On the Spatial Evolution of Long-Wavelength Goertler Vortices Governed by a Viscous-Inviscid Interaction

On the Spatial Evolution of Long-Wavelength Goertler Vortices Governed by a Viscous-Inviscid Interaction
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 36
Release: 2018-07-09
Genre:
ISBN: 9781722457167

The generation of long-wavelength, viscous-inviscid interactive Goertler vortices is studied in the linear regime by numerically solving the time-dependent governing equations. It is found that time-dependent surface deformations, which assume a fixed nonzero shape at large times, generate steady Goertler vortices that amplify in the downstream direction. Thus, the Goertler instability in this regime is shown to be convective in nature, contrary to the earlier findings of Ruban and Savenkov. The disturbance pattern created by steady and streamwise-elongated surface obstacles on a concave surface is examined in detail, and also contrasted with the flow pattern due to roughness elements with aspect ratio of order unity on flat surfaces. Finally, the applicability of the Briggs-Bers criterion to unstable physical systems of this type is questioned by providing a counterexample in the form of the inviscid limit of interactive Goertler vortices. Choudhari, Meelan and Hall, Philip and Streett, Craig Langley Research Center NAS1-18605; RTOP 505-90-52-01...

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports
Author:
Publisher:
Total Pages: 610
Release: 1995
Genre: Aeronautics
ISBN:

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Numerical Simulations Of Incompressible Flows

Numerical Simulations Of Incompressible Flows
Author: Mohamed M Hafez
Publisher: World Scientific
Total Pages: 708
Release: 2003-01-23
Genre: Mathematics
ISBN: 9814486396

This book consists of 37 articles dealing with simulation of incompressible flows and applications in many areas. It covers numerical methods and algorithm developments as well as applications in aeronautics and other areas. It represents the state of the art in the field.