980-Vol. 14, Iss: 4, pp 245-251

TL;DR: In this paper, einige typische Ergebnisse fur zweidimensionale, stationare warmeleitung in Kuhlkanalen with der Randbedingung dritter Art, werden kreisformige, rechtwinkelige, trapezformige and gleichschenkelig-dreieckige Querschnitte with gerundeten Ecken betrachtet.

AbstractDie Arbeit zeigt einige typische Ergebnisse fur zweidimensionale, stationare Warmeleitung in Kuhlkanalen mit der Randbedingung dritter Art, wie sie ublicherweise bei gekuhlten Flussigkeitsraketen auftreten. Es werden kreisformige, rechtwinkelige, trapezformige und gleichschenkelig-dreieckige Querschnitte mit gerundeten Ecken betrachtet. Die Losungsmethode fust auf dem Rand-Kollokationsverfahren der linearen Anpassung mit Hilfe des Prinzips der kleinsten Fehlerquadrate unter Verwendung von Householder-Reflexionen.

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TL;DR: In this article, a physics-first and design-oriented text describes and explains the underlying flow and heat transfer theory of secondary air systems and provides the reader with robust solution techniques, state-of-the-art three dimensional computational fluid dynamics (CFD) methodologies, and examples of compressible flow network modeling.
Abstract: This long-awaited, physics-first and design-oriented text describes and explains the underlying flow and heat transfer theory of secondary air systems. An applications-oriented focus throughout the book provides the reader with robust solution techniques, state-of-the-art three-dimensional computational fluid dynamics (CFD) methodologies, and examples of compressible flow network modeling. It clearly explains elusive concepts of windage, non-isentropic generalized vortex, Ekman boundary layer, rotor disk pumping, and centrifugally-driven buoyant convection associated with gas turbine secondary flow systems featuring rotation. The book employs physics-based, design-oriented methodology to compute windage and swirl distributions in a complex rotor cavity formed by surfaces with arbitrary rotation, counter-rotation, and no rotation. This text will be a valuable tool for aircraft engine and industrial gas turbine design engineers as well as graduate students enrolled in advanced special topics courses.

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Journal ArticleDOI
TL;DR: This paper considers stable numerical methods for handling linear least squares problems that frequently involve large quantities of data, and they are ill-conditioned by their very nature.
Abstract: A common problem in a Computer Laboratory is that of finding linear least squares solutions. These problems arise in a variety of areas and in a variety of contexts. Linear least squares problems are particularly difficult to solve because they frequently involve large quantities of data, and they are ill-conditioned by their very nature. In this paper, we shall consider stable numerical methods for handling these problems. Our basic tool is a matrix decomposition based on orthogonal Householder transformations.

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TL;DR: An implementation of Stiefel's exchange algorithm for determining a Chebyshev solution to an overdetermined system of linear equations is presented, that uses Gaussian LU decomposition with row interchanges.
Abstract: An implementation of Stiefel's exchange algorithm for determining a Chebyshev solution to an overdetermined system of linear equations is presented, that uses Gaussian LU decomposition with row interchanges. The implementation is computationally more stable than those usually given in the literature. A generalization of Stiefel's algorithm is developed which permits the occasional exchange of two equations simultaneously.

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