Calculation of Three-dimensional Boundary Layers on Bodies at Incidence

Calculation of Three-dimensional Boundary Layers on Bodies at Incidence PDF Author: V. C. Patel
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 32

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Book Description
Three-dimensional thin boundary-layer equations for laminar and turbulent flows are solved by two different numerical schemes. The methods are applied to the flow over bodies of revolution at incidence and the results are compared with the available experimental data in order to study the range of validity of the classical boundary-layer approximations in regions of increasing circumferential gradients and flow reversal associated with the early stages of a free-vortex type of separation. Comparison with the DFVLR 6:1 spheroid data of Meier et al and the 4:1 combination-body data of Ramaprian, Patel and Choi indicate that the methods perform well in regions where the boundary layer remains thin but the predictions deteriorate as the boundary layer thickens. The results point out the need for the development of methods of handle thick boundary layers and viscous-inviscid interactions. (Author).

Calculation of Three-dimensional Boundary Layers on Bodies at Incidence

Calculation of Three-dimensional Boundary Layers on Bodies at Incidence PDF Author: V. C. Patel
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 32

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Book Description
Three-dimensional thin boundary-layer equations for laminar and turbulent flows are solved by two different numerical schemes. The methods are applied to the flow over bodies of revolution at incidence and the results are compared with the available experimental data in order to study the range of validity of the classical boundary-layer approximations in regions of increasing circumferential gradients and flow reversal associated with the early stages of a free-vortex type of separation. Comparison with the DFVLR 6:1 spheroid data of Meier et al and the 4:1 combination-body data of Ramaprian, Patel and Choi indicate that the methods perform well in regions where the boundary layer remains thin but the predictions deteriorate as the boundary layer thickens. The results point out the need for the development of methods of handle thick boundary layers and viscous-inviscid interactions. (Author).

Calculation of Three-Dimensional Boundary Layers on Bodies of Revolution at Incidence

Calculation of Three-Dimensional Boundary Layers on Bodies of Revolution at Incidence PDF Author: Tuncer Cebeci
Publisher:
ISBN:
Category :
Languages : en
Pages : 175

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Book Description
The laminar three-dimensional boundary layer on a body of revolution at incidence is investigated using two methods. In the first, the standard equations are solved numerically using the Keller box scheme. The second method solves a set of equations, which contain the standard equations, derived from the assumption that crossflow gradients may be important. Since these equations are elliptic in the crossflow plane, an ADI procedure is used for their solution. In regions where there is no crossflow reversal, both methods yield the same results. However, differences appear in regions where the crossflow is not unidirectional. Reasons for this discrepancy are discussed and the relative merits of each procedure identified. (Author).

Three-Dimensional Laminar Boundary Layer Over Body of Revolution at Incidence. Part VI. General Methods and Results of the Case of High Incidence

Three-Dimensional Laminar Boundary Layer Over Body of Revolution at Incidence. Part VI. General Methods and Results of the Case of High Incidence PDF Author: K. C. Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 54

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Book Description
The report presents general methods for calculating three-dimensional laminar boundary layers over inclined blunt bodies (not necessarily bodies of revolution). Complete incompressible results for a prolate spheroid at 30 degrees incidence are presented, and the computational procedures are described. The rule of the zone of dependence was observed. The results display for the first time the boundary layer structure over a non-spherical and non-conical blunt body in all details, and confirm the open-type of separation proposed earlier. (Author).

Three-Dimensional Boundary Layers on Bodies of Revolution at Incidence

Three-Dimensional Boundary Layers on Bodies of Revolution at Incidence PDF Author: V. C. Patel
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

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Book Description
This report summarizes the objectives and accomplishments of an experimental and theoretical investigation of the boundary layer development on bodies of revolution at incidence. The results of the flow visualization studies in laminar flow, detailed measurements in a turbulent boundary layer, and calculations of laminar as well as turbulent boundary layers using two different numerical schemes and turbulence models are reviewed to emphasize the important characteristics of separation in three dimensions.

Three-Dimensional Laminar Boundary Layer Over Body of Revolution at Incidence. Part IX. Difference Method and Documentation of Program 'BLIND3'.

Three-Dimensional Laminar Boundary Layer Over Body of Revolution at Incidence. Part IX. Difference Method and Documentation of Program 'BLIND3'. PDF Author: K. C. Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 202

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Book Description
The report documents the program 'BLIND3' and its associated difference methods. BLIND3 stands for Boundary Layer in 3 Dimensions. This program is for calculating genuine three-dimensional, incompressible, laminar boundary layer over a blunt-body at incidence. The whole calculation consists of the following five parts: inviscid calculations from known inviscid solution, stagnation-point boundary layer, symmetry-plane boundary layer, nose region boundary layer, and main body boundary layer. This program has been written in FORTRAN 5 language, and used for a UNIVAC 1108 computer in batch mode and under Exec. 8 system. It has been employed to obtain complete boundary layer solutions for a prolate spheroid at low and high incidences.

Computational Implications of the Zone of Dependence Concept for Three-dimensional Boundary Layers on a Spinning Body

Computational Implications of the Zone of Dependence Concept for Three-dimensional Boundary Layers on a Spinning Body PDF Author: Clarence W. Kitchens (Jr.)
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 70

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Book Description
The properties of the three-dimensional boundary-layer equations and the influence of these properties on numerical solutions are examined. The three-dimensional boundary-layer equations are parabolic, but they possess a secondary hyperbolic-like, property. This hyperbolic property leads to the zone of dependence concept. It is shown that the zone of dependence concept plays an important role in obtaining accurate numerical solutions for three-dimensional boundary-layer problems; it is especially important for calculating the boundary layer on a spinning body at incidence. A simple flow field which simulates the essential features of this problem and is an exact solution of the three-dimensional boundary-layer equations is constructed.

The Three-dimensional Boundary Layer

The Three-dimensional Boundary Layer PDF Author: Naval Ordnance Test Station (Inyokern, Calif.)
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 42

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Book Description


Computation of Three-Dimensional Complex Flows

Computation of Three-Dimensional Complex Flows PDF Author: Michel Deville
Publisher: Springer Science & Business Media
ISBN: 3322898385
Category : Technology & Engineering
Languages : en
Pages : 406

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Book Description
Der Sammelband enthält Beiträge einer Tagung über die Simulation von dreidimensionalen Flüssigkeiten. Sie geben einen Überblick über den Stand des Wissens auf dem Gebiet der numerischen Simulation der Turbulenz, angewandt auf eine weite Spanne von Problemen wie Aerodynamik, Nicht-Newtonsche Flüssigkeiten, Konvektion.This volume contains the material presented at the IMACS-COST Conference on CFD, Three-Dimensional Complex Flows, held in Lausanne (Switzerland), September 13 - 15, 1995. It gives an overview of the current state of numerical simulation and turbulence modelling applied to a wide range of fluid flow problems such as an example aerodynamics, non-Newtonian flows, transition, thermal convection.

Calculation of the Boundary-layer Flow in the Windward Symmetry Plane of a Spherically Blunted Axisymmetric Body at Angle of Attack, Including Streamline-swallowing Effects

Calculation of the Boundary-layer Flow in the Windward Symmetry Plane of a Spherically Blunted Axisymmetric Body at Angle of Attack, Including Streamline-swallowing Effects PDF Author: Arloe W. Mayne (Jr.)
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 60

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Book Description
Three-dimensional compressible boundary-layer equations are particularized to the windward symmetry plane of a spherically blunted axisymmetric body at incidence under hypersonic conditions. Through the use eddy transport and streamwise intermittency both transitional and fully turbulent boundary layers may be treated. A scheme is presented for determining the outer-edge boundary conditions based on a mass flow balance treatment of the boundary-layer entrainment of the inviscid flow. A finite-difference technique is described for solving the set of partial differential equation governing the boundary-layer flow, and for treating the streamline-swallowing phenomenon.

The Role of the Zone of Dependence Concept in Three-dimensional Boundary-layer Calculations

The Role of the Zone of Dependence Concept in Three-dimensional Boundary-layer Calculations PDF Author: Clarence W. Kitchens (Jr.)
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 48

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Book Description
The subject is studied for the general initial-value problem which arises in several applications; e.g., a spinning body at incidence. An exact solution which simulates the essential features of the boundary layer on such a body is used as a test case. The zone of dependence concept places a restriction on the local mesh aspect ratio that may be used. Results from four finite-difference schemes are compared against the exact solution for various wall speeds and mesh aspect ratios. Error growth occurs when the zone of dependence rule is not satisfied. The sensitivity and manner of error growth for the four schemes are different; two of them are relatively insensitive. From stability analyses it is shown that the concepts of stability and zone of dependence are not the same. Our numerical experiments partly contradict the stability analyses.