The Flow and Pressure Losses in Smooth Pipe Bends of Constant Cross Section

Smith, A. G. R.

doi:10.1017/s0368393100078846

Cited by 15 publications

(1 citation statement)

References 5 publications

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“…The influence of tangent pipes (straight sections of pipe upstream and downstream of the bend) on the pressure loss through pipe bends was studied by Ward, 11 who compared the value of resistance coefficient as the downstream pressure measurement location was varied. There have been various publications focused on the swirl intensity and the swirl switching phenomena in the downstream tangent of a pipe bend, e.g., those by Sudo et al ., 12 Sakaibara and Sonope, 13 Hellstrom et al ., 14 and Kim et al .…”

Section: Introductionmentioning

confidence: 99%

Numerical approach for prediction of turbulent flow resistance coefficient of 90° pipe bends

Ayala

Cimbala

2020

Proceedings of the Institution of Mechanical Engineers, Part E:

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In the present study turbulent flow in a circular cross-sectioned 90° smooth-walled pipe bend has been investigated numerically. The geometry of the model consisted of three sections: a straight inlet pipe of length 52 diameters, a 90° bend with radius of curvature 1 diameter, and a straight downstream pipe of length 52 diameters. Reynolds numbers from 5,000 to 120,000 were considered. The numerical model was developed using COMSOL Multiphysics and all turbulent flow simulations were performed using the standard k- ε turbulence model. The main objective of this work was to estimate the resistance coefficient of pipe bends using not only pressure drop but also information of the flow behavior far downstream in the outlet pipe. Wall static pressure and velocity fields of the secondary flow were illustrated to provide information of the flow behavior in the bend and downstream of the pipe bend. Furthermore, swirl intensity of secondary flow was presented in order to describe its behavior as the flow develops in the outlet pipe. Estimations of resistance coefficient were calculated and compared to other studies. It was found that the procedure used in this study is a viable method for a more accurate estimation of resistance coefficient values for turbulent pipe flows containing 90° bends. For best accuracy in either experimental or computational analyses, it is recommended that pressure in the downstream tangent be measured at no less than fifty diameters downstream of the bend to avoid influence of the secondary flow.

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Section: Introductionmentioning

confidence: 99%

Numerical approach for prediction of turbulent flow resistance coefficient of 90° pipe bends

Ayala

Cimbala

2020

Proceedings of the Institution of Mechanical Engineers, Part E:

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Teaching turbulent flow through pipe fittings using computational fluid dynamics approach

Gajbhiye

Kulkarni

Tiwari

et al. 2020

Engineering Reports

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The largest network of fluid transportation in the world is through pipelines.During the transportation of fluids through pipes, several "fittings" are used in the piping system such as elbows, T-junctions, reducers, expanders, bends, couplings, valves, etc. The flow complexities in pipe fittings are accounted for the pressure drop in piping network design. The pressure drop is estimated using the loss coefficient or equivalent length method using standard charts. Computational fluid dynamics (CFD) is a reliable tool to estimate pressure drop and understand nonidealities in pipe fittings. The use of CFD in the advanced level course in transport phenomena/fluid flow for piping network design can help students to implement modern mathematical tools as well as evaluate standard protocols followed in the industries. In this article, an interactive teaching methodology has been implemented to investigate the hydrodynamics in various pipe fittings (elbow, bend, Tee, and reducer) by actually visualizing the flow. The three-dimensional flow visualization is used to demonstrate the nonidealities such as separation, swirling, dead zones, etc. The CFD simulations of pipe fittings provided a new learning experience to the students that would help them to predict the pressure drops in industrial piping network systems. The outcome from the students' survey showed that the proposed CFD methodology assisted them to gain a better understanding of conventional Chemical Engineering subjects of "Transport Phenomena" and "Fluid Dynamics" in an innovative way. K E Y W O R D Scomputational fluid dynamics, head loss coefficient, pipe fittings, turbulence models 1

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A numerical study of laminar and turbulent flows in a two‐dimensional bend with or without a guide vane

Kotb

Mokhtarzadeh‐Dehghan

Ward-Smith

1988

Numerical Meth Engineering

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SUMMARYA numerical study of the flow in a two-dimensional 90" circular-arc bend is presented. The study is based on the solution of the governing equations using a finite volume technique. Both laminar and turbulent flows are considered. Particular attention is given to the occurrence and size of the separation regions and, in this respect, the effects of Reynolds number and bend radius to height ratio are discussed. The study includes the effect of a guide vane, placed in the bend, on the flow characteristics. It is shown that the emerging velocity distribution is more uniform than that associated with flow in a bend without a guide vane. The presence of a guide vane is shown to suppress the formation of regions of flow separation. Comparisons are made between the effects on the flow of two different designs of guide vane.

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The Flow and Pressure Losses in Smooth Pipe Bends of Constant Cross Section

Cited by 15 publications

References 5 publications

Numerical approach for prediction of turbulent flow resistance coefficient of 90° pipe bends

Numerical approach for prediction of turbulent flow resistance coefficient of 90° pipe bends

Teaching turbulent flow through pipe fittings using computational fluid dynamics approach

A numerical study of laminar and turbulent flows in a two‐dimensional bend with or without a guide vane

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