Numerical investigation on heat transfer performance and flow characteristics in enhanced tube with dimples and protrusions

Xie, Shuai; Zhang, Liang; Wang, Yulin; Ding, Hu; Zhang, Jie

doi:10.1016/j.ijheatmasstransfer.2018.01.106

Cited by 76 publications

(21 citation statements)

References 23 publications

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“…On the other hand, the friction factor of the circular dimpled channel is doubled for some cases done by Rao et al [5]. The heat transfer enhancement of circular dimple is reported to be about 1.25 times that of the flat channel as Reynolds number increases while the friction factor remains at about 1.55 in the results obtained by Xie et al [6]. It highlights the fact that the drag and heat transfer performance of circular dimpled surfaces is highly sensitive to the dimpled geometry and flow conditions [7].…”

Section: Introductionmentioning

confidence: 84%

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

Khoo¹,

Chen²,

Tay³

et al. 2021

Proceedings of the 6th World Congress on Momentum, Heat and Mass Transfer

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In this study, the flow characteristics and enhanced heat transfer performance of circular dimples in a channel flow were numerically analysed and compared with a flat channel. The effect of shifting the deepest point of the dimples in turbulent flow on their drag and heat transfer performance are also discussed. The strength and extent of the induced recirculating flow is suppressed significantly when the deepest point is shifted downstream, enhancing the heat transfer performance of the dimpled wall. At the same time, the flow structure above the dimpled wall is manipulated by the geometry changes. The flow impingement on the dimpled wall increases drag; consequently, the power required to drive the flow is increased. A parametric study is conducted to optimize the shifting of the deepest point to maximize heat transfer performance while minimizing the drag increase.

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Section: Introductionmentioning

confidence: 84%

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

Khoo¹,

Chen²,

Tay³

et al. 2021

Proceedings of the 6th World Congress on Momentum, Heat and Mass Transfer

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“…(1) e gas is an ideal gas (2) e gas flow is quasi-steady heat flow (3) e fluid in the pipeline is a single-phase gas (4) e diameter of the pipeline is unchanged during pigging e unsteady flow dynamics can be modeled based on the fundamental fluid dynamic equations [11,17,18,23]: continuity equation, momentum equation, and energy equation, respectively, as follows:…”

Section: Model Of Gas Flow In a Hillymentioning

confidence: 99%

Modeling and Simulation of Pigging for a Gas Pipeline Using a Bypass Pig

Zhang

Zhou

2020

Mathematical Problems in Engineering

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The pipeline inspection gauge (PIG, lowercase pig is commonly used) with a bypass valve is widely used in pipeline inspection because it operates at a low speed without reducing the flow rate. Understanding the dynamics of a bypass pig in a gas pipeline would contribute to the design of the pig and the control of pig speed. This paper deals with the dynamic model for the process of a bypass pig travelling through a hilly gas pipeline. The method of characteristics (MOC) is used to solve the equations of unsteady gas flow. The backward flow of the gas in the bypass valve and pipe is shown by a simulation of pigging for a hilly gas pipeline. Parametric sensitivity analysis of pigging in the horizontal gas pipe using a bypass pig is then carried out. The results indicate that the speed of a bypass pig is most sensitive to the gas speed in the pipe followed by the bypass area and the friction of the pig. A formula, obtained from the results of the simulations using response surface methodology (RSM), is presented to predict the steady speed of a bypass pig in the horizontal gas pipeline.

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“…The unsteady flow dynamics can be modeled based on the continuity equation, momentum equation, and energy equation respectively as follows (Esmaeilzadeh et al, 2009Nguyen et al, 2001aXie et al, 2018):…”

Section: Gas Flow Model In Hilly Pipelinementioning

confidence: 99%

Simulation of Pigging with a Brake Unit in Hilly Gas Pipeline

Zheng

2019

JAFM

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Pigging is a routine operation in the oil and gas industry. In this paper, the governing equation of pig speed was combined with the gas flow equations. The transient equations of gas flow are solved by the method of characteristics (MOC). An experiment was carried out to test the proposed pigging model. The measured speed of the pig coincides with the calculated speed well. The process of a pig carrying a brake unit to pass over a hilly gas pipeline is simulated. The results indicate that the brake unit would lead to a sharp increase of the pressure on the tail of the pig, because the pig is dragged by the brake unit and thus prevented to accelerate together with the gas column in a downhill gas pipeline. This way, the pig speed in a downhill gas pipeline is much lower by using a brake unit, but the speed of pig still can hardly be controlled in the desired range. Furthermore, response surface methodology (RSM) is used to study the maximum speed of pig with/without a brake unit in downhill gas pipeline. Based on the results of the RSM simulations, two equations are present to predict the maximum speed of a pig in a downhill gas pipeline.

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Numerical investigation on heat transfer performance and flow characteristics in enhanced tube with dimples and protrusions

Cited by 76 publications

References 23 publications

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

Modeling and Simulation of Pigging for a Gas Pipeline Using a Bypass Pig

Simulation of Pigging with a Brake Unit in Hilly Gas Pipeline

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