scholarly journals New explicit correlation to compute the friction factor under turbulent flow in pipes

2021 ◽  
Vol 25 (7) ◽  
pp. 439-445
Author(s):  
Alan Olivares Gallardo ◽  
Rodrigo Guerra Rojas ◽  
Marco Alfaro Guerra
Keyword(s):  
Turbulent Flow ◽  
Friction Factor ◽  
Hydraulic Systems ◽  
Head Losses ◽  
Explicit Correlation

HIGHLIGHTS The correlation facilitates the calculation of head losses in hydraulic systems. The correlation was design for regimes of high and low turbulence. The best performance of the correlation is obtained for a range of roughness that goes from 10-2 to 5 × 10-3.

scholarly journals Major and minor head losses in a hydraulic flow circuit: experimental measurements and a Moody’s diagram application

2020 ◽  
Vol 45 (3) ◽  
pp. 47-56
Author(s):  
Aline Amaral Madeira
Keyword(s):  
Friction Factor ◽  
Correlation Coefficients ◽  
Head Loss ◽  
Rapid Expansion ◽  
Experimental Measurements ◽  
Hydraulic Systems ◽  
Local Loss ◽  
Hydraulic Flow ◽  
Head Losses ◽  
Flow Circuit

Domestic and industrial hydraulic drainage networks have gradually become more complicated because of the cities’ rapid expansion. In surcharged hydraulic systems, the head losses may become rather significant, and should not be neglected because could result in several problems. This work presents an investigation about major and minor head losses in a hydraulic flow circuit, simulating the water transport in a drainage network at room temperature (298.15 K) under atmospheric pressure (101,325 Pa). The losses produced by the fluid viscous effect through the one used cast-iron rectilinear pipe (RP-11) and the localized losses generated by two flow appurtenances, one fully open ball valve (BV-1) and one module of forty-four 90º elbows (90E-8) were experimentally measured. Experimental data generated head-loss curves and their well fitted to potential regressions, displaying correlation coefficients (R2) of 0.9792, 0.9924, and 0.9820 for BV-1, 90E-8, and RP-11, respectively. Head loss experimental equations and local loss coefficients through BV-1 and 90E-8 were determined successfully. The Moody’s diagram application proved to be a quite appropriate tool for an approximate estimation of Darcy-Weisbach friction factor. A good approximation between friction factor values obtained via experimental measurements and the Moody’s diagram was observed with mean absolute deviate of 0.0136.

Numerical and Experimental Analysis of Turbulent Flow in Corrugated Pipes

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Henrique Stel ◽  
Rigoberto E. M. Morales ◽  
Admilson T. Franco ◽  
Silvio L. M. Junqueira ◽  
Raul H. Erthal ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Velocity Magnitude ◽  
Geometric Configurations ◽  
Corrugated Surfaces ◽  
Friction Factors

This article describes a numerical and experimental investigation of turbulent flow in pipes with periodic “d-type” corrugations. Four geometric configurations of d-type corrugated surfaces with different groove heights and lengths are evaluated, and calculations for Reynolds numbers ranging from 5000 to 100,000 are performed. The numerical analysis is carried out using computational fluid dynamics, and two turbulence models are considered: the two-equation, low-Reynolds-number Chen–Kim k-ε turbulence model, for which several flow properties such as friction factor, Reynolds stress, and turbulence kinetic energy are computed, and the algebraic LVEL model, used only to compute the friction factors and a velocity magnitude profile for comparison. An experimental loop is designed to perform pressure-drop measurements of turbulent water flow in corrugated pipes for the different geometric configurations. Pressure-drop values are correlated with the friction factor to validate the numerical results. These show that, in general, the magnitudes of all the flow quantities analyzed increase near the corrugated wall and that this increase tends to be more significant for higher Reynolds numbers as well as for larger grooves. According to previous studies, these results may be related to enhanced momentum transfer between the groove and core flow as the Reynolds number and groove length increase. Numerical friction factors for both the Chen–Kim k-ε and LVEL turbulence models show good agreement with the experimental measurements.

FORCED CONVECTION BASED HEAT TRANSFER ANALYSIS OF SPHERICAL DIMPLE AND PROTRUSION SURFACE IN TURBULENT FLOW

2017 ◽  
Vol 41 (5) ◽  
pp. 771-786 ◽  
Author(s):  
Ashif Perwez ◽  
Shreyak Shende ◽  
Rakesh Kumar
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Vortex Flow ◽  
Rectangular Channel ◽  
Heat Transfer Analysis ◽  
Flow Structures ◽  
Transfer Enhancement ◽  
Heat Transfer Augmentation ◽  
Thermal Boundary Conditions

An experimental and numerical investigation is performed to study the effect of dimple and protrusion geometry on the heat transfer enhancement and the friction factor of surfaces with dimples and protrusions subjected to turbulent flow. The parameters used to compare the spherical dimples and protrusions are Nusselt Number, friction factor, and flow pattern. These parameters are obtained for a Reynolds number of 10500-60900. The spherical dimple results showed the greater heat transfer, which is about 6.97% higher and pressure loss which is 5.07% lower than the spherical protrusion. The realistic heat transfer augmentation capabilities of channels with dimples and protrusions can be studied from the experimental results. The comparison is made with respect to the smooth rectangular channel under the same flow and thermal boundary conditions. The numerical analysis is performed which shows the different vortex flow structures of the spherical dimples and protrusions channel.

Friction factor and heat transfer of nanofluid in the turbulent flow through a 90° bend

2021 ◽  
Vol 33 (6) ◽  
pp. 1105-1118
Author(s):  
Pei-jie Zhang ◽  
Jian-zhong Lin ◽  
Xiao-ke Ku
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Flow Through

Computation of Normal Depth in Trapezoidal Open Channel Using the Rough Model Method

2014 ◽  
Vol 955-959 ◽  
pp. 3231-3237
Author(s):  
Bachir Achour
Keyword(s):  
Aspect Ratio ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Linear Dimension ◽  
Open Channel ◽  
Discharge Energy ◽  
Flow Discharge ◽  
Model Method ◽  
Rough Model ◽  
Depth Relationship

The recurring problem of calculating the normal depth in a trapezoidal open channel is easily solved by the rough model method. The Darcy-Weisbach relationship is applied to a referential rough model whose friction factor is arbitrarily chosen. This leads to establish the non-dimensional normal depth relationship in the rough model. Through a non-dimensional correction factor of linear dimension, the aspect ratio and therefore normal depth in the studied channel is deduced. Keywords: Rough model method, Trapezoidal channel, Normal depth, Turbulent flow, Discharge, Energy slope.

Application of an Analytical Model for Simulating Hydraulic Systems Containing Internal Lines With Turbulent Flow

2017 ◽  
Author(s):  
David A. Hullender ◽  
Natalie N. Snyder ◽  
Jan C. Gans
Keyword(s):  
Turbulent Flow ◽  
Frequency Response ◽  
Analytical Model ◽  
Simulation Models ◽  
Hydraulic Systems ◽  
Mean Flow ◽  
Pressure Transients ◽  
Fluid Properties ◽  
The Mean ◽  
Hydraulic Fracking

It is not uncommon for simulation models for the dynamics of hydraulic systems to contain fluid lines with turbulent flow. This paper demonstrates applications of an analytical model for pressure transients in lines with turbulent flow for lines with boundary conditions defined by hydraulic components such as pumps, valves, actuators, and restrictions; the model can be simplified for cases of laminar flow. The equations for conducting simulations with time varying inputs and for calculating eigenvalues of systems in which fluid lines are internal components are formulated. For an example demonstrating application of the equations, the model is used to simulate and optimize the performance of a hydraulic fracking system which involves the pumping of large volumes of water with additives through pipes under turbulent flow conditions into rock fissures. Specifically, the model is used to generate the frequency response of the flow transients in the pipe resulting from pump flow pulsations. This frequency response is then used to compute the eigenvalues of the system. The model is then used to conduct time domain simulations to determine the potential flow amplifications into rock fissures associated with pulsing the flow from the pump at the resonant frequency of the pressure transients in the pipe. The results reveal flow amplifications into the fissures of up to 22 times depending on the pulse shape of the input flow, the Reynolds number of the mean flow, the fluid properties of the slurry, and the length and diameter of the pipe.

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