Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
3.4
1.8
Journals
Fluids
Special Issues
Modelling Flows in Pipes and Channels
share announcement

Modelling Flows in Pipes and Channels

A special issue of Fluids (ISSN 2311-5521).

Deadline for manuscript submissions: 31 December 2024 | Viewed by 6127

Special Issue Editor

Dr. Kamil Urbanowicz

E-Mail Website
Guest Editor
Department of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology Szczecin, Piastów 19, 70-310 Szczecin, Poland
Interests: water hammer; unsteady pipe flow; transient flow, cavitation; unsteady friction; retarded strain; numerical modelling; analytical solutions
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Welcome to the Special Issue on "Modelling Flows in Pipes and Channels". This issue serves as a comprehensive exploration of fluid flow dynamics within conduits, encompassing both steady-state and transient phenomena.

Fluid flows in pipes and channels are ubiquitous in hydraulic engineering, influencing various industrial, environmental, and infrastructure applications. Understanding the intricacies of these flows is paramount for optimizing system design, enhancing operational efficiency, and ensuring safety.

In this special issue, we aim to bridge the gap between steady-state and transient analyses, recognizing their symbiotic relationship in elucidating the complexities of fluid dynamics. Steady flow regimes provide foundational insights into the equilibrium states of fluid systems, offering invaluable benchmarks for comparison with transient events. Meanwhile, transient problems, characterized by sudden changes in flow rate, pressure, or other parameters, present unique challenges that demand sophisticated modelling techniques and precise numerical simulations.

We invite contributions that delve into mathematical formulations, boundary conditions, geometric influences, fluid properties, numerical techniques, and validation strategies pertinent to both steady and transient flow modelling. By embracing a holistic approach, we seek to advance our understanding of fluid flow dynamics in pipes and channels, facilitating the development of robust models and predictive tools.

Researchers and practitioners are encouraged to submit their work, encompassing theoretical advancements, experimental investigations, and practical applications. By fostering collaboration and knowledge exchange, this special issue aims to drive innovation in hydraulic engineering, ultimately leading to safer, more efficient, and sustainable fluid transport systems.

We're looking forward to your contributions and to the collective insights that will come from this interdisciplinary endeavor.

Dr. Kamil Urbanowicz
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Fluids is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • transient flow
  • unsteady flow
  • numerical modelling
  • experimental research
  • frequency-dependent friction
  • cavitation
  • fluid-structure interaction FSI
  • leak detection
  • plastic pipes and channels
  • hydraulic losses

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (7 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

27 pages, 14405 KiB  
Article
Features of Motion and Heat Transfer of Swirling Flows in Channels of Complex Geometry
by Sergey Dmitriev, Alexey Sobornov and Andrey Kurkin
Fluids 2024, 9(12), 293; https://doi.org/10.3390/fluids9120293 - 10 Dec 2024
Viewed by 330
Abstract
The computational and experimental study results of swirling single-phase coolant motion and heat transfer for the standard operation parameters of a nuclear power plant are presented. The experimental model is a vertical heat exchanger of a “pipe in a pipe” type with the [...] Read more.
The computational and experimental study results of swirling single-phase coolant motion and heat transfer for the standard operation parameters of a nuclear power plant are presented. The experimental model is a vertical heat exchanger of a “pipe in a pipe” type with the countercurrent movement of coolants. Six different swirlers (three with a constant twist pitch and three with a variable pitch) were considered. The heat exchanger temperature field was measured at various combinations of coolant flow rates, and a channel pressure drop for each swirl was determined. Computational studies were performed using the Omega-based Reynolds stress model and SST model with a correction for curvature streamlines. A good agreement between numerical and experimental data was obtained. Based on the velocity and temperature fields, swirling flow motion features in channels with a variable swirl pitch were discovered. For each intensifier, the effectiveness criterion in comparison with a pipe channel was determined. Full article
(This article belongs to the Special Issue Modelling Flows in Pipes and Channels)
►▼ Show Figures

Figure 1

20 pages, 7640 KiB  
Article
Mesh Sensitivity Analysis of Axisymmetric Models for Smooth–Turbulent Transient Flows
by Pedro Leite Ferreira and Dídia Isabel Cameira Covas
Fluids 2024, 9(11), 268; https://doi.org/10.3390/fluids9110268 - 19 Nov 2024
Viewed by 405
Abstract
The current paper focuses on the assessment of radial mesh influence on the description of the transient event obtained by an axisymmetric model. The objective is to reduce computational effort while accurately calculating hydraulic transients in smooth–turbulent pressurized pipes. The analyzed pipe system [...] Read more.
The current paper focuses on the assessment of radial mesh influence on the description of the transient event obtained by an axisymmetric model. The objective is to reduce computational effort while accurately calculating hydraulic transients in smooth–turbulent pressurized pipes. The analyzed pipe system has a reservoir–pipe–valve configuration with an inner diameter of 0.02 m and a total length of 14.96 m, with the initial discharge being equal to 120 × 10−3 L/s (Re = 7638). An extensive study is carried out with 80 geometric sequence meshes by varying the total number of cylinders, the geometric common ratio, and the pipe axial discretization. The benefit of increasing the geometric common ratio is highlighted. A detailed comparison between two meshes is presented, in which the best mesh (i.e., the one with the lowest computational effort) has a three-fold higher value of the geometric common ratio. The two meshes show small differences for the instantaneous valve closure, limited to a time interval immediately after the arrival of the pressure surge and only during the first pressure wave. The dynamic characterization of the transient phenomenon demonstrates the in-depth consistency between the model results and the hydraulic transients’ phenomenon in terms of the piezometric head, the wall shear stress, and the mean velocity time-history, in comparison to the results obtained with the shear stress, lateral velocity, and axial velocity profiles. Full article
(This article belongs to the Special Issue Modelling Flows in Pipes and Channels)
►▼ Show Figures

Figure 1

18 pages, 3360 KiB  
Article
On the Modelling of Asymptotic Wavefronts in Long Ducts with Chambers
by Alan E. Vardy
Fluids 2024, 9(10), 240; https://doi.org/10.3390/fluids9100240 - 14 Oct 2024
Viewed by 629
Abstract
A novel method of determining the possible shapes of pressure wavefronts in ducts after they have travelled sufficient distances to evolve to asymptotic states is introduced. Although it is possible in principle to achieve the same outcome by simulating complete flow histories from [...] Read more.
A novel method of determining the possible shapes of pressure wavefronts in ducts after they have travelled sufficient distances to evolve to asymptotic states is introduced. Although it is possible in principle to achieve the same outcome by simulating complete flow histories from the time of the creation of the wavefronts, this can be impracticable. It is especially unsuitable to use such methods when extremely small grid lengths are needed to represent the final outcome adequately. The new method does not simulate the propagation phase at all. Instead, it explores what final end states are possible, but gives no information about the initiating disturbance or the wavefront evolution towards the assessed asymptotic state. Accordingly, the two methods do not overlap, but instead are complementary to each other. A typical case in which the new capability has high potential is described and used to illustrate the purpose and use of the methodology. However, the primary focus is on the presentation and assessment of the method, not on any particular phenomenon. It is shown that the required computational resources are far smaller than those needed for conventional unsteady flow simulations of propagating wavefronts. The potential numerical limitations of the method are highlighted and, with one exception, are shown to be either of no consequence or easily reduced to acceptable levels. Special attention is paid to the one exception because it cannot be proven to be unimportant and, indeed, it would be unsafe to use it in general analyses of wave propagation. However, strong evidence is presented of its acceptability for the study of asymptotic wavefronts. Full article
(This article belongs to the Special Issue Modelling Flows in Pipes and Channels)
►▼ Show Figures

Figure 1

25 pages, 5876 KiB  
Article
Effects of Expelled Air during Filling Operations with Blocking Columns in Water Pipelines of Undulating Profiles
by Vicente S. Fuertes-Miquel, Oscar E. Coronado-Hernández and Alfonso Arrieta-Pastrana
Fluids 2024, 9(9), 212; https://doi.org/10.3390/fluids9090212 - 11 Sep 2024
Viewed by 655
Abstract
Entrapped air pockets can cause failure in water distribution systems if air valves have not been appropriately designed for expelling air during filling manoeuvres performed by water utilities. One-dimensional mathematical models recently developed for studying this phenomenon do not consider the effect of [...] Read more.
Entrapped air pockets can cause failure in water distribution systems if air valves have not been appropriately designed for expelling air during filling manoeuvres performed by water utilities. One-dimensional mathematical models recently developed for studying this phenomenon do not consider the effect of blocking columns inside water pipelines. This research presents the development of a mathematical model for analysing the filling process in a pipeline with an undulating profile with various air valves, including blocking columns during starting-up water installations. The results show how different air pocket pressure peaks can be produced over transient events, which need to be analysed to ensure a successful procedure that guarantees pipeline safety during the pressure surge occurrence. In this study, an experimental set-up is analysed to observe the behaviour of two blocking columns during filling by comparing the air pocket pressure pulses. Full article
(This article belongs to the Special Issue Modelling Flows in Pipes and Channels)
►▼ Show Figures

Figure 1

17 pages, 911 KiB  
Article
Turbulent Micropolar Open-Channel Flow
by George Sofiadis, Antonios Liakopoulos, Apostolos Palasis and Filippos Sofos
Fluids 2024, 9(9), 202; https://doi.org/10.3390/fluids9090202 - 31 Aug 2024
Viewed by 681
Abstract
The present paper focuses on the investigation of the turbulent characteristics of an open-channel flow by employing the micropolar model. The underlying model has already been proven to correctly describe the secondary phase of turbulent wall-bounded flows. The open-channel case comprises an ideal [...] Read more.
The present paper focuses on the investigation of the turbulent characteristics of an open-channel flow by employing the micropolar model. The underlying model has already been proven to correctly describe the secondary phase of turbulent wall-bounded flows. The open-channel case comprises an ideal candidate to further test the micropolar model as many environmental flows carry a secondary phase, the behavior of which is of great interest for applications such as sedimentation transport and debris flow. Direct Numerical Simulations (DNSs) have been carried out on an open channel for Reb = 11,200 based on mean crossectional velocity, channel height, and the fluid kinematic viscosity. The simulated results are compared against previous experimental as well as Langrangian DNS data of similar flows, with excellent agreement. The micropolar model is capable of describing the same problem but in an Eulerian frame, thus significantly simplifying the computational cost and complexity. Full article
(This article belongs to the Special Issue Modelling Flows in Pipes and Channels)
►▼ Show Figures

Figure 1

19 pages, 4859 KiB  
Article
Pressure and Velocity Profiles over a Weir Using Potential Flow Model
by M. R. Ajith Kumar, Prashanth R. Hanmaiahgari and Jaan H. Pu
Fluids 2024, 9(8), 182; https://doi.org/10.3390/fluids9080182 - 15 Aug 2024
Viewed by 1000
Abstract
A potential flow model of the semi-inverse type is proposed to simulate flow over round crested weirs. This technique involves the construction of only streamlines over the weir instead of constructing the entire flow net. A Serre–Green–Naghdi (SGN) equation is employed to determine [...] Read more.
A potential flow model of the semi-inverse type is proposed to simulate flow over round crested weirs. This technique involves the construction of only streamlines over the weir instead of constructing the entire flow net. A Serre–Green–Naghdi (SGN) equation is employed to determine the initial free-surface profile, which is solved using a combined finite volume-finite difference scheme. The potential flow equations were numerically solved using a five-point central finite difference scheme. The model was applied to define the pressure and velocity fields in channel controls involving transcritical flow, such as the Gaussian weir, parabolic weir, and semicircular weir. The impact of streamline curvature on pressure and velocity distributions was investigated in the study. The curvature of the streamline strongly influenced the rise and drop of the bed pressures along the test section. A semicircular weir experiment was also conducted to validate the pressure and velocity profiles obtained using the proposed 2-D fluid flow model. The computed pressure and flow profiles from the solution of the potential flow equation agree perfectly with the present experiment and similar experiments available in the literature. In conclusion, the SGN equation provides an excellent initial profile to solve a 2-D ideal fluid flow numerically. Full article
(This article belongs to the Special Issue Modelling Flows in Pipes and Channels)
►▼ Show Figures

Figure 1

19 pages, 6468 KiB  
Article
Minor Loss Coefficient for Abrupt Section Changes in a Cylindrical Pipe Using a Numerical Approach
by José González, Andrés Meana-Fernández, Iván Vallejo Pérez and Jesús M. Fernández Oro
Fluids 2024, 9(7), 152; https://doi.org/10.3390/fluids9070152 - 26 Jun 2024
Viewed by 1695
Abstract
Abrupt section changes are a classic problem in the study of flow in cylindrical ducts or pipes. For its analysis, there are a wide set of exiting data from previous studies, among which some authors stand out and will be mentioned. Those previous [...] Read more.
Abrupt section changes are a classic problem in the study of flow in cylindrical ducts or pipes. For its analysis, there are a wide set of exiting data from previous studies, among which some authors stand out and will be mentioned. Those previous works have been used to obtain reliable results for the resolution of section changes along a pipe, either due to cross area increases or reductions on a 1D basis. It is also known that a numerical 2D axisymmetric simulation (CFD) could find a consistent result compared to experimental data in almost all fluid flow fields. The main novelty of the present study is the development of a simple numerical approach used to solve the minor loss calculation. Firstly, a theoretical analysis is developed, and then the results of the numerical simulations carried out on the behavior that affects the water and air flow rate in an abrupt section change, for both contraction and expansion problems, are presented. In both cases, the results are analyzed with different meshes (discretizations) and turbulence models. Finally, the obtained numerical results are compared with those in the technical literature. Also, a theoretical approach is shown in order to show a whole frame of the discussion. The core results are the loss coefficient evolution as a function of the section change both for the sudden contraction and the expansion of a pipe flow. As the results follow the existing experimental values, it is concluded that the developed model provides a feasible and quick design tool to analyze possible geometrical changes without the need for further experiments. Full article
(This article belongs to the Special Issue Modelling Flows in Pipes and Channels)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-7
Back to TopTop