Calculation of transitional boundary-layer flows.

AIAA Journal ◽  
1973 ◽  
Vol 11 (4) ◽  
pp. 554-556 ◽  
Author(s):  
D. M. BUSHNELL ◽  
D. W. ALSTON
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flows ◽  
Transitional Boundary Layer

k-e Model for Predicting Transitional Boundary-Layer Flows Under Zero-Pressure Gradient

AIAA Journal ◽  
2001 ◽  
Vol 39 (9) ◽  
pp. 1699-1705 ◽  
Author(s):  
Seong Gu Baek ◽  
Myung Kyoon Chung ◽  
Hyo Jae Lim
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Boundary Layer Flows ◽  
Transitional Boundary Layer

Prediction of laminar, transitional and turbulent flow regimes, based on three-equation k-ω turbulence model

2008 ◽  
Vol 112 (1134) ◽  
pp. 469-476 ◽  
Author(s):  
R. Taghavi-Zenouz ◽  
M. Salari ◽  
M. Etemadi
Keyword(s):  
Boundary Layer ◽  
Kinetic Energy ◽  
Wind Turbine ◽  
Flat Plate ◽  
Turbine Blade ◽  
Wind Turbine Blade ◽  
Freestream Turbulence ◽  
Boundary Layer Flows ◽  
Laminar Separation ◽  
Transitional Boundary Layer

Abstract A recently developed transitional model for boundary-layer flows has been examined on a flat plate and the well-known S809 wind turbine blade. Proposed numerical model tries to simulate streamwise fluctuations, induced by freestream turbulence, in pre-transitional boundary-layer flows by introducing an additional transport equation for laminar kinetic energy term. This new approach can be used for modeling of transitional flows which are exposed to both the freestream turbulence intensity and streamwise pressure gradient, which are known as the most dominant factors in occurrence of transition. Computational method of this model is based on the solution of the Reynolds averaged Navier-Stokes (RANS) equations and the eddy-viscosity concept. The model includes three transport equations of laminar kinetic energy, turbulent kinetic energy and dissipation rate frequency. The present model is capable of predicting either natural or bypass transitional mechanisms, which may occur in attached boundary-layer flows. In addition, the model can simulate transition in the separated free shear layers and the subsequent turbulent re-attachment to form a laminar separation bubble. Flat plate was exposed to different freestream turbulence intensities and streamwise pressure gradients. Wind turbine blade was examined under two different Reynolds numbers, with one of them suitable for the occurrence of laminar separation bubbles on its surfaces. To evaluate the performance of this new model in resolving transitional boundary-layer flows, final results have been compared to those obtained through application of conventional turbulence models. Comparison of final results for the flat plate and the S809 aerofoil with available experimental data show very close agreements.

Numerical Simulation of Receptivity Phenomena in Transitional Boundary-Layer Flows

AIAA Journal ◽  
1997 ◽  
Vol 35 (5) ◽  
pp. 789-795
Author(s):  
Scott H. Reitsma ◽  
Vincent P. Manno ◽  
Thomas R. Tureaud
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Boundary Layer Flows ◽  
Transitional Boundary Layer

Investigation of the Calmed Region Behind a Turbulent Spot

1997 ◽  
Vol 119 (4) ◽  
pp. 802-809 ◽  
Author(s):  
J. P. Gostelow ◽  
G. J. Walker ◽  
W. J. Solomon ◽  
G. Hong ◽  
N. Melwani
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Axial Flow ◽  
Adverse Pressure Gradient ◽  
Turbulent Spot ◽  
Boundary Layer Flows ◽  
Turbulent Spots ◽  
Controlled Diffusion ◽  
Transitional Boundary Layer ◽  
Flow Compressor

Measurements are presented of the calmed region behind triggered wave packets and turbulent spots under a controlled diffusion adverse pressure gradient in a wind tunnel. Similar measurements are also presented from the stator blades of an axial flow compressor, where turbulent spots are induced by the passing of rotor wakes. The purpose is to gain an appreciation of turbulent spot behavior under a strong adverse pressure gradient as a foundation for the more accurate modeling of spots and their environment in predictions of transitional boundary layer flows. Under an adverse pressure gradient the calmed region behind the spot is extensive; its interaction with the surrounding boundary layer is complex and is dependent on whether the surrounding natural boundary layer is laminar or turbulent. Some insights are gleaned concerning the behavior of the calmed region, which will subsequently be used in attempts to model the calmed region. Although these fundamental investigations of the calmed region have been extensive, much remains to be understood.

Entropy generation in bypass transitional boundary layer flows

2014 ◽  
Vol 26 (5) ◽  
pp. 669-680 ◽  
Author(s):  
Joseph George ◽  
Landon D. Owen ◽  
Tao Xing ◽  
Donald M. McEligot ◽  
John C. Crepeau ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Entropy Generation ◽  
Boundary Layer Flows ◽  
Transitional Boundary Layer

On nonlinearity of transitional boundary-layer flows

1995 ◽  
Vol 352 (1700) ◽  
pp. 473-482 ◽  
Keyword(s):  
Boundary Layer ◽  
Flat Plate ◽  
Experimental Studies ◽  
Nonlinear Behaviour ◽  
Boundary Layer Flows ◽  
Turbulent Spots ◽  
Laminar Separation ◽  
Short Scale ◽  
Transitional Boundary Layer ◽  
Specific Effects

This paper focuses on two specific effects concerning the nonlinearity of transitional boundary-layer flows: the generation of turbulent spots in a flat-plate flow, and the nonlinear behaviour of laminar separation bubbles associated with the short-scale instability of the separated layer. A compilation of results from several experimental studies is given.

Sign in / Sign up

Export Citation Format

Share Document