Related Papers
International Journal of Heat and Mass Transfer
A study of turbulent heat transfer in curved pipes by numerical simulation
2013 •
Michele Ciofalo
Heat Transfer in Turbulent Flow Through Tube with Rod-Pin Inserts
Jamal Uddin Ahamed
International Journal of Thermal Sciences
Laminar flow and heat transfer in U-bends: The effect of secondary flows in ducts with partial and full curvature
Periodica Polytechnica Transportation Engineering
Heat Transfer in a Circular Pipe with Artificially Perturbed Laminar and Turbulent Air Flow
1988 •
Trinh Van Quang
Artificially generated perturbation has been superposed on steady-state air flow before entering a pipe heated by about constant heat flux, to examine heat transfer under these circumstances. Periodic perturbation had a shape of half sine or square wave. Compared to unperturbed flow, unambiguous improvement of heat transfer throughout the tested range of Reynolds numbers was observed. The role of frequency and that of the waveform were manifested by the position and extension of the transient domain between laminar and turbulent flow, ,while there was no effect on the Nusselt number neither in laminar nor in turbulent domains, where, however, increase of the perturbation intensity entrained a uniform improvement of heat transfer at the same rate. Formulae haYe been presented for determining the critical Reynolds number and the Nusselt number.
Experimental study of the heat transfer for a tube bundle in a transversally flowing air
2006 •
George Darie
The simplest form of cross flow heat exchanger may be regarded as a series of identical heat transfer surfaces in a transverse stream that each has an influence on, and is in turn influenced by its neighbour. Therefore, in order to obtain a prediction for the heat transfer rate to or from a bundle of surfaces in cross flow it is usual to initially consider a single surface in isolation as a basis for correlation. In one of the most common arrangements, heat is transferred between a fluid flowing through a bundle of tubes and another fluid flowing transversely over the outside of the tubes. The main goal of this study is the experimental determination of the convective heat transfer coefficient transferred between a fluid, which is the air, flowing through a bundle of tubes in a transversally flowing air in a staggered arrangement and the comparing with the theoretical correlations.
Heat transfer coefficients for laminar to turbulent flow in tubes at constant heat flux.
Josua P Meyer
Due to constraints and changes in operating conditions, heat exchangers are often forced to operate under conditions of transitional flow. However, the heat transfer and flow behavior in this regime is relatively unknown. By describing the transitional characteristics it would be possible to design heat exchangers to operate under these conditions and improve the efficiency of the system. This study was aimed at obtaining experimental data for water flowing through a smooth tube with an inner diameter of 8 mm under constant heat flux conditions. Four heat flux test cases were considered namely: 1 409, 3 354, 5 009 and 6 881 W/m 2. The experiments covered a Reynolds number range of 500 to 8 800, a Prandtl number range of 4 to 7, a Nusselt number range of 6 to 67, and a Grashof number range of 750 to 25 600. Experiments have shown a smooth transition from laminar to turbulent flow.
Springer
Numerical investigation of turbulent flow and heat transfer in flat tube
2019 •
Dr. Davood Toghraie
In the present study, the fluid flow and heat transfer were numerically investigated in a flat tube under the constant heat flux using finite volume method and SIMPLEC algorithm. Also in this study, the range of Reynolds number is 5000–20,000, the range of dimensionless pitch (PN = PD/DL) is 1–2.33, and the range of dimensionless depth (DN = DD/DL) is 0.233–0.433. The use of second-order discretization for solving the governing equations on flow has made acceptable agreement between result between empirical and numerical results. The presence of dimples inside the channel, due to the creation of significant changes in flow physics and temperature field, considerably affects the flow and heat transfer parameters. The results indicate that by increasing Reynolds number, the convection heat transfer (Nusselt number) and the friction factor rise. Also, by decreasing the dimensionless pitch and increasing the dimensionless depth of dimple, Nusselt number and friction factor increase. The changes of Nusselt number are approximately related to the changes of dimensionless pitch and dimensionless depth of dimple, while the changes of friction factor are greatly related to the changes of dimensionless depth than the changes of dimensionless pitch. Based on the figures of average Nusselt number, using dimple in higher Reynolds numbers and constant DN ratio has a positive effect on Nusselt number increase. The main reason is the creation of stronger vortexes and better mixture of flow in higher Reynolds numbers. Hence, in average Nusselt number curves and in each constant DN ratio, the difference between graphs in Reynolds numbers of 2000 and 15,000 is higher than Reynolds numbers of 5000 and 10,000.
International Journal of Heat and Mass Transfer
Heat transfer in turbulent fluids—I. Pipe flow
1987 •
Victor Yakhot
Journal of Enhanced Heat Transfer
Heat Transfer in Turbulent Flow Through Tube with Wire-Coil Inserts
2005 •
Abdul Wazed
Experimental Heat Transfer
Heat Transfer and Pressure Drop Characteristics in Turbulent Flow through a Tube
2012 •
Masjuki Haji Hassan
An experimental investigation has been carried out for turbulent flow through a tube with perforated strip inserts. Strips were of mild steels with circular holes of different diameters. Flow varies, with ranging Reynolds numbers from 15,000 to 47,000. Air velocity, tube wall temperatures, and pressure drops were measured for a plain and strip-inserted tube. The heat transfer coefficient and friction factor were found to be 2.80 times and 1.8 times, respectively, that of the plain tube. The heat transfer performance was evaluated and found to be 2.3 times that of the plain tube based on constant blower power. © 2012 Taylor & Francis Group, LLC. http://www.tandfonline.com/doi/pdf/10.1080/08916152.2011.623819 http://www.tandfonline.com/doi/abs/10.1080/08916152.2011.623819#.Ux6IqM69gtE
