Results 241 to 250 of about 532,316 (313)

Turbulent Heat Transfer

1982
Heat transfer problems in turbulent flows are mainly described by empirical relationships Nu = Nu(Re, Pr). The progress of modeling the turbulent heat transfer is quite poor. For the turbulent momentum transfer on the other hand we have a lot of semiempirical modeling assumptions which lead to good results for engineering purposes.
M. Jischa, H. B. Rieke
openaire   +1 more source

Heat transfer augmentation of internal flow using twisted tape insert in turbulent flow

Heat Transfer Engineering, 2020
Heat transfer augmentation of turbulent single-phase flow in a concentric tube heat exchanger with short-length twisted tape inserts was numerically examined herein. The twisted tape length ratios were 0.25, 0.5, 0.75, and 1.0.
A. Wijayanta, Mirmanto, Muhammad Aziz
semanticscholar   +1 more source

Heat Transfer in Isotropic Turbulence

Journal of Applied Physics, 1952
The postulated problem of heat transfer in a stationary isotropic turbulence under constant small temperature gradient is examined from both Lagrangian and Eulerian points of view. By combination of Taylor's ``diffusion by continuous movements'' and a new temperature fluctuation equation somewhat like the wellknown turbulent energy equation, it is ...
openaire   +1 more source

The buoyancy force and flow acceleration effects of supercritical CO2 on the turbulent heat transfer characteristics in heated vertical helically coiled tube

International Journal of Heat and Mass Transfer, 2018
Numerical simulations are performed to investigate the turbulent heat transfer characteristics of supercritical CO2 in heated vertical helically coiled tube, and primary focus is to analyze the mechanism of buoyancy force and flow acceleration on the ...
Shijie Zhang, Xiaoxiao Xu, Chao Liu, Yadong Zhang, C. Dang   +4 more
semanticscholar   +1 more source

MICROSCALES OF TURBULENCE-HEAT TRANSFER CORRELATIONS

Proceeding of International Heat Transfer Conference 10, 1994
Firstly, the paper develops a thermal mesomicroscale to shed light on the turbulent forced convection for fluids and viscous oils. Secondly, the paper gives a review of the recent results on the buoyancy driven turbulent flows and introduces the microscales appropriate for these flows.
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Heat transfer in convective turbulence

Nonlinearity, 1996
Summary: We investigate the bulk scaling of the convective heat transport in the Boussinesq equations. An a priori bound on the scaling exponent is obtained without making any assumptions on the turbulent fluctuations. If horizontal gradients of temperature fluctuations are relatively small near the boundary then different scaling regimes are obtained.
Constantin, Peter, Doering, Charles R.
openaire   +1 more source

Heat transfer and turbulent simulation of nanomaterial due to compound turbulator including irreversibility analysis

International Journal of Heat and Mass Transfer, 2019
In this research, combined turbulator was proposed to achieve good thermal performance. Steady turbulent flow of copper oxide nanofluid with homogeneous model was simulated involving k-ɛ model. Among various geometric parameters, height of turbulator (b)
M. Sheikholeslami, M. Jafaryar, M. Hedayat, A. Shafee, Zhixiong Li, T. Nguyen, Mohsen Bakouri   +6 more
semanticscholar   +1 more source

THE MOMENTUM AND VORTICITY TRANSFER THEORIES OF TURBULENT HEAT TRANSFER

Canadian Journal of Physics, 1954
The case of heat transfer by a cylindrical turbulent region is examined further theoretically from the standpoint of the vorticity transfer analogy. The radial distribution of the eddy diffusivity for vorticity is considered and, on the logarithmic velocity distribution law for fully developed turbulence, this quantity is found to be negative ...
openaire   +1 more source

HEAT TRANSFER IN ISOTROPIC TURBULENCE

Chemical Engineering Communications, 1981
The direct interaction approximation (Kraichnan 1959) was used to calculate thermal eddy diffusivities, intensities or temperature fluctuations, and various correlation functions for heat transfer in an isotropic turbulent flow with a uniform mean temperature gradient.
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Turbulent Heat Transfer in Corotating Annular Disks

Numerical Heat Transfer, Part B: Fundamentals, 1985
This paper deals with heat transfer in turbulent flow through corotating annular disks. The dual-stream flow influx enters from both sides and proceeds radially outward. The governing equations are solved by a finite-difference technique using a modified SIMPLER algorithm. The effects of the disk size and spacing, influx Reynolds number, and rotational
Yoon S. Sim, Wen-Jei Yang
openaire   +1 more source