Simple method of predicting friction factors of turbulent flow in non-circular channels

Abstract

Abstract-On the basis of friction factor relationships of a simple model a method is developed which allows the prediction of friction factors for turbulent flow in non-circular channels if only the geometry factor of the pressure drop relationship for laminar flow is known. The proposed method of calculation is tested with numerous experimental results from the literature with respect to non-circular channels such as triangular shaped ducts, eccentric annuli and rod bundles in hexagonal and square arrays in circular tubes, hexagonal and square channels. It turns out that the proposed method provides an excellent description of all the experimental data at hand.channel wall and rods; annular zone parameter; wall distance; dimensionless wall distance y+ =

Performance assessment of longitudinal flow through rod bundle arrangements using entropy generation minimization approach

“…It is realized that the validity of the present analysis is hugely dependent on the correctness of the empirical correlations in predicting friction factor and heat transfer coefficients determined experimentally by Cheng and Todreas [5], Presser [8] and Weisman [9]. A common practice in subchannel pressure drop and heat transfer experiments is to compare the results with an equivalent annular zone solution as described in details in Todreas and Kazimi [47] and Rehme [1,2,48]. The equivalent annulus model as depicted in Todreas and Kazimi [47] has been shown in Fig.…”

“…It was concluded that the pressure drop coefficients for closely packed rod bundles deviate hugely from that for a circular pipe. Subsequently, Rehme [2] proposed a transcendental equation to predict the friction factor in various non-circular channels. Deissler and Taylor [3,4] analyzed fully developed turbulent flow and heat transfer in triangular and square arrays.…”

URANS simulation of the turbulent flow in tight lattice bundle

“…With the development of measurement techniques, more experiments were presented in the late 1990 [4][5][6][7][8][9], which indicate that the turbulent flow in a rod bundle has completely different characteristics compared to that in a pipe. A high mixing in the gap region was observed, which was once explained by the secondary flow.…”

A Numerical Analysis on Nanofluid Mixed Convection in Triangular Cross-Sectioned Ducts Heated by a Uniform Heat Flux

“…Furthermore, literature covers different fluids, like gas, liquid, non-Newtonian fluids, and, recently, nanofluids [14,20,21]. An experimental approach [4,17] or analytical [22] and numerical methods [21,23,24] have been adopted. Shah and London [25] performed a huge and exhaustive review about theoretical and experimental analyses on laminar forced convection and heat transfer in noncircular ducts.…”