Linear correlation of heat transfer and friction in helically-finned tubes using five simple groups of parameters

Zdaniuk, Gregory J.; Luck, Rogelio; Chamra, Louay M.

doi:10.1016/j.ijheatmasstransfer.2007.10.022

Cited by 20 publications

(9 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of the tube under analysis, the transition occurs for Reynolds numbers from the range of 17,000-21,000. The authors of works concerning the testing of tubes with micro-ribs report similar observations [3,[5][6][7]38]. Figure 10 presents a comparison of the data obtained from the measurements, the developed correlation, the formulae available from the literature, and the equation specific to smooth tubes.…”

Section: The Curve Of Equationsupporting

confidence: 52%

“…and Haaland [30]: 1 f = −1.8log 10 6.9Re + ε 3.7d 1.11 (7) Thermal and flow conditions change, depending on the tube's geometrical dimensions, the rib helical angles, and the number of ribs in the cross-section. The most essential geometrical dimensions of rifled tubes are presented in Figure 1.…”

Section: Friction Factor In Smooth and Rifled Tubesmentioning

confidence: 99%

“…The same measuring results are used to select the coefficients in Equation (12). The difference is related to the proposal for a correlation based on five simple groups of parameters [7]. Neural networks and measuring data from a few other publications were used in Reference [6], enabling selection of the coefficients in Equation (13).…”

Section: Friction Factor In Smooth and Rifled Tubesmentioning

confidence: 99%

“…The results were also used to develop the friction factor and the heat transfer coefficient formulae. The formulae were found using a group of five parameters [6], also using neural networks to calculate the required quantities and constants [7].…”

mentioning

confidence: 99%

See 3 more Smart Citations

Experimental Determination of the Friction Factor in a Tube with Internal Helical Ribs

Grądziel

Majewski²

2019

Energies

View full text Add to dashboard Cite

Due to the extended geometry of internally rifled tubes with helical ribs, the rate of convective heat transfer within them is much higher compared to smooth tubes. Simultaneously, a rise in the contact surface area between the fluid and the solid body increases the friction factor. This paper presents the results of experimental testing performed to determine the friction factor in an internally rifled tube with helical ribs. The tests were carried out on a purpose-built test stand. The tested object was a rifled tube used in the evaporator of a once-through supercritical power boiler operating in a power plant in Poland. The friction factor results obtained from testing are compared to the results of calculations performed by means of correlations known from the literature. Finally, using experimental data, a new correlation is developed that enables the determination of the friction factor in internally rifled tubes with helical ribs.

show abstract

Section: The Curve Of Equationsupporting

confidence: 52%

Section: Friction Factor In Smooth and Rifled Tubesmentioning

confidence: 99%

Section: Friction Factor In Smooth and Rifled Tubesmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Experimental Determination of the Friction Factor in a Tube with Internal Helical Ribs

Grądziel

Majewski²

2019

Energies

View full text Add to dashboard Cite

show abstract

“…The following relations that make it possible to determine the dimensionless Chilton-Colburn j factor are presented in [6,7,20]…”

Section: (2)mentioning

confidence: 99%

Experimental determination of the heat transfer coefficient in internally rifled tubes

Grądziel

Majewski²,

Majdak

2019

THERM SCI

View full text Add to dashboard Cite

Original scientific paper https://doi.org/10.2298/TSCI19S4163G Development of the heat transfer surfaces on the tube inside makes it very difficult or even impossible to determine the heat transfer coefficient analytically. This paper presents the experimental determination of the coefficient in an internally rifled tube with spiral ribs. The tests are carried out on a laboratory stand constructed at the Institute of Thermal Power Engineering of the Cracow University of Technology. The tube under analysis has found application in a supercritical circulating fluidized bed boiler. The heat transfer coefficient local values are determined for the Reynolds numbers included in the range of ~6000 to ~50000 and for three ranges of the heating elements power. As the medium flows through internally rifled tubes with spiral ribs, the heat transfer process gets intensified compared to similar processes taking place in smooth tubes. Based on the obtained experimental data, a correlation is developed enabling determination of the dimensionless Chilton-Colburn j factor. The equation form is selected so that a comparison with existing results of tests performed on rifled tubes can be made. Comparing the Nusselt number values calculated based on the developed correlation with those obtained using other correlations described in the literature, it can be observed that the criterial number is about twice higher. The research results confirm the thesis that the element internal geometry has a substantial impact on the heat transfer process.

show abstract

Effect of porous slab thickness and Darcy number on thermohydraulic transport characteristics of Ag–TiO₂/water hybrid nanofluid flow‐through partially porous wavy channels

Kumar

Pandey

2022

Heat Trans

View full text Add to dashboard Cite

The present article investigates the effect of varying porous slab thicknesses (S = 0-0.4) and Darcy number (Da = 10 −6 -10 −2 ) on the thermohydraulic performance of three different corrugated channels (triangular, sinusoidal, and trapezoidal) embedded with partially filled porous media.Ag-TiO 2 /water hybrid nanofluid (ϕ = 0-0.04) is taken as coolant flowing at Re = 400. Results revealed that the thermal performance (average Nusselt number, Nu avg and enhancement ratio, ER) augments with the increase in porous slab thickness and decrease in Darcy number.However, the hydraulic performance reduces (i.e., an increase in pressure drop). To check the viability of the cooling system performance factor (PF) is evaluated which demonstrates variation in thermal performance considering pressure drop penalty also. It is demonstrated that among all configurations, the trapezoidal channel with porous slab thickness (S = 0.4) and Darcy number (Da = 10 −4 ) gives maximum enhancement thermal performance (110%) considering water as a coolant (ϕ = 0). Furthermore, enhancement in thermal performance by 210% is noticed as volume concentration ϕ of hybrid nanofluid varies from 0% to 4%. It is also evident that the value of PF for all corrugated channels is lower than 1 indicating

show abstract

Linear correlation of heat transfer and friction in helically-finned tubes using five simple groups of parameters

Cited by 20 publications

References 7 publications

Experimental Determination of the Friction Factor in a Tube with Internal Helical Ribs

Experimental Determination of the Friction Factor in a Tube with Internal Helical Ribs

Experimental determination of the heat transfer coefficient in internally rifled tubes

Effect of porous slab thickness and Darcy number on thermohydraulic transport characteristics of Ag–TiO₂/water hybrid nanofluid flow‐through partially porous wavy channels

Contact Info

Product

Resources

About

Linear correlation of heat transfer and friction in helically-finned tubes using five simple groups of parameters

Cited by 20 publications

References 7 publications

Experimental Determination of the Friction Factor in a Tube with Internal Helical Ribs

Experimental Determination of the Friction Factor in a Tube with Internal Helical Ribs

Experimental determination of the heat transfer coefficient in internally rifled tubes

Effect of porous slab thickness and Darcy number on thermohydraulic transport characteristics of Ag–TiO2/water hybrid nanofluid flow‐through partially porous wavy channels

Contact Info

Product

Resources

About

Effect of porous slab thickness and Darcy number on thermohydraulic transport characteristics of Ag–TiO₂/water hybrid nanofluid flow‐through partially porous wavy channels