A Review of Mass (Heat) Transfer Measurements Using Naphthalene Sublimation

Goldstein, R. J.; CHO, H.H.

doi:10.1016/b978-0-444-81619-1.50006-x

Cited by 3 publications

(3 citation statements)

References 80 publications

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“…The computational model was validated against data published in the work of Saboya and Sparrow [16] as their paper is widely acknowledged as the standard for validation of the studies of heat transfer from finned surfaces. They used the naphthalene sublimation technique [25] to obtain local mass transfer coefficients (Sherwood numbers Sh) on the fin surface of the one-row plate-fin tube heat exchanger. The Sherwood number distribution can be converted to heat transfer coefficients by utilization of the heat-mass transfer analogy:…”

Section: Validation Of the Numerical Modelmentioning

confidence: 99%

“…Prandtl number and thermal conductivity are assumed as for pure air (Pr = 0.7, λ = 0.026 W/m/K)the concentration of naphthalene is too low to significantly influence the thermophysical properties of the fluid. Saboya and Sparrow [16] assumed Sc = 2.5, yet it is an outdated value, and for room temperature the Sc = 2.28 is now recommended [25]. Local Sherwood numbers [16] were converted to heat transfer coefficients according to (14) and prepared to validate the CFD simulation.…”

Section: Validation Of the Numerical Modelmentioning

confidence: 99%

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Study of the Influence of the Lack of Contact in Plate and Fin and Tube Heat Exchanger on Heat Transfer Efficiency under Periodic Flow Conditions

et al. 2021

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Plate fin-tube heat exchangers are widely used in air conditioning and refrigeration systems and other industry fields. Various errors made in the manufacturing process can result in the formation of an air gap between the tube and fin. Several numerical simulations were carried out for a symmetric section of plate fin-tube heat exchanger to study the influence of air gap on heat transfer under periodic flow conditions. Different locations and sizes of an air gap spanning 1/2 circumference of the tube were considered for the range of airflow velocities. Velocity and temperature fields for cases with air gap were compared with ideal thermal contact cases. Blocking of heat flow by the gap leads to the reduction of heat transfer rate. Fin discontinuity in the front of the tube causes the smallest reduction of the heat transfer rate in comparison to the ideal tube-fin contact, especially for thin slits. The rear gap position is the worst in the smallest gap range. Therefore, reversing the flow direction can lead to up to a 15% heat transfer increase, if mainly the rear gaps are present. The introduction of a thin slit in the front of the tube leads to convective heat transfer enhancement, which should be further investigated.

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Section: Validation Of the Numerical Modelmentioning

confidence: 99%

Section: Validation Of the Numerical Modelmentioning

confidence: 99%

Study of the Influence of the Lack of Contact in Plate and Fin and Tube Heat Exchanger on Heat Transfer Efficiency under Periodic Flow Conditions

et al. 2021

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“…Dnaph is determined from a correlation recommended by Goldstein and Cho (1993). During the experiment, extraneous sublimation losses by natural convection are corrected from the total sublimation rate based on a natural convection rate and the measurement duration.…”

Section: Data Acquisition System and Measurementsmentioning

confidence: 99%

Total-Coverage Discrete Hole Wall Cooling

Cho

Goldstein

1995

Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration

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The present study investigates heat/mass transfer for flow through perforated plates for application to combustor wall and turbine blade film cooling. The experiments are conducted for hole length-to-diameter ratios of 0.68 to 1.5, for hole pitch-to-diameter ratios of 1.5 and 3.0, for gap distance between two parallel perforated plates of 0 to 3 hole diameters, and for Reynolds numbers of 60 to 13,700. Local heat/mass transfer coefficients near and inside the cooling holes are obtained using a naphthalene sublimation technique. Detailed knowledge of the local transfer coefficients is essential to analyze thermal stress in turbine components. The results indicate that the heat/mass transfer coefficients inside the hole surface vary significantly due to flow separation and reattachment. The transfer coefficient near the reattachment point is about four and half times that for a fully developed circular tube flow. The heat/mass transfer coefficient on the leeward surface has the same order as that on the windward surface because of a strong recirculation flow between neighboring jets from the array of holes. For flow through two in-line layers, the transfer coefficient affected by the gap spacing is approximately 100% higher on the windward surface of the second wall and is about 20% lower on the inside hole surface than that with a single layer. The transfer coefficient on the leeward surface is not affected by upstream flow conditions due to probably strong recirculation in the wake flow.

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Local and Average Characteristics of Heat/Mass Transfer Over Flat Tube Bank Fin With Four Vortex Generators per Tube

Wang¹,

Kong²,

Gao³

et al. 2002

Journal of Heat Transfer

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The analogy between heat and mass transfer has been used to obtain local and average heat transfer characteristics over a complete flat tube-fin element with four vortex generators (VGs) per tube. Several types of surfaces involved in heat transfer process such as fin surface mounted with VGs, its back surface (mounted without VGs) and flat tube surface are considered. The mass transfer experiments are performed using naphthalene sublimation method. The effects of the fin spacing and VG parameters such as height and attack angle on heat transfer and pressure drop are investigated. The comparisons of heat transfer enhancement with flat tube-fin element without VG enhancement under three constraints are carried out. The local Nusselt number distribution reveals that VGs can efficiently enhance the heat transfer in the region near flat tube on fin surface mounted with VGs. On its back surface the enhancement is almost the same as on the fin surface mounted with VGs but enhanced region is away from flat tube wall with some distance. Average results reveal that increasing of VG height and attack angle increases the enhancement of heat transfer and pressure drop, whereas small fin spacing causes greater increase of pressure drop. The heat transfer performance, correlations of Nusselt number and friction factor are also given.

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A Review of Mass (Heat) Transfer Measurements Using Naphthalene Sublimation

Cited by 3 publications

References 80 publications

Study of the Influence of the Lack of Contact in Plate and Fin and Tube Heat Exchanger on Heat Transfer Efficiency under Periodic Flow Conditions

Study of the Influence of the Lack of Contact in Plate and Fin and Tube Heat Exchanger on Heat Transfer Efficiency under Periodic Flow Conditions

Total-Coverage Discrete Hole Wall Cooling

Local and Average Characteristics of Heat/Mass Transfer Over Flat Tube Bank Fin With Four Vortex Generators per Tube

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