Author: W. D. Murphy
Publisher:
ISBN:
Category :
Languages : en
Pages : 118
Book Description
The flow field of three dimensional incompressible wall jets prototypic of thrust augmenting ejectors with large cross flow is solved using a very efficient centered-Euler scheme in an orthogonal curvilinear coordinate system. The computational model treats initial conditions with arbitrary velocity profiles at or downstream of the jet exit. An averaging approach is employed for the first few marching steps to overcome spurious numerical oscillations associated with arbitrary initial profiles. Laminar as well as turbulent wall jets are simulated. Turbulence is introduced using a two layer mixing length model appropriate to curved three-dimensional wall jets. Typical results quantifying jet spreading, jet growth, nominal separation and jet shrink effects due to cross flow are presented.
A Computational Model for Three-Dimensional Incompressible Wall Jets with Large Cross Flow
Author: W. D. Murphy
Publisher:
ISBN:
Category :
Languages : en
Pages : 118
Book Description
The flow field of three dimensional incompressible wall jets prototypic of thrust augmenting ejectors with large cross flow is solved using a very efficient centered-Euler scheme in an orthogonal curvilinear coordinate system. The computational model treats initial conditions with arbitrary velocity profiles at or downstream of the jet exit. An averaging approach is employed for the first few marching steps to overcome spurious numerical oscillations associated with arbitrary initial profiles. Laminar as well as turbulent wall jets are simulated. Turbulence is introduced using a two layer mixing length model appropriate to curved three-dimensional wall jets. Typical results quantifying jet spreading, jet growth, nominal separation and jet shrink effects due to cross flow are presented.
Publisher:
ISBN:
Category :
Languages : en
Pages : 118
Book Description
The flow field of three dimensional incompressible wall jets prototypic of thrust augmenting ejectors with large cross flow is solved using a very efficient centered-Euler scheme in an orthogonal curvilinear coordinate system. The computational model treats initial conditions with arbitrary velocity profiles at or downstream of the jet exit. An averaging approach is employed for the first few marching steps to overcome spurious numerical oscillations associated with arbitrary initial profiles. Laminar as well as turbulent wall jets are simulated. Turbulence is introduced using a two layer mixing length model appropriate to curved three-dimensional wall jets. Typical results quantifying jet spreading, jet growth, nominal separation and jet shrink effects due to cross flow are presented.
A Computational Model for Three-Dimensional Incompressible Small Cross Flow Wall Jets
Author: Norman D. Malmuth
Publisher:
ISBN:
Category :
Languages : en
Pages : 108
Book Description
A computational model based on H. Keller's box scheme has been used to characterize turbulent incompressible wall jets in the small cross flow approximation prototypic of flows over upper-surface-blown and augmenter wings. Submerged and coflowing cases are considered. An eddy viscosity model was used to simulate the effects of turbulence. Approximate models are identified for flows in which the jet height tends to zero. If the span flow is introduced through a lateral curvature term appearing in the spanwise momentum equation, the effect of the turbulent coupling on the surface pressures, and peak spanwise velocities is weak. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 108
Book Description
A computational model based on H. Keller's box scheme has been used to characterize turbulent incompressible wall jets in the small cross flow approximation prototypic of flows over upper-surface-blown and augmenter wings. Submerged and coflowing cases are considered. An eddy viscosity model was used to simulate the effects of turbulence. Approximate models are identified for flows in which the jet height tends to zero. If the span flow is introduced through a lateral curvature term appearing in the spanwise momentum equation, the effect of the turbulent coupling on the surface pressures, and peak spanwise velocities is weak. (Author).
Workshop on Thrust Augmenting Ejectors
Scientific and Technical Aerospace Reports
Technical Abstract Bulletin
NASA Conference Publication
Japanese Science and Technology
Applied Mechanics Reviews
Manipulation and Control of Jets in Crossflow
Author: Ann R. Karagozian
Publisher: Springer
ISBN: 3709127920
Category : Technology & Engineering
Languages : en
Pages : 304
Book Description
Fundamental Non-Reactive Jets in Crossflow and Other Jet Systems; Background on Modeling, Dynamical Systems, and Control; Reactive Jets in Crossflow and Multiphase Jets; Controlled Jets in Crossflow and Control via Jet Systems;
Publisher: Springer
ISBN: 3709127920
Category : Technology & Engineering
Languages : en
Pages : 304
Book Description
Fundamental Non-Reactive Jets in Crossflow and Other Jet Systems; Background on Modeling, Dynamical Systems, and Control; Reactive Jets in Crossflow and Multiphase Jets; Controlled Jets in Crossflow and Control via Jet Systems;
Computation of Incompressible, Three-Dimensional Turbulent Boundary Layers and Comparison with Experiment
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781725140189
Category :
Languages : en
Pages : 32
Book Description
Incompressible three dimensional, turbulent boundary layer (3DTBL) experiments were simulated numerically by integrating the boundary layer equations together with an algebraic eddy viscosity turbulence model. For the flow treated, the downstream portion, where the crossflow was large, was not predicted with the present computational method; the flow was significantly influenced by elliptic flow field effects. Departures from the boundary layer concept are indicated. Calculations agreed reasonably well with the mean flow development up to separation. In one experiment the normal pressure gradients were found to be neligible in regions with large skewing and allowed testing turbulence models using the boundary layer equations. The simulation of this flow compared favorably with the experimental data throughout the flow field and suggested the applicability of algebraic eddy viscosity models for 3DTBLs. Mueller, U. R. Ames Research Center NASA-TM-84230, A-8873, NAS 1.15:84230 ...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781725140189
Category :
Languages : en
Pages : 32
Book Description
Incompressible three dimensional, turbulent boundary layer (3DTBL) experiments were simulated numerically by integrating the boundary layer equations together with an algebraic eddy viscosity turbulence model. For the flow treated, the downstream portion, where the crossflow was large, was not predicted with the present computational method; the flow was significantly influenced by elliptic flow field effects. Departures from the boundary layer concept are indicated. Calculations agreed reasonably well with the mean flow development up to separation. In one experiment the normal pressure gradients were found to be neligible in regions with large skewing and allowed testing turbulence models using the boundary layer equations. The simulation of this flow compared favorably with the experimental data throughout the flow field and suggested the applicability of algebraic eddy viscosity models for 3DTBLs. Mueller, U. R. Ames Research Center NASA-TM-84230, A-8873, NAS 1.15:84230 ...