Editorial

6 pages, 211 KiB

Open AccessEditorial

Recent Advances in Fluid Mechanics and Transport Phenomena

by Shyy Woei Chang

Inventions 2023, 8(6), 136; https://doi.org/10.3390/inventions8060136 - 27 Oct 2023

Viewed by 1380

Transport phenomena draw from the fields of continuum mechanics and thermodynamics with diverse industrial applications [...] Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

Research

Jump to: Editorial

19 pages, 6629 KiB

Open AccessArticle

Experimental Validation of the Numerical Model for Oil–Gas Separation

by Sorin Gabriel Tomescu, Ion Mălăel, Rareș Conțiu and Sebastian Voicu

Inventions 2023, 8(5), 125; https://doi.org/10.3390/inventions8050125 - 10 Oct 2023

Cited by 1 | Viewed by 1504

Abstract

The oil and gas sector is important to the global economy because it covers the exploration, production, processing, transportation, and distribution of oil and natural gas resources. Despite constant innovation and development of technologies to improve efficiency, reduce environmental impact, and optimize operations [...] Read more.

The oil and gas sector is important to the global economy because it covers the exploration, production, processing, transportation, and distribution of oil and natural gas resources. Despite constant innovation and development of technologies to improve efficiency, reduce environmental impact, and optimize operations in the gas and oil industry over the last few decades, there is still room to increase the efficiency of the industry’s equipment in order to reduce its carbon footprint. The separation of gas from oil is a critical stage in the technological production chain, and it is carried out using high-performance multi-phase separators to limit greenhouse gas emissions and have a low impact on the environment. In this study, an improved gas–oil separator configuration was established utilizing CFD techniques. Two separator geometry characteristics were studied. Both cases have the same number of subdomains, two porous media, and four fluid zones, but with a difference in the pitch of the cyclone from the inlet subdomain. The streamlines in a cross-plan of the separator and the distribution of the oil volume fraction from the intake to the outlet were two of the numerical results that were shown as numeric outcomes. The validation of these results was performed using an experimental testing campaign that had the purpose of determining the amount of lubricating oil that is discharged together with the compressed gas at the separator outlet. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

15 pages, 6204 KiB

Open AccessArticle

Design and Construction of a Device to Evaluate the Performance of Variable Orifice Flow Meters (VOFM)

by William Prado Martínez, Juan Felipe Arroyave Londoño and Jefferson Vásquez Gómez

Inventions 2023, 8(5), 110; https://doi.org/10.3390/inventions8050110 - 30 Aug 2023

Cited by 1 | Viewed by 1200

Abstract

This work presents a low-cost device for evaluating Variable Orifice Flow Meters (VOFM) used in medical mechanical ventilation applications. Specifically, the equipment was used to assess the impact of length and thickness on pressure drop for different flows in a rectangular geometry VOFM. [...] Read more.

This work presents a low-cost device for evaluating Variable Orifice Flow Meters (VOFM) used in medical mechanical ventilation applications. Specifically, the equipment was used to assess the impact of length and thickness on pressure drop for different flows in a rectangular geometry VOFM. A total of six VOFMs, with three different lengths and two different thicknesses, were evaluated. All VOFMs were stimulated with an airflow ranging from 0

L . {m i n}^{- 1}

to 90

L . {m i n}^{- 1}

, with increments of approximately 2

L . {m i n}^{- 1}

. The experiments conducted with the device showed a strong relationship between pressure drop

∆ P

and flow rate

Q

in the evaluated VOFMs, with two different zones: one exhibiting non-linear behavior and another showing linear behavior. The results suggest that increased length and decreased thickness lead to higher sensitivity. However, it is essential to reduce the cross-sectional area to mitigate nonlinear effects of the sensor. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

20 pages, 6504 KiB

Open AccessArticle

Thermal Convection in a Heated-Block Duct with Periodic Boundary Conditions by Element-by-Element Treatment

by Tswen-Chyuan Jue, Horng-Wen Wu, Ying-Chien Hsueh and Zhi-Wei Guo

Inventions 2023, 8(4), 97; https://doi.org/10.3390/inventions8040097 - 26 Jul 2023

Viewed by 925

Abstract

The periodic nature of stream-wise flow occurs in a cooling channel so frequently due to the multiple heat sources in electronic equipment, demanding the creation of an effective technique to improve the heat-cooling convection. This work explores thermal convection enhancement in a heated-block [...] Read more.

The periodic nature of stream-wise flow occurs in a cooling channel so frequently due to the multiple heat sources in electronic equipment, demanding the creation of an effective technique to improve the heat-cooling convection. This work explores thermal convection enhancement in a heated-block duct for periodic boundary conditions using the element-by-element (EBE) treatment in a semi-implicit projection finite element method (FEM) through a preconditioned conjugate gradient (PCG) solver. The effects of changing the Reynolds numbers (100, 175, and 250) on rectangular cylinders installed in the channel under periodic boundary conditions were studied using time-mean Nusselt number enhancement, friction factor enhancement, and thermal performance coefficient. The results show that the rectangular cylinders installed stream-wise above an upstream block promote thermal convection in the heated-block duct due to modifying the flow of no cylinders. However, increasing the number of rectangular cylinders increases the friction factor enhancement. As a result, the case for periodic boundary conditions with a rectangular cylinder above every two blocks has the best thermal performance coefficient. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

20 pages, 7424 KiB

Open AccessArticle

Validation of a Simplified Numerical Model for Predicting Solid–Liquid Phase Change with Natural Convection in Ansys CFX

by Nuno Rosa, Nelson Soares, José Costa and António Gameiro Lopes

Inventions 2023, 8(4), 93; https://doi.org/10.3390/inventions8040093 - 20 Jul 2023

Cited by 1 | Viewed by 1200

Abstract

This paper presents a numerical model for simulating melting and solidification driven by natural convection, and validates it against a previous experiment. The experiment involved filling a rectangular aluminum enclosure with RT28HC Phase Change Material (PCM) to 95% of its capacity. To investigate [...] Read more.

This paper presents a numerical model for simulating melting and solidification driven by natural convection, and validates it against a previous experiment. The experiment involved filling a rectangular aluminum enclosure with RT28HC Phase Change Material (PCM) to 95% of its capacity. To investigate the thermal behavior of the PCM during phase change, the enclosure underwent independent heating and cooling procedures. The simulation was conducted using ANSYS CFX^®, and the additional heat source (AHS) method was implemented in conjunction with the Boussinesq approximation to account for the latent heat during melting and solidification driven by natural convection. This allowed the calculation of temperature fields, the melted fraction, and fluid dynamics during phase change. The momentum equations were modified to include a source term that accounted for a gradual decrease in fluid velocity as the PCM transitions from solid to liquid. To account for density variation, an artificial specific heat curve was implemented based on the assumption that the product of density and specific heat remains constant during phase change. The proposed numerical model achieved good agreement with the experimental data, with an average root mean square error of 2.6% and 3.7% for temperature profiles during charging and discharging simulations, respectively. This model can be easily implemented in ANSYS CFX^® and accurately predicts charging and discharging kinetics, as well as stored/released energy, without any numerical convergence issues. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

10 pages, 3077 KiB

Open AccessCommunication

Whole-Body Cryostimulation: New Insights in Thermo-Aeraulic Fields inside Chambers

by Rim Elfahem, Boussad Abbes, Bastien Bouchet, Sebastien Murer, Fabien Bogard, Tala Moussa, Fabien Beaumont and Guillaume Polidori

Inventions 2023, 8(4), 81; https://doi.org/10.3390/inventions8040081 - 24 Jun 2023

Cited by 2 | Viewed by 831

Abstract

(1) Background: This article presents a study that aims to provide a precise understanding of the temperature distribution within a whole-body cryostimulation (WBC) chamber, whether it is empty or occupied by one or several individuals; (2) Methods: The study employs a mixed numerical [...] Read more.

(1) Background: This article presents a study that aims to provide a precise understanding of the temperature distribution within a whole-body cryostimulation (WBC) chamber, whether it is empty or occupied by one or several individuals; (2) Methods: The study employs a mixed numerical and experimental approach, utilizing simplified computational fluid dynamics (CFD) simulations and experimental analysis; (3) Results: The results reveal a non-negligible temperature difference between the setpoint and actual temperature in the middle of the cryochamber. Furthermore, it is shown that the presence of individuals inside the chamber results in both an average temperature rise and a more heterogeneous thermal behavior associated with the number of individuals present. As the number of occupants in the cryochamber increases, the magnitude of the thermal gradient (up to 10 °C) and temperature heterogeneity (up to 13%) also increase; (4) Conclusions: The results suggest that when the cryotherapy chamber is occupied by three people, it becomes necessary to extend the duration of cold exposure to obtain a dose/effect ratio and analgesic threshold equivalent to those obtained when only one person is present. The findings of this study emphasize the need for further research to establish temperature guidelines and standardize measurement methods for effective WBC treatment. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

27 pages, 9187 KiB

Open AccessArticle

CFD Investigation for Sonar Dome with Bulbous Bow Effect

by Ping-Chen Wu, Jiun-Yu Chen, Chen-I Wu and Jiun-Ting Lin

Inventions 2023, 8(2), 58; https://doi.org/10.3390/inventions8020058 - 23 Mar 2023

Viewed by 1905

Abstract

The objective of this study is to design a hull-mounted sonar dome of a ship using OpenFOAM with a bulbous bow effect at cruise speed in calm water. Verification and validation for the original sonar dome simulation are conducted. Next, the 1.44 million [...] Read more.

The objective of this study is to design a hull-mounted sonar dome of a ship using OpenFOAM with a bulbous bow effect at cruise speed in calm water. Verification and validation for the original sonar dome simulation are conducted. Next, the 1.44 million grid size is selected to study different dome lengths. By protruding the dome forward 7.5% of the ship’s length, the optimal 17% resistance reduction is achieved and is mainly caused by the pressure resistance decrease. The optimal sonar dome not only functions in the same way as a bulbous bow, but the viscous flow behaviors are also improved. The protrusion corresponding to 90 deg phase lag reduces the bow wave amplitude. The flow acceleration outside the boundary layer and ship wake velocity are higher coinciding with the much lower total resistance. A smaller flow separation and thinner boundary layer are also observed behind the sonar dome because its back slope is less steep. The high pressure covers a smaller area around the bow, and the smaller bow wave crest does not hit the ship’s flare to form high pressure. Consequently, the lower high pressure on the dome front and higher low pressure on the dome back result in the decreases in pressure resistance. The vortical structures are also improved. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

16 pages, 1034 KiB

Open AccessArticle

On Some Theoretical Aspects of The Evaporation Process of a Droplet and Its Optimal Size When Extinguishing Fires

by Sergey Oktyabrinovich Gladkov

Inventions 2023, 8(1), 35; https://doi.org/10.3390/inventions8010035 - 30 Jan 2023

Cited by 1 | Viewed by 924

Abstract

We are proposing a model mathematical description of droplet evaporation using the kinetic approach. We have obtained the basic equation of the theory by using the law of conserving the full power of the vapor–liquid system, which has not been done before. We [...] Read more.

We are proposing a model mathematical description of droplet evaporation using the kinetic approach. We have obtained the basic equation of the theory by using the law of conserving the full power of the vapor–liquid system, which has not been done before. We have found the range of droplet sizes at which it is stable. We have given a comparison of the obtained results with the known traditional ones. We have given numerical estimates for the critical size of the fine-dispersed phase up to the value of which ordinary evaporation takes place (that is for Knudsen number

K n = \frac{l}{R}

, inequality

K n ≪ 1

must be fulfilled, where

l -

is the free path of the molecule and

R -

is the droplet radius). We have given the optimal droplet size which is the most effective from the point of view of technical use in extinguishing flammable oil transformers. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

14 pages, 3715 KiB

Open AccessArticle

Modification of Pulse Decay Method for Determination of Permeability of Crystalline Rocks

by Victor I. Malkovsky, Andrey V. Zharikov and Michael I. Ojovan

Inventions 2023, 8(1), 14; https://doi.org/10.3390/inventions8010014 - 06 Jan 2023

Viewed by 1345

Abstract

An improvement of the pulse decay method of rock permeability measurement is presented. The technique is based on fitting experimental data to analytical and numerical solutions of the filtration equations derived with regard to the variation of flowing gas properties with temperature and [...] Read more.

An improvement of the pulse decay method of rock permeability measurement is presented. The technique is based on fitting experimental data to analytical and numerical solutions of the filtration equations derived with regard to the variation of flowing gas properties with temperature and pressure. A special apparatus and software for the implementation of this method were developed. A single experiment in which gas is used as a flowing medium enables determining both the permeability of a sample to water and the Klinkenberg constant. The permeability measurements on the samples of different types of rock with various reservoir properties were carried out and demonstrated satisfactory accuracy and efficiency of the method. An effective method for anisotropic permeability measurement is proposed as a development of this technique. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

17 pages, 5096 KiB

Open AccessArticle

An Original Aerodynamic Ducting System to Improve Energy Efficiency in the Automotive Industry

by Jana Fernández-Gutiérrez, Pablo Fernández-Arias, Diego Vergara and Álvaro Antón-Sancho

Inventions 2023, 8(1), 13; https://doi.org/10.3390/inventions8010013 - 06 Jan 2023

Cited by 1 | Viewed by 1977

Abstract

In the automotive industry, the flow of air generates high resistance in the advance of vehicles. In light of this situation, the objective of the present invention is to take advantage of the force of the air itself to help propel vehicles and [...] Read more.

In the automotive industry, the flow of air generates high resistance in the advance of vehicles. In light of this situation, the objective of the present invention is to take advantage of the force of the air itself to help propel vehicles and thus reduce fuel consumption. A channeling system has been designed based on a deflector that collects the air that impacts against the vehicle at the front, transferring it to the rear where it is expelled, allowing the vacuum zone to be filled so that the high pressures of the channeled air are repositioned in the depression zone, significantly increasing the values of the pressures, including those that were previously negative. The deflector has been built and incorporated into a model car so that comparative experimental wind tunnel tests could be carried out to verify that the vacuum in the rear area is eliminated, and positive pressure is obtained. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

17 pages, 2872 KiB

Open AccessArticle

Research and Development of Criterial Correlations for the Optimal Grid Element Size Used for RANS Flow Simulation in Single and Compound Channels

by Pavel Bryzgunov, Sergey Osipov, Ivan Komarov, Andrey Rogalev and Nikolay Rogalev

Inventions 2023, 8(1), 4; https://doi.org/10.3390/inventions8010004 - 23 Dec 2022

Viewed by 1475

Abstract

At present, software products for numerical simulation of fluid dynamics problems (ANSYS Fluent, Ansys CFX, Star CCM, Comsol, etc.) problems are widely used. These software products are mainly based on the numerical solution of the Navier–Stokes equations, the most common and computationally easy [...] Read more.

At present, software products for numerical simulation of fluid dynamics problems (ANSYS Fluent, Ansys CFX, Star CCM, Comsol, etc.) problems are widely used. These software products are mainly based on the numerical solution of the Navier–Stokes equations, the most common and computationally easy method of solving, which is Reynolds averaging (RANS), and further closing the system using semi-empirical turbulence models. Currently, there are many modeling methods and turbulence models; however, there are no generalized recommendations for setting up grid models for modeling flows, while for practical use both the correct mathematical models and the setting of the computational grid are important. In particular, there are no generalized recommendations on the choice of scale of global elements of grid models for typical single channels. This work is devoted to the development and study of relations for a priori estimation of the parameters of a grid model in relation to solving hydrodynamic problems with fluid flow in channels. The paper proposes the introduction of a generalized grid convergence criterion for single channels at high Reynolds numbers. As single channels, a channel with a sudden expansion, a channel with a sudden contraction, and diffuser channels with different opening angles are considered. Based on the results of variant calculations of typical single channels at various Reynolds numbers and various geometric parameters, generalized criterion correlations were obtained to find dimensionless linear scales of grid elements relative to the hydrodynamic characteristics of the flow in the channel. Variant calculations of the compound channel were investigated, which showed the adequacy of correlations proposed. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

20 pages, 9396 KiB

Open AccessArticle

Aerodynamic Performance of a Horizontal Axis Wind Turbine Operating with Dust—A Computational Study

by Dimitra Douvi, Eleni Douvi and Dionissios Margaris

Inventions 2023, 8(1), 3; https://doi.org/10.3390/inventions8010003 - 23 Dec 2022

Cited by 2 | Viewed by 2423

Abstract

The main purpose of this study is to develop an understanding of the aerodynamic performance of a horizontal axis wind turbine (HAWT) operating in a dusty environment, with various concentration of dust in the flow domain. The computational analysis was accomplished by the [...] Read more.

The main purpose of this study is to develop an understanding of the aerodynamic performance of a horizontal axis wind turbine (HAWT) operating in a dusty environment, with various concentration of dust in the flow domain. The computational analysis was accomplished by the commercial computational fluid dynamics (CFD) code ANSYS Fluent 16.0. Initially, a user-friendly developed application was utilized for the optimum blade geometry special characteristics calculation. The design of the HAWT rotor and meshing of the computational domain follows. The moving reference frame (MRF) model was applied for the rotary motion of the blades, the dust was added in the computational domain by the discrete phase model (DPM) and SST k–ω turbulence model was enabled. The power output of the studied HAWT, operating in several dusty environments, was estimated and compared with the power output of a particular HAWT in clean air. The flow field around the HAWT rotor, including the contours of pressure, particles dissipation rate and erosion rate on both blade sides, are shown. In general, it is concluded that the operation of a HAWT in a dusty environment results in degraded performance, due to the particles deposition on the blades. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Mechanics and Transport Phenomena)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Recent Advances in Fluid Mechanics and Transport Phenomena

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (12 papers)

Editorial

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI