Numerical study of supercritical-pressure fluid flows and heat transfer of methane in ribbed cooling tubes

Xu, Keke; Tang, Lijun; Meng, Hua

doi:10.1016/j.ijheatmasstransfer.2015.01.041

Cited by 72 publications

(12 citation statements)

References 32 publications

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“…Experimental and numerical investigations have been extensively conducted on heat transfer performance of fluids at supercritical pressures, but the previous studies in the open literature are mainly focused on supercritical heat transfer of CO 2 and H 2 O [4][5][6][7][8]. Compared to CO 2 and H 2 O, the database on the convective heat transfer of hydrocarbon fuels is at a relative small scale [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer Characteristics of Al2O3-Kerosene and Fe3O4-Kerosene Nanofluids Flowing in a Minitube at Supercritical Pressures

Huang¹,

Wu²,

Li³

2018

Int J Astronaut Aeronautical Eng

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Regenerative cooling system is thought to be an effective and practical solution to better thermal management for high heat flux applications. In this paper, the potential of nanofluids as regenerative coolants at supercritical pressures was evaluated. Two-step method was applied to prepare Al 2 O 3-kerosene and Fe 3 O 4-kerosene nanofluids. Then experiments were carried out to study the heat transfer characteristics of nanofluids flowing in a vertical minitube at supercritical pressures. Parametric effects of mass flow rate, heat flux, pressure and particle content on the heat transfer performance are presented. Results show that increasing the flow rate or the working pressure could enhance the heat transfer performances, yet higher heat flux leads to poorer heat transfer performances. Besides, the addition of nanoparticles tend to deteriorate heat transfer at supercritical pressures because deposition of the nanoparticles smoothens the wall roughness and presents an additional thermal resistance. As the particle content increases, the heat transfer performance becomes worse.

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Section: Introductionmentioning

confidence: 99%

Heat Transfer Characteristics of Al2O3-Kerosene and Fe3O4-Kerosene Nanofluids Flowing in a Minitube at Supercritical Pressures

Huang¹,

Wu²,

Li³

2018

Int J Astronaut Aeronautical Eng

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“…Regarding the above issue, there are many research viewpoints to the special heat transfer of supercritical fluids, e.g. operating conditions (Pizzarelli et al , 2015; Sunden et al , 2016) such as heat flux (a crucial factor to the abnormal heat transfer), turbulence models (Pandey et al , 2017; Gustavo et al , 2018), predictive correlations (Zahlan et al , 2017; Shokri and Ebrahimi, 2019), the effect of buoyancy force and thermal acceleration (Jackson, 2017; Yu et al , 2013), flow instability (Wang et al , 2013a; Yan et al , 2018) and enhanced heat transfer (Li et al , 2016; Xu et al , 2015), also including a transient study of HTD (Dutta and Giridhar, 2017). In our opinion, the effect of the wall conduction is a matter of concern due to the sensibility to the heat flux (Buzzi et al , 2019; Ehsan et al , 2018).…”

Section: Introductionmentioning

confidence: 99%

Effect of wall conduction on the heat transfer characteristics of supercritical n-decane in a horizontal rectangular pipe for cooling of a scramjet combustor

Xie

Sundén

2020

HFF

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Purpose The purpose of this paper is to numerically study the influence of wall conduction on the heat transfer of supercritical n-decane in the active regenerative cooling channels. Design/methodology/approach A horizontally placed rectangular pipe with a solid zone and another one without a solid zone were used. A drastic variation of thermo-physical properties was emphatically addressed. After the verification of mesh and turbulence models comparing with the experimental results, a mesh number of 4.5 M and the low Reynolds number SST k-ω turbulence model were chosen. The solution of the governing equations and the acquisition of the numerical results were executed by the commercial software FLUENT 2020 R1. Findings The numerical results indicate that there is a heat transfer deterioration (HTD) potential for the upper wall, lower wall and sidewall with the decrease of mass flux. Due to wall conduction, the distribution of the fluid temperature at spanwise-normal planes becomes uniform and this feature also takes advantage of the relatively uniform transverse velocity. For the streamwise-normal planes, the low fluid temperature appears close to the upper wall at the region near the sidewall and vice versa for the region near the centre. Undoubtedly, the secondary flow at the cross-section plays a crucial role in this process and the relatively cool mainstream is affected by the vortices. Originality/value This study warns that the wall conduction must be considered in the practical design and thermal optimization due to the sensibility of thermo-physical properties to the heat flux. The secondary flow caused by the buoyancy force (gravity) plays a significant role in the supercritical heat transfer and mixed convection heat transfer should be further studied.

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“…In order to further enhance the heat transfer and suppress the heat transfer deterioration of supercritical fluids, various heat transfer enhancement techniques were widely investigated experimentally and numerically, such as internally ribbed tubes (Xu et al, 2015;Li et al, 2015a, b;Zhao et al, 2014;Wang et al, 2009Wang et al, , 2012Ackerman, 1970), helical coiled tubes and curved tubes, (Li et al, 2010), etc. However, most of the studies were devoted to the heat transfer of supercritical water and carbon dioxide in enhanced tubes.…”

Section: Introductionmentioning

confidence: 99%

Comparison of heat transfer characteristics of aviation kerosene flowing in smooth and enhanced mini tubes at supercritical pressures

Sundén

Huang

2016

International Journal of Numerical Methods for Heat &Amp; Fluid Flow

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Purpose – The purpose of this paper is to numerically investigate the heat transfer performance of aviation kerosene flowing in smooth and enhanced tubes with asymmetric fins at supercritical pressures and to reveal the effects of several key parameters, such as mass flow rate, heat flux, pressure and inlet temperature on the heat transfer. Design/methodology/approach – A CFD approach is taken and the strong variations of the thermo-physical properties as the critical point is passed are taken into account. The RNG k-ε model is applied for simulating turbulent flow conditions. Findings – The numerical results reveal that the heat transfer coefficient increases with increasing mass flow rate and inlet temperature. The effect of heat flux on heat transfer is more complicated, while the effect of pressure on heat transfer is insignificant. The considered asymmetric fins have a small effect on the fluid temperature, but the wall temperature is reduced significantly by the asymmetric fins compared to that of the corresponding smooth tube. As a result, the asymmetric finned tube leads to a significant heat transfer enhancement (an increase in the heat transfer coefficient about 23-41 percent). The enhancement might be caused by the re-development of velocity and temperature boundary layers in the enhanced tubes. With the asymmetric fins, the pressure loss in the enhanced tubes is slightly larger than that in the smooth tube. A thermal performance factor is applied for combined evaluation of heat transfer enhancement and pressure loss. Research limitations/implications – The asymmetric fins also caused an increased pressure loss. A thermal performance factor ? was used for combined evaluation of heat transfer enhancement and pressure loss. Results show that the two enhanced tubes perform better than the smooth tube. The enhanced tube 2 gave better overall heat transfer performance than the enhanced tube 1. It is suggested that the geometric parameters of the asymmetric fins should be optimized to further improve the thermal performance and also various structures need to be investigated. Practical implications – The asymmetric fins increased the pressure loss. The evaluation of heat transfer enhancement and pressure loss Results showed that the two enhanced tubes perform better than the smooth tube. It is suggested that the geometric parameters of the asymmetric fins should be optimized to further improve the thermal performance and also various structures need to be investigated to make the results more engineering useful. Originality/value – The paper presents unique solutions for thermal performance of a fluid at near critical state in smooth and enhanced tubes. The findings are of relevance for design and thermal optimization particularly in aerospace applications.

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Numerical study of supercritical-pressure fluid flows and heat transfer of methane in ribbed cooling tubes

Cited by 72 publications

References 32 publications

Heat Transfer Characteristics of Al2O3-Kerosene and Fe3O4-Kerosene Nanofluids Flowing in a Minitube at Supercritical Pressures

Heat Transfer Characteristics of Al2O3-Kerosene and Fe3O4-Kerosene Nanofluids Flowing in a Minitube at Supercritical Pressures

Effect of wall conduction on the heat transfer characteristics of supercritical n-decane in a horizontal rectangular pipe for cooling of a scramjet combustor

Comparison of heat transfer characteristics of aviation kerosene flowing in smooth and enhanced mini tubes at supercritical pressures

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