A Simple Method for Estimating Terminal Velocity Including Effect of Compressibility on Drag

A Simple Method for Estimating Terminal Velocity Including Effect of Compressibility on Drag

Author: Ralph P. Bielat

Publisher:

Published: 1945

Total Pages: 30

ISBN-13:

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Summary: A generalized drag curve that provides an estimate for the drag rise due to compressibility has been obtained for an analysis of wind-tunnel data of several airfoils, fuselages, nacelles, and windshields at speeds up to and above the wing critical speed. The airfoils analyzed had little or no sweepback and effective aspect ratios above 6.5. A chart based on the generalized drag curve is presented from which the terminal velocity of a conventional airplane that employs a wing of moderate aspect ratio and very little sweepback in a vertical dive may be rapidly estimated. In order to use the chart, the only data that need be known about the airplane are a low-speed drag coefficient, the wing critical speed, and the wing loading. The terminal velocities for three airplanes were computed in order to illustrate the use of the method and chart. Good agreement between the estimated terminal velocity and the measured flight terminal velocity was indicated for all three airplanes.


Compressibility, Turbulence and High Speed Flow

Compressibility, Turbulence and High Speed Flow

Author: Thomas B. Gatski

Publisher: Academic Press

Published: 2013-03-05

Total Pages: 343

ISBN-13: 012397318X

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Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and an extensive discussion of the various approaches used in predicting both free shear and wall bounded flows is presented. Experimental measurement techniques common to the compressible flow regime are introduced with particular emphasis on the unique challenges presented by high speed flows. Both experimental and numerical simulation work is supplied throughout to provide the reader with an overall perspective of current trends. An introduction to current techniques in compressible turbulent flow analysis An approach that enables engineers to identify and solve complex compressible flow challenges Prediction methodologies, including the Reynolds-averaged Navier Stokes (RANS) method, scale filtered methods and direct numerical simulation (DNS) Current strategies focusing on compressible flow control


Simple Method for Estimating Terminal Velocity Including Effect of Compressibility on Drag

Simple Method for Estimating Terminal Velocity Including Effect of Compressibility on Drag

Author: Langley Aeronautical Laboratory

Publisher: Hassell Street Press

Published: 2021-09-09

Total Pages: 30

ISBN-13: 9781013471421

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This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.


Synthesis of Subsonic Airplane Design

Synthesis of Subsonic Airplane Design

Author: E. Torenbeek

Publisher: Springer Science & Business Media

Published: 2013-06-29

Total Pages: 607

ISBN-13: 9401732027

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Since the education of aeronautical engineers at Delft University of Technology started in 1940 under tae inspiring leadership of Professor H.J. van der Maas, much emphasis has been placed on the design of aircraft as part of the student's curriculum. Not only is aircraft design an optional subject for thesis work, but every aeronautical student has to carry out a preliminary airplane design in the course of his study. The main purpose of this preliminary design work is to enable the student to synthesize the knowledge ob tained separately in courses on aerodynamics, aircraft performances, stability and con trol, aircraft structures, etc. The student's exercises in preliminary design have been directed through the years by a number of staff members of the Department of Aerospace Engineering in Delft. The author of this book, Mr. E. Torenbeek, has made a large contribution to this part of the study programme for many years. Not only has he acquired vast experience in teaching airplane design at university level, but he has also been deeply involved in design-oriented re search, e.g. developing rational design methods and systematizing design information. I am very pleased that this wealth of experience, methods and data is now presented in this book.


Unified Theoretical Foundations of Lift and Drag in Viscous and Compressible External Flows

Unified Theoretical Foundations of Lift and Drag in Viscous and Compressible External Flows

Author: Luo-Qin Liu

Publisher: Springer

Published: 2017-09-29

Total Pages: 168

ISBN-13: 9811062234

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This thesis analyzes aerodynamic forces in viscous and compressible external flows. It is unique, as the force theories discussed apply to fully viscous and compressible Navier-Stokes external flows, allowing them to be readily combined with computational fluid dynamics to form a profound basis of modern aerodynamics. This thesis makes three fundamental contributions to theoretical aerodynamics, presenting: (1) a universal far-field zonal structure that determines how disturbance flow quantities decay dynamically to the state of rest at infinity; (2) a universal and exact total-force formula for steady flow and its far-field asymptotics; and (3) a general near-field theory for the detailed diagnosis of all physical constituents of aerodynamic force and moment.