Numerical investigation of the fully developed turbulent flow over a moving wavy wall using k–ε turbulence model

Hafez, Khaled A.; Elsamni, Osama A.; Zakaria, Kadry

doi:10.1016/j.aej.2010.12.001

Cited by 26 publications

(15 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Different turbulence models are examined against Maaß and Schumann (1996) Direct Numerical Simulation (DNS) of turbulent flows over a wavy surface following the works done by Hafez et al (2011) and Park et al (2004) in order to select an appropriate one to be applied in the further calculation with steam condensation over wavy surface. A schematic diagram of the channel used in Maab and Schumann's DNS is shown in Fig.…”

Section: Turbulence Modelmentioning

confidence: 99%

A CFD study of wave influence on film steam condensation in the presence of non-condensable gas

Wang

Chang

Corradini

2016

Nuclear Engineering and Design

View full text Add to dashboard Cite

Section: Turbulence Modelmentioning

confidence: 99%

A CFD study of wave influence on film steam condensation in the presence of non-condensable gas

Wang

Chang

Corradini

2016

Nuclear Engineering and Design

View full text Add to dashboard Cite

“…The use of this model to result in stable calculations highlights its validity for turbulent flow even at high Reynolds number. The k‐ϵ turbulence model also estimates reasonable solutions for complex geometries due to implementation of wall function (Hafez et al, ; Rodi, ). The governing equations of the turbulent kinetic energy ( k) and dissipation rate ( ϵ ) are as follows:

ρ \frac{\partial k}{\partial t} + ρ u_{j} \frac{\partial k}{\partial x_{j}} = τ_{i j} \frac{\partial u_{i}}{\partial x_{j}} + \frac{\partial}{\partial x_{j}} [(μ + \frac{µ_{t}}{σ_{k}}) \frac{\partial k}{\partial x_{j}}] - ρ ϵ

ρ \frac{\partial ϵ}{\partial t} + ρ u_{j} \frac{\partial ϵ}{\partial x_{j}} = \frac{\partial}{\partial x_{j}} [(μ + \frac{µ_{t}}{σ_{ϵ}}) \frac{\partial ϵ}{\partial x_{j}}] + C_{ϵ 1} \frac{ϵ}{k} τ_{i j} \frac{\partial u_{i}}{\partial x_{j}} - C_{ϵ 2} ρ \frac{ϵ^{2}}{k}

where σ k and σ ϵ are the turbulent Prandtl numbers for kinetic energy and dissipation rate, respectively, while C ϵ 1 and C ϵ 2 are the first and second experimental model constants for the dissipation rate, respectively.…”

Section: Mathematical Modelingmentioning

confidence: 99%

Numerical prediction of algae cell mixing feature in raceway ponds using particle tracing methods

Ali

Cheema

Yoon

et al. 2014

Biotech & Bioengineering

View full text Add to dashboard Cite

In the present study, a novel technique, which involves numerical computation of the mixing length of algae particles in raceway ponds, was used to evaluate the mixing process. A value of mixing length that is higher than the maximum streamwise distance (MSD) of algae cells indicates that the cells experienced an adequate turbulent mixing in the pond. A coupling methodology was adapted to map the pulsating effects of a 2D paddle wheel on a 3D raceway pond in this study. The turbulent mixing was examined based on the computations of mixing length, residence time, and algae cell distribution in the pond. The results revealed that the use of particle tracing methodology is an improved approach to define the mixing phenomenon more effectively. Moreover, the algae cell distribution aided in identifying the degree of mixing in terms of mixing length and residence time.

show abstract

“…Naphon [20] found that the sharp edge of wavy plate has a significant effect on the flow structure and heat transfer enhancement. Hafez et al [21] investigated turbulent flow over a sinusoidal solid surface using two versions of standard k-ε turbulence model. Barboy et al [22] investigated the fluid flow and heat transfer in a channel with a wavy wall heated by constant heat flux.…”

Section: Introductionmentioning

confidence: 99%

Flow and heat transfer characteristics in a channel having furrowed wall based on sinusoidal wave

Wang

Gao

2015

Korean J. Chem. Eng.

View full text Add to dashboard Cite

The effect of wall geometry on the flow and heat transfer in a channel with one lower furrowed and an upper flat wall kept at a uniform temperature is investigated by large eddy simulation. Three channels, one with sinusoidal wavy surface having the ratio (amplitude to wavelength) α/λ=0.05 and the other two with furrowed surface derived from the sinusoidal curve, are considered. The numerical results show that the streamwise vortices center is located near the lower wall and vary along the streamwise on various furrow surfaces. The furrow geometry increases the pressure drag and decreases the friction drag of the furrowed surface compared with that of the smooth surface; consequently, the total drag is increased for the augment of pressure drag. As expected, the heat transfer performance has been improved. Finally, a thermal performance factor is defined to evaluate the performance of the furrowed wall.

show abstract

Numerical investigation of the fully developed turbulent flow over a moving wavy wall using k–ε turbulence model

Cited by 26 publications

References 16 publications

A CFD study of wave influence on film steam condensation in the presence of non-condensable gas

A CFD study of wave influence on film steam condensation in the presence of non-condensable gas

Numerical prediction of algae cell mixing feature in raceway ponds using particle tracing methods

Flow and heat transfer characteristics in a channel having furrowed wall based on sinusoidal wave

Contact Info

Product

Resources

About