An Experimental Study on Heat Transfer in a Pulsating Pipe Flow. 2nd Report, Phase-Averaged Turbulent Characteristics.

誠太, 一色; 輝夫, 小幡; 伸英, 笠木; 賢, 平田

doi:10.1299/kikaib.59.2522

Cited by 3 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimental studies on pulsating turbulent flow were conducted actively [1][2][3][4][5][6][7][8][9][10]. All of the measurements were made for fully developed flows with small oscillating velocity amplitudes.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of heat transfer in pulsating turbulent flow in a pipe

Wang¹,

Zhang²

2005

International Journal of Heat and Mass Transfer

105

View full text Add to dashboard Cite

Convection heat transfer in pulsating turbulent flow with large velocity oscillating amplitudes in a pipe at constant wall temperature is numerically studied. A low-Reynolds-number (LRN) k-e turbulent model is used in the turbulence modeling. The model analysis indicates that Womersley number is a very important parameter in the study of pulsating flow and heat transfer. Flow and heat transfer in a wide range of process parameters are investigated to reveal the velocity and temperature characteristics of the flow. The numerical calculation results show that in a pulsating turbulent flow there is an optimum Womersley number at which heat transfer is maximally enhanced. Both larger amplitude of velocity oscillation and flow reversal in the pulsating turbulent flow also greatly promote the heat transfer enhancement.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical analysis of heat transfer in pulsating turbulent flow in a pipe

Wang¹,

Zhang²

2005

International Journal of Heat and Mass Transfer

105

View full text Add to dashboard Cite

show abstract

“…It is of interest to compare instantaneous values varying during a period. One of the few experimental papers where such data are given is that by Isshiki et al [15]. Note that Isshiki et al [15] performed their experiments at low amplitudes of oscillation of flow rate, when the values of period average quantities do Owing to thermal inertia and convective heat transfer, hardly any oscillation of the Nusselt number is present in this mode.…”

Section: Unsteady-state Flow Of Liquid Of Constant Propertiesmentioning

confidence: 99%

“…Figure 4 gives the ratio of the period average value of the Nusselt number [15], (3,4) calculation for quasi-steady-state and high-frequency quasi-laminar flows. a maximum which is the more significant, the higher the oscillation amplitude A.…”

Section: Unsteady-state Flow Of Liquid Of Variable Propertiesmentioning

confidence: 99%

Hydrodynamics and Heat Transfer in Pulsating Turbulent Pipe Flow of a Liquid of Variable Properties

Valueva

2005

High Temp

View full text Add to dashboard Cite

The effect of the variability of properties on the characteristic features of heat transfer and of pulsating turbulent pipe flow of incompressible liquid is investigated. The results are obtained by using the method of finite differences to solve numerically a set of equations of motion, continuity, and energy written in a narrow channel approximation. The set is closed by relaxation equations for turbulent stress and turbulent heat flux. A stable difference scheme is used, which is valid for high relative amplitudes of oscillation. The calculations are performed for a dropping liquid in view of the temperature dependence of viscosity. The results of calculation of heat transfer and friction resistance for two limiting cases of steady-state flow of a liquid of variable properties and of pulsating weakly nonisothermal flow fit well the available experimental data.

show abstract

DNS of turbulent heat transfer in pulsating channel flow

Yamazaki

Oda

Matsumoto

et al. 2020

Transactions of the JSME (In Japanese)

View full text Add to dashboard Cite

A pulsating turbulent channel flow at constant wall temperature difference condition is studied by direct numerical simulation (DNS) to clarify the effect of pulsation frequency on turbulence statistics and heat transfer. The flow pulsation was forced to a turbulent channel flow by sinusoidal variation of pressure gradient. Four pulsation frequencies were tested for Womersley number, Wo = 19.8, 28.0, 39.6 and 56.0 at steady-state friction Reynolds number, Re s = 300. Phase-averaged friction velocity and Nusselt number change periodically, showing different amplitude and phase lag to bulk Reynolds number, depending on Womersley number. Consequently, it is found that the time-local dissimilarity between momentum and heat transfer occurs due to the flow pulsation. Also, the phase-averaged streamwise velocity and turbulent kinetic energy can be scaled with phase-averaged friction velocity at low Womersley number. On the other hand, at high Womersley number, the phase-averaged turbulent kinetic energy is scaled with the time-averaged friction velocity. This fact implies that near-wall turbulent eddy structure changes following bulk Reynolds number variation at low frequency, but it cannot follow the rapid variation at high frequency and ends up holding near steady-state structure. This view is supported by the behavior of vortex structures which virtually does not change during one cycle at high Womersley number.

show abstract

An Experimental Study on Heat Transfer in a Pulsating Pipe Flow. 2nd Report, Phase-Averaged Turbulent Characteristics.

Cited by 3 publications

References 0 publications

Numerical analysis of heat transfer in pulsating turbulent flow in a pipe

Numerical analysis of heat transfer in pulsating turbulent flow in a pipe

Hydrodynamics and Heat Transfer in Pulsating Turbulent Pipe Flow of a Liquid of Variable Properties

DNS of turbulent heat transfer in pulsating channel flow

Contact Info

Product

Resources

About