Influence of helical tube dimensions on open channel natural convection heat transfer

Heo, Jeong-Hwan; Chung, Bum-Jin

doi:10.1016/j.ijheatmasstransfer.2012.02.043

Cited by 25 publications

(10 citation statements)

References 16 publications

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“…When compared with temperature measurement, this technique is attractive as it provides a simple, cheap, and accurate measurement method through measurement of the electric current [11,12]. This technique was developed by several researchers [13][14][15][16] and the methodology has been tested to various flow conditions such as forced, natural, and mixed convection [17][18][19][20][21][22][23] and now is well-established. Nusselt number would depend on all three numbers: Pr, Re and Ra.…”

Section: Experiments Methodologymentioning

confidence: 99%

The influence of tip clearance and Prandtl number on turbulent forced convection heat transfer of rectangular fins

Park

Chung

2016

Heat Mass Transfer

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Mass transfer coefficient [m/s] H Fin height [m] I lim Limiting current density [A/m 2 ] K Thermal conductivity [W/m K] L Length of base plate [m] N Number of electrons in charge transfer reaction Nu Dh Nusselt number (h h D h /k) p Pressure [N/m 2 ] Pr Prandtl number (ν/α) Q Total heat transfer rate [W] Ra L Rayleigh number (Gr L Pr) Re Dh Reynolds number (VD h /ν) S Fin spacing [m] Sc Schmidt number (ν/D m ) t Fin thickness [m] t n Transference number T Temperature [K] U x Uncertainty of x V Mean velocity [m/s] W Width of the base plate [m] y Distance to nearest wall [m] y + Dimensionless wall distance (ρμ τ y/μ) Greek symbols α Thermal diffusivity [m 2 /s] β Volume expansion coefficient [1/K] μ Viscosity [kg/m s] ν Kinematic viscosity [m 2 /s] ρ Density [kg/m 3 ]

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Section: Experiments Methodologymentioning

confidence: 99%

The influence of tip clearance and Prandtl number on turbulent forced convection heat transfer of rectangular fins

Park

Chung

2016

Heat Mass Transfer

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“…reported the use of mass transfer experiments. Chung et al [22][23][24][25][26][27][28] have also published a series of experimental results applying the methodology for various flow conditions and geometries. The physical properties were determined by using Equations 3 to 10, which were developed by Fenech and Tobias.…”

Section: Analogy Conceptmentioning

confidence: 99%

Natural convection of melted core at the bottom of nuclear reactor vessel in a severe accident

2017

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SummaryA hypothetical severe accident was investigated when nuclear fuels are melted.Experiments were performed for natural convection heat transfer of the melted core at the bottom of the reactor vessel. To achieve highly buoyant force, mass transfer experiment was adopted by using copper electroplating system based on the analogy concept. Mean and local Nusselt numbers were measured and compared for 2 different configurations of the melted core: 2-layer and 3-layer oxide pools. The phenomenological analysis was carried out comparing with 2 different oxide pool configurations of the present works and the existing studies. Heat ratio of the lower head to the top plate was affected by Prandtl number and geometrical difference. Compared with the existing studies, the Nu of lower head were about 40% lower, and those of the top plate were about 60% higher. The local Nusselt number ratio of the lower head gradually increased along the upper region and did not become affected by thermal conditions of the top plate. The local top plate Nusselt numbers for the 2D test rig were uniform, while those for the 3D test rig had steep slope with the highest Nusselt number at the center. 1 There are over 440 commercial nuclear power plants around the world. However, the release of radioactive materials would lead significant consequences to people and environments. The Fukushima Dai-ich nuclear power plant accident shed light on the severe accident phenomena in the nuclear industry. A nuclear power plant severe accident is the hypothetical situation accompanying the nuclear fuel melt by the various initial incidents together with

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“…The advantages of using helical coils as a heat exchanger/reactor over straight tubes are: (i) helical coils are more compact and hence have a higher area per unit volume, which gives rise to high-space time yield, (ii) the rate of heat transfer inside helical coils is much higher than in straight tubes 12 . Although the heat and mass transfer behavior of the outer and inner sides of helical coils was studied under different hydrodynamic conditions [12][13][14][15][16] , no previous studies have been reported on the use of inert fixed beds to enhance the rate of heat or mass transfer at the coil outer surface. The mass transfer behavior of the outer surface of a helical tube was studied using the electrochemical technique, which involves measuring the limiting current of the cathodic reduction of K 3 Fe(CN) 6 in a large excess of NaOH as a supporting electrolyte 17 .…”

Section: Introductionmentioning

confidence: 99%

Intensification of the Rate of Diffusion-controlled Electrochemical and Catalytic Reactions at a Helical Coil by a Fixed Bed Turbulence Promoter

El-Naggar¹

2018

Chem.Biochem.Eng.Q.

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Influence of helical tube dimensions on open channel natural convection heat transfer

Cited by 25 publications

References 16 publications

The influence of tip clearance and Prandtl number on turbulent forced convection heat transfer of rectangular fins

The influence of tip clearance and Prandtl number on turbulent forced convection heat transfer of rectangular fins

Natural convection of melted core at the bottom of nuclear reactor vessel in a severe accident

Intensification of the Rate of Diffusion-controlled Electrochemical and Catalytic Reactions at a Helical Coil by a Fixed Bed Turbulence Promoter

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