Fluid Flow In Pipe Research Articles

Temperature Changes of Cryogenic Fluid Flow in Pipe Bends due to Viscous Heating Effect

Temperature Changes of Cryogenic Fluid Flow in Pipe Bends due to Viscous Heating Effect

Temperature Changes of Cryogenic Fluid Flow in Pipe Bends due to Viscous Heating Effect

Temperature Changes of Cryogenic Fluid Flow in Pipe Bends due to Viscous Heating Effect

Computational Analysis of Rheological Secondary Flow in a Pipe-Manifold Containing In-Plane Double Bends

Non-Newtonian fluid flow in pipe bends is inevitable in industrial applications. Previous researchers have extensively explored Newtonian flow through curved ducts. However, the non-Newtonian counterpart gets little attention. We study the turbulent flow of shear-dependent fluids obeying the Power-Law model in a pipe manifold containing an in-plane double bend. Ostwald–de Waele's power law is used to model the fluid's rheology. We utilize computational fluid dynamics (CFD) to solve Reynolds-averaged Navier–Stokes (RANS) equations with the k-ε turbulence model. We validate our numerical results with previous experimental results. The in-plane double bend perturbs the flow in the pipe manifold to develop a Prandtl's secondary flow of the first kind. A fully developed flow at the bend upstream is disturbed due to the bend's curvature and regains its fully developed characteristics upon a certain downstream length after the exit of the bend. We study the rheological characteristics of the secondary flow within the bend and the evolution of fluid flow at the bend downstream. We demonstrate that the centrifugal force-dominated secondary flow increases with a decrease of the non-Newtonian power-law index. We capture the camel's-back-shaped velocity profiles within the bend due to accelerating-decelerating flow. The study reveals that the average flow velocity increases along the bend with a corresponding pressure head loss. We quantify this velocity rise by a newly introduced non-dimensional number, viz. enhancement ratio. The double bend's enhancement ratio decreases with an increase in n.

Comparative study of the accuracy of friction factor correlations developed for flow of inelastic yield power-law fluids in pipes

An extensive review of the friction factor correlations used for pressure loss prediction of yield power-law (YPL) fluid flow in pipes has been conducted, and the results are summarized in this paper.A comparative study was also conducted to determine the predictive performances of various laminar and turbulent friction factor models developed for YPL fluid flow in pipes. Model predictions of frictional pressure losses were validated by comparing them with the experimentally measured pressure drop data obtained from the flow of several YPL fluids in pipes.Investigations were further extended to determine the impact of the variation of YPL fluid rheological characteristics (resulting from using different rheological characterization methods) on the pressure drop predictions.A wide range of generalized Reynolds numbers (i.e., 20 to 9000, as defined by the API-RP:13D) in a pipe flow configuration was considered in the analyses. The yield stress of the test fluids (determined by using the nonlinear curve fitting technique recommended by the API RP:13D) varied from 0.10 to 0.95 Pa.The results indicated that Hanks and Ricks' model predicted the pressure drop of YPL fluid flow in pipes better than any other models, both in laminar and turbulent flow regimes, matching the experimental data within a ±10% error range.Variations of the YPL model parameters (resulting from using different rheological characterization methods) significantly impacted the pressure drop predictions. Using YPL model parameters obtained from the non-iterative dual power law (DPL) approximation method (as recommended by API-RP:13D) and Hanks and Ricks' model yielded the most accurate pressure drop predictions for the pipe flow of YPL fluids.

A comparative study on thermohydraulic performance of multi-channel spoilers and staggered spoilers

Energy crisis has set back the global progress on economic development, because the non-renewable energy sources are unsustainable, and renewable energy sources are not yet reliable. Therefore, improving the efficiency of energy usage becomes increasingly significant. Heat is the largest energy end-use in the world, taking good advantage of it is one of the most important subjects. Tubular heat exchangers are widely used in both civil and industrial processes, and the consumption of energy can be greatly reduced by improving the efficiency of heat transfer in pipes. Adding inserts into the pipes is a main way to enhance heat transfer. This paper mainly studies two new types of spiral spoilers, namely multi-channel spoilers and staggered spoilers, using numerical methods. The former divides the pipe into several channels, and the latter has deflecting angles at the end of every spiral period. Experiments were also conducted to verify the numerical results. Aiming at analyzing thermohydraulic characteristics of fluid flow in pipes inserted with two types of spoilers separately, the effects of channel number (N), deflecting angle (φ), pitch ratio (p’/D) were studied under different Reynolds numbers (Re). Evaluation parameters including Nusselt number (Nu), friction factor (f), heat deficit loss (eT), mechanical deficit loss (ep), exergy loss (E*) and performance evaluation criteria (PEC) were all considered as indices. Results show that flow channels and deflecting angles generate better mixed fluid, which is conducive to heat transfer enhancement at the expense of more irreversible loss. Multi-channel spoilers with a channel number N = 2 and pitch ratio p’/D = 1.5 maintain the best balance between energy loss and heat transfer. The heat transfer enhancement reaches the best performance in staggered spoilers with a deflecting angle φ = 15°, 45.07% irreversible loss can be reduced compared with φ = 120°. Staggered spoilers can enhance heat transfer better, compared with multi-channel spoilers, especially in laminar flow.

Engineering method for calculating fluid flow in pipes with different cross sections in energy and technological processes

The flow of liquid through pipes with various configurations is found in many energy and technological processes. Knowledge of the distribution of velocity and flow through these pipes allows hydrological engineers to find resistance through the pipes and optimize the fluid pumping process. The article suggests a simple engineering method for finding the velocity over pipe sections

Shark Skin—An Inspiration for the Development of a Novel and Simple Biomimetic Turbulent Drag Reduction Topology

In this study, a novel but simple biomimetic turbulent drag reduction topology is proposed, inspired by the special structure of shark skin. Two effective, shark skin-inspired, ribletted surfaces were designed, their topologies were optimized, and their excellent drag reduction performances were verified by large eddy simulation. The designed riblets showed higher turbulent drag reduction behavior, e.g., 21.45% at Re = 40,459, compared with other experimental and simulated reports. The effects of the riblets on the behavior of the fluid flow in pipes are discussed, as well as the mechanisms of fluid drag in turbulent flow and riblet drag reduction. Riblets of various dimensions were analyzed and the nature of fluid flow over the effective shark skin surface is illustrated. By setting up the effective ribletted surface on structure’s surface, the shark skin-inspired, biomimetic, ribletted surface effectively reduced friction resistance without external energy support. This method is therefore regarded as the most promising drag reduction technique.

Non conservative products in fluid dynamics

Fluid flow in pipes with discontinuous cross section or with kinks is described through balance laws with a non conservative product in the source. At jump discontinuities in the pipes’ geometry, the physics of the problem suggests how to single out a solution. On this basis, we present a definition of solution for a general BV geometry and prove an existence result, consistent with a limiting procedure from piecewise constant geometries. In the case of a smoothly curved pipe we thus justify the appearance of the curvature in the source term of the linear momentum equation.These results are obtained as consequences of a general existence result devoted to abstract balance laws with non conservative source terms in the non resonant case.

Computational Fluid Dynamics Simulation and Analysis of Fluid Flow in Pipe: Effect of Fluid Viscosity

Computational Fluid Dynamics Simulation and Analysis of Fluid Flow in Pipe: Effect of Fluid Viscosity

On monotonic stability of elliptic pipe flow

It was previously shown that the linear stability of fluid flows in pipes significantly depends on their cross-sectional aspect ratio. The linear stability analysis allows for judging the asymptotic behavior of the basic flow disturbances; however, it says nothing about their possible transient growth, which can cause the so-called subcritical laminar–turbulent transition. The lower limit of the Reynolds numbers at which the growth of the kinetic energy of disturbances is possible is the energy critical Reynolds number. In the present work, for the Poiseuille flow in a pipe of axially uniform elliptic cross-section the dependence of the energy critical Reynolds number on the pipe aspect ratio A is computed for 1≤A≤5, based on the energy stability method. The dependence is non-monotonic under scaling providing the same flow rates at the same Reynolds numbers. In particular, at A≈2.3 the critical Reynolds number reaches its maximum, but then monotonically decreases with increasing A, becoming less than in a circular pipe, and tends to the energy critical Reynolds number of the plane Poiseuille flow under an appropriate scaling as A→∞. A qualitative explanation of the obtained dependence is proposed based on the analysis of the critical disturbances corresponding to the critical Reynolds number and their kinetic energy balance. The obtained dependence suggests that the change in the pipe aspect ratio may be a promising tool for the passive control of the laminar–turbulent transition in pipe flows and can be used together with other known approaches employed for this purpose.

A Survey on Distributed Fibre Optic Sensor Data Modelling Techniques and Machine Learning Algorithms for Multiphase Fluid Flow Estimation.

Real-time monitoring of multiphase fluid flows with distributed fibre optic sensing has the potential to play a major role in industrial flow measurement applications. One such application is the optimization of hydrocarbon production to maximize short-term income, and prolong the operational lifetime of production wells and the reservoir. While the measurement technology itself is well understood and developed, a key remaining challenge is the establishment of robust data analysis tools that are capable of providing real-time conversion of enormous data quantities into actionable process indicators. This paper provides a comprehensive technical review of the data analysis techniques for distributed fibre optic technologies, with a particular focus on characterizing fluid flow in pipes. The review encompasses classical methods, such as the speed of sound estimation and Joule-Thomson coefficient, as well as their data-driven machine learning counterparts, such as Convolutional Neural Network (CNN), Support Vector Machine (SVM), and Ensemble Kalman Filter (EnKF) algorithms. The study aims to help end-users establish reliable, robust, and accurate solutions that can be deployed in a timely and effective way, and pave the wave for future developments in the field.

Optimal Estimation of the Roughness Coefficient and Friction Factor of a Pipeline

Abstract This work addresses the estimation of two interrelated parameters of the fluid flow in pipes. First, a numerical and experimental evaluation of some proposed methods to compute the friction factor in turbulent regime is presented. Special attention is given to an explicit solution obtained through the Lambert W-function. Subsequently, a method to estimate the roughness coefficient using nonlinear optimization techniques is proposed, which then allows determining the friction factor from it. Numerical tests were performed for a wide range of operating points of a pipeline. In order to validate the proposed approach, experimental analysis was carried out on a pipeline pilot-plant. The results show the applicability and effectiveness of the proposed method.

Viscosity correction in convective heat transfer correlation of non-Newtonian fluid pipe flow: Revisited

The role of variable viscosity on the heat transfer in non-Newtonian fluid flow has not been adequately explored in the past. Typically, non-Newtonian fluids are described by the power-law type behaviour as τ=Kγ̇n (τ: shear stress; K: consistency index;γ̇: shear rate; n: power-law exponent). The viscosity correction factor in the form ofKwK∞m(w: wall; ∞: bulk) is a function of n. Traditionally, the Sieder-Tate correction for Newtonian fluid, μwμ∞-0.14 was the popular choice (μw: fluid viscosity at the wall, μ∞: bulk) (Metzner et al. 1957). This is the first work on postulating the viscosity correction from the fundamental boundary layer analysis in non-Newtonian fluid. The mathematical predictions are validated with the literature experimental data. Inaccurate estimation of the viscosity correction leads to under- or over-predictions of the heat transfer coefficient, consequently, affects the effective heat transfer area. The correlations developed in this work would help in improved area calculations, thus, better performance and economic benefits.

ANALISIS HASIL PERCOBAAN ALAT PRAKTIKUM RUGI-RUGI ALIRAN DALAM PIPA

The phenomenon of flow in a pipe is one of the experiments carried out in the Mechanical Phenomenon Practicum in bachellor of Mechanical Engineering. In this paper, we will describe the experimental results of the tool that was made in mechanical engineering prgram, west sumatera muhammadiyah university for the first time. The pump used is large enough to 1.0 HP, it is expected that the pressure will be high enough and cause turbulent flow. Measuring instruments installed are Pressure Gauge, Stopwatch, and Water Meter. Water is pumped from the source (reservoir) in the form of a tub to a network of pipes with diameters of ¾ ", ½" and 5/8 "by installing pressure sensors at the pump output and each of pipe. The water meter is useful for measuring the rate of water, resulting in greater flow losses. At the greater the flow velocity, resulting in a large Reynolds Number, while the velocity, at this time, namely by measuring the output capacity of 5 ml which is then measured the time needed using a stopwatch. The variation of the water flow rate is made by distinguishing the valve openings, namely 4/4 total openings then ¾, ½ and ¼. The experimental results show that the smaller the valve opening than the smaller the flow rateflow friction loss has not so effect because of the flow is in turbulent conditions. The design of this experimental tool is in compliance with the friction theory of fluid flow in pipes, closed flow, for the next stage it is necessary to develop a tool by entering the length per diameter factor (parameter)of the circulation pipe, further for laminar flow where the sensitivity of the Reynolds number has more effect on friction losses so need the precision measurement tools.

FSI Computation and Experimental Verification of Fluid Flow in Flexible Tubes

Abstract Presented paper is focused on the experimental and computational study of fluid flow in pipes with flexible walls. One possible real example of this phenomenon is the blood flow in arteries or their substitutes in the human body. The artery material itself should be understood as anisotropic and heterogeneous. Therefore, the experiment was carried out on the deforming tube, made of silicone (polydimethylsiloxane - PDMS). Obtained results and observed events were verified by numerical FSI simulations. Due to the large deformations occurring during loading of the tube, it was necessary to work with a dynamic mesh in the CFD part. Based on experimental testing of the tube material, a non-Hookean and Mooney-Rivlin material model were considered. Blood flowing in vessels is a heterogeneous liquid and exhibits non-Newtonian properties. In the real experimental stand has been somewhat simplified. Water, chosen as the liquid, belongs to the Newtonian liquids. The results show mainly comparisons of unsteady velocity profiles between the experiment and the numerical model.

Heavy Oil Laminar Flow in Corrugated Ducts: A Numerical Study Using the Galerkin-Based Integral Method

Fluid flow in pipes plays an important role in different areas of academia and industry. Due to the importance of this kind of flow, several studies have involved circular cylindrical pipes. This paper aims to study fully developed internal laminar flow through a corrugated cylindrical duct, using the Galerkin-based integral method. As an application, we present a study using heavy oil with a relative density of 0.9648 (14.6 °API) and temperature-dependent viscosities ranging from 1715 to 13000 cP. Results for different fluid dynamics parameters, such as the Fanning friction factor, Reynolds number, shear stress, and pressure gradient, are presented and analyzed based on the corrugation number established for each section and aspect ratio of the pipe.

Estimation of Equivalent Sand–Grain Roughness for Coated Water Supply Pipes

AbstractThe Colebrook equation gives the Darcy-Weisbach friction factor for fluid flow in pipes as a function of sand-grain roughness and the Reynolds number. Values of equivalent sand-grain roughn...

CFD simulation of two-phase gas/non-Newtonian shear-thinning fluid flow in pipes

The multiphase flow has always been a major concern since it is encountered in many industrial processes that are crucial. Gas/non-Newtonian two-phase flow is found in the upstream of the petroleum industry, where slug flow is the most common flow pattern. This flow pattern has complex hydrodynamics which is crucial to study and evaluate. This study assessed the two-phase gas/non-Newtonian fluid flow in different configurations of pipes. The model was developed using computational fluid dynamics with an orthogonal mesh to evaluate the behavior of the slug dynamics in the different configurations. The model volume of fluid was used to estimate and predict the most important parameters: pressure drop, slug frequency, and length. First, the model was validated with experimental data found in literature in a horizontal 9-m long glass pipe, with an inner diameter of 22.8 mm. The validation was made with carboxymethyl cellulose CMC–water solutions as test fluids. Two concentrations (w/w) of CMC were used: 1% and 6%. The overall average relative error of the model, taking into account the three parameters, was 24.9%. With this result, it was proceeded to evaluate the model and the effect in the slug flow in three different pipe trajectories: toe-down well, one undulation with a hump well and one undulation with a sump well. The comparison was made between results of a gas/Newtonian fluid flow and the gas/non-Newtonian fluid flow. It was found that the slug frequency and length vary in great form. The slug frequency increased in almost all the cases, and the slug length decreased.

Axial conduction and dissipation in oscillatory laminar pipe flow at low and high frequencies

The problem of fully developed laminar fluid flow in pipes, driven by an oscillatory pressure gradient, can be solved exactly for the time-dependent velocity field and related quantities such as flow rate and tidal displacement. When dissipation is neglected and the momentary axial variation of temperature is assumed to be linear, the corresponding thermal energy equation describing heat transfer along a pipe connecting two reservoirs at different temperatures can also be solved to yield exact solutions for the time-dependent temperature field, axial heat flux, and effective axial conductivity. In this paper, it is shown that these exact solutions for the unsteady temperature field are invalid at low Womersley numbers because the momentary axial variation of temperature is not linear. When the thermal energy equation is written in quasisteady form, approximate quasisteady analytical solutions can be found for the temperature field, which yield effective axial conductivities several orders of magnitude greater than those given by the low-Womersley-number, unsteady-flow solution. It is also shown that the conditions under which effects of dissipation on axial heat transfer become significant, at high Womersley numbers, can be determined by a simple criterion. When dissipation is significant, exact solutions for the unsteady temperature field are invalid at high Womersley numbers because the momentary axial variation of temperature is also nonlinear.

Evaluation of Electrical Resistance Tomography imaging algorithms to monitor settling slurry pipe flow

Electrical Resistance Tomography (ERT) is used in process tomography to measure multi-phase fluid flow in pipes. ERT has the advantage of a non-invasive interface, but has challenges such as noise, a relatively low spatial resolution and the ill-posedness of the inverse problem. Many different image reconstruction algorithms have been developed in the medical imaging community, which offer promise to help improve ERT performance. However, no evaluation or methodology for comparison of different algorithms for industrial applications is available. To provide such an evaluation, we tested six ERT reconstruction algorithms for the identification in static and dynamic flow situations. Metrics were developed to evaluate the algorithms in terms of image quality and accuracy, different objects/shapes and coarse solids bed levels were tested statically in a spool piece, and bed levels dynamically in a pipe loop. An algorithm comparison methodology was developed and used to evaluate the different images based on the results obtained. Overall, results show significant variability between reconstruction algorithms, with some giving poor results at the pipe boundary and others poor results at the centre of the image. We identified two high performing algorithms and show that averages of individual algorithm images can achieve improved performance.