Application of linear and non-linear low-Re k–ε models in two-dimensional predictions of convective heat transfer in passages with sudden contractions

Raisee, Mehrdad; Hejazi, S.H.

doi:10.1016/j.ijheatfluidflow.2006.07.004

Cited by 10 publications

(8 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…After the reattachment point, the flow builds up a new boundary layer as it develops along the channel with decrease in the value of Nusselt number. Agreements between the present result with experiment and also with theoretical results by Raisee et al [17] are satisfactory. It should be noted that in Ref.…”

Section: Resultssupporting

confidence: 91%

See 1 more Smart Citation

Turbulent forced convection flow adjacent to inclined forward step in a duct

Nassab

Moosavi

Sarvari

2009

International Journal of Thermal Sciences

View full text Add to dashboard Cite

Section: Resultssupporting

confidence: 91%

“…It should be noted that in Ref. [17], a linear low Re k-ε model was employed for calculating the Reynolds stresses and turbulent heat flux.…”

Section: Resultsmentioning

confidence: 99%

Turbulent forced convection flow adjacent to inclined forward step in a duct

Nassab

Moosavi

Sarvari

2009

International Journal of Thermal Sciences

View full text Add to dashboard Cite

“…According to Ref. [8], the continuity, momentum and energy equation for steady, incompressible and turbulent flow can be written in abbreviated form as:…”

Section: Mathematical Modelmentioning

confidence: 99%

Investigating two configurations of a heat exchanger in an Indirect Heating Integrated Collector Storage Solar Water Heater System (IHICSSWHS)

Mossad¹,

AL-Khaffajy²

2012

REPQJ

View full text Add to dashboard Cite

Due to the environmental impact of energy usage and increased price of fusel fuel, consumers need to be encouraged to use renewable energy sources. The IHISSWHS (indirect heating integrated collector storage solar water heater system) is one of the most economical systems. It incorporates the collection of a solar energy component and a hot water storage component in one unit. The objective of this study was to investigate ways to enhance the thermal performance of the system. Two configurations of the system were studied: system with double row HX (heat exchanger) and tube length of 16.2 m, and system with single row HX and tube length of 8.1 m and 10.8 m. The service water tube inside diameter was also varied to 10.7 mm and 17.1 mm. The steady state continuity, momentum and energy equations were numerically solved, using FLUENT software. A standard k-ω turbulent model and surface-to-surface radiation model were used. The result showed that the system of 10.8 m tube length and single row HX provided higher outlet temperature than the system of 16.2 m and double row HX. Therefore, a significant reduction in cost and power usage can be achieved by using a single row HX.

show abstract

“…The numerical results showed that the nonlinear k - ε model can produce a more accurate turbulence field and pressure and friction coefficients than the linear k - ε model. Raisee and Hejazi (2007) investigated the developing turbulent flow through the straight rectangular channel with a sudden contraction to further examine the effectiveness of the nonlinear k - ε model. The results of this study showed that the sudden contraction creates a relatively small recirculation bubble immediately downstream of the contraction.…”

Section: Introductionmentioning

confidence: 99%

Computation of flow and heat transfer through channels with periodic dimple/protrusion walls using low-Reynolds number turbulence models

Fazli

Raisee

2019

HFF

View full text Add to dashboard Cite

Purpose This paper aims to predict turbulent flow and heat transfer through different channels with periodic dimple/protrusion walls. More specifically, the performance of various low-Re k-ε turbulence models in prediction of local heat transfer coefficient is evaluated. Design/methodology/approach Three low-Re number k-ε turbulence models (the zonal k-ε, the linear k-ε and the nonlinear k-ε) are used. Computations are performed for three geometries, namely, a channel with a single dimpled wall, a channel with double dimpled walls and a channel with a single dimple/protrusion wall. The predictions are obtained using an in house finite volume code. Findings The numerical predictions indicate that the nonlinear k-ε model predicts a larger recirculation bubble inside the dimple with stronger impingement and upwash flow than the zonal and linear k-ε models. The heat transfer results show that the zonal k-ε model returns weak thermal predictions in all test cases in comparison to other turbulence models. Use of the linear k-ε model leads to improvement in heat transfer predictions inside the dimples and their back rim. However, the most accurate thermal predictions are obtained via the nonlinear k-ε model. As expected, the replacement of the algebraic length-scale correction term with the differential version improves the heat transfer predictions of both linear and nonlinear k-ε models. Originality/value The most reliable turbulence model of the current study (i.e. nonlinear k-ε model) may be used for design and optimization of various thermal systems using dimples for heat transfer enhancement (e.g. heat exchangers and internal cooling system of gas turbine blades).

show abstract

Application of linear and non-linear low-Re k–ε models in two-dimensional predictions of convective heat transfer in passages with sudden contractions

Cited by 10 publications

References 10 publications

Turbulent forced convection flow adjacent to inclined forward step in a duct

Turbulent forced convection flow adjacent to inclined forward step in a duct

Investigating two configurations of a heat exchanger in an Indirect Heating Integrated Collector Storage Solar Water Heater System (IHICSSWHS)

Computation of flow and heat transfer through channels with periodic dimple/protrusion walls using low-Reynolds number turbulence models

Contact Info

Product

Resources

About