Calculation of Unsteady Transonic Flows with Mild Separation by Viscous-inviscid Interaction
Author: James T. Howlett
Publisher:
Published: 1992
Total Pages: 44
ISBN-13:
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Author: James T. Howlett
Publisher:
Published: 1992
Total Pages: 44
ISBN-13:
DOWNLOAD EBOOKAuthor: National Aeronautics and Space Adm Nasa
Publisher:
Published: 2018-11
Total Pages: 44
ISBN-13: 9781729430842
DOWNLOAD EBOOKThis paper presents a method for calculating viscous effects in two- and three-dimensional unsteady transonic flow fields. An integral boundary-layer method for turbulent viscous flow is coupled with the transonic small-disturbance potential equation in a quasi-steady manner. The viscous effects are modeled with Green's lag-entrainment equations for attached flow and an inverse boundary-layer method for flows that involve mild separation. The boundary-layer method is used stripwise to approximate three-dimensional effects. Applications are given for two-dimensional airfoils, aileron buzz, and a wing planform. Comparisons with inviscid calculations, other viscous calculation methods, and experimental data are presented. The results demonstrate that the present technique can economically and accurately calculate unsteady transonic flow fields that have viscous-inviscid interactions with mild flow separation. Howlett, James T. Langley Research Center RTOP 509-10-02-03...
Author: James T. Howlett
Publisher:
Published: 1992
Total Pages: 44
ISBN-13:
DOWNLOAD EBOOKAuthor: Laurence Byron Wigton
Publisher:
Published: 1981
Total Pages: 244
ISBN-13:
DOWNLOAD EBOOKThe aim of this thesis is to couple an inviscid two dimensional steady transonic flow calculation with a boundary layer calculation. This interaction is especially important in transonic problems since the boundary layer has a significant effect on the inviscid portion of the flow. Here, the inviscid solution is obtained by an algorithm developed for the full potential equation by Holst and Ballhaus while the attached and separated turbulent boundary layer calculations are performed by Green's lag entrainment method. Guided by a model problem suggested by Le Balleur, a viscous-inviscid coupling algorithm is developed. Theoretical analysis indicates that it coverages rapidly for attached flows ad also performs well for separated flows. These conclusions are confirmed through a series of challenging transonic calculations involving both attached and separated flows. The coupling algorithm is remarkably stable and allows computation of coupled viscous-inviscid flows within times required to perform the inviscid calculations by themselves. (Author).
Author: U. R. Muller
Publisher:
Published: 1992
Total Pages: 16
ISBN-13:
DOWNLOAD EBOOKProgress in the development towards a 30 viscous-inviscid strong interaction method for computing unsteady transonic wing flow is reported. In the current version, an ADI-technique for solving the 3D unsteady Transonic Small Perturbation Equation (TSP) has been extended by incorporating an unsteady 2D integral boundary layer method and then simultaneously solving the viscous and inviscid flow equations in a stripwise fashion.
Author: Richard G. Wilmoth
Publisher:
Published: 1977
Total Pages: 72
ISBN-13:
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Publisher:
Published: 1982
Total Pages: 78
ISBN-13:
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Publisher:
Published: 1994
Total Pages: 956
ISBN-13:
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