CFD Letters最新文献

{"title":"A comparative numerical study of three similar passive solar stills: Single slope, V-type, and greenhouse","authors":"Nguyen Van Dung, Nguyen Minh Phu, Nguyen Minh, Phu","doi":"10.37934/cfdl.16.1.6878","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.6878","url":null,"abstract":"In this paper, three solar stills with similar geometries are numerically investigated for analysis and comparison. The solar stills include single slope, V-type, and greenhouse stills. Steady-state laminar flow numerical simulations with different water surface temperatures and cover glass temperatures are performed. Simulation results were confirmed with data from analytical and experimental models to ensure reliability. The results showed that the V-type still has a higher number of recirculation zones than that of single slope and greenhouse stills. These vortex regions are small, but the velocity magnitude is no less than the other two stills. This difference makes the freshwater yield and convection heat transfer coefficient of V-type still the largest. Daily freshwater productions of single slope, V-type, and greenhouse stills are 0.592, 0.673, and 0.623 kg/m2, respectively. Productivity at 15 PM is 2.5 times higher than the hours from noon to 14 PM. The natural convection heat transfer coefficient seemed to be unvaried with the temperature difference but changed strongly with the still geometry.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"183 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139212627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CFD Analysis and Development of Mixing Tank Design for The Fermented Starch Production Process","authors":"Sigit Purwanto, Bayu Novariawan, Suparman, Palupi Tri Widiyanti, Isnaini Pratiwiningrum, Fitri Nur Kayati","doi":"10.37934/cfdl.16.1.95106","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.95106","url":null,"abstract":"Stirred tanks are widely used in the industrial world, design and improvements are still being developed, including the stirred fermenter tank. A numerical study was carried out to examine the relationship between experimental and reference and computational analysis, in order to minimize the power consumption of a stirred fermenter tanks and optimize the velocity distribution and its profile in radial and axial direction. Specifically, velocity distribution profile in radial and axial direction and the profile of pressure distribution of an experimental impeller, a flat impeller, and a flat-hole impeller were investigated using Computational Fluid Dynamic (CFD) analysis. It was found that the axial velocity at the top and the bottom of the experimental impeller was highly disparate at around 0.95 m/s, while the flat impeller and the flat-hole impeller experienced a disparity of 0.05 m/s and 0.21 m/s, respectively. In case terms of decreased power, the experimental impeller showed power reduction of 21%, greater than that of the flat-hole impeller configuration of 17%.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139214666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficiency Improvement of Double Pipe Heat Exchanger by using TiO2/water Nanofluid","authors":"Diyar F. Hussein, Yaser Alaiwi","doi":"10.37934/cfdl.16.1.4354","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.4354","url":null,"abstract":"Heat exchangers are commonly utilized to transfer heat between two fluids in a number of industries. However, parameters such as fluid flow velocity, temperature difference, and thermal conductivity limit their efficiency. Researchers have investigated the use of nanofluids - fluids containing nanoparticles that boost thermal characteristics - to improve the performance of heat exchangers. The use of nanofluids can improve the efficiency of double-pipe heat exchangers. However, research on the influence of TiO2/water nanofluid on the performance of double-pipe heat exchangers is insufficient. The purpose of this research is to investigate the impact of TiO2/water nanofluid on the efficiency of a double-pipe copper counter-flow heat exchanger. A double-pipe copper counter-flow heat exchanger using cold (room temperature) and hot (70°C) water as working fluids was used in an experimental investigation. They created nanofluids by adding varying concentrations (0.1%, 0.3%, and 0.5%) of TiO2 nanoparticles to water and measuring their heat conductivity and viscosity. They then calculated the overall heat transfer coefficient and efficacy by measuring the input and outlet temperatures as well as the flow rates of both fluids. It was discovered that adding TiO2 nanoparticles to water enhanced its heat conductivity and viscosity substantially. The overall heat transfer coefficient increased up to 0.3% but declined at 0.5% nanoparticle concentration. At a nanoparticle concentration of 0.3%, the maximum effectiveness was attained, with a corresponding increase in efficiency of up to 23%. The scientists found that using TiO2/water nanofluid to improve the efficiency of double-pipe heat exchangers is a viable option.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139214696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The The Effect of Sail Layout on Fishing Vessels Hydrodynamics in The North Coast of Java Using Computational Fluids Dynamic","authors":"Arif Winarno, Agung Sugeng Widodo, Gatot Ciptadi, Atiek Iriany","doi":"10.37934/cfdl.16.1.107120","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.107120","url":null,"abstract":"The fisheries sector is one of the potential sectors that contribute to Indonesia's state income, but it has often been neglected. Almost all fishing boats still use diesel engines as the main power source to propel the boat. The use of this type of fuel has an impact on increasing the level of air pollution such as CO2, SO2, and NOX in the atmosphere. However, research to reduce ship pollution, especially the combination of propulsion system for fishing boats using engines and sails, is rarely carried out. This study aims to determine the hydrodynamic characteristics of fishing vessels on the north coast of Java due to the application of numerical variations in laying sails using Computational Fluids Dynamics (CFD). The numerical simulation results show that the placement of sails in each model variation results in a change in the fluid flow pattern from bow to stern which can contribute to fuel efficiency. From the comparison of the three models, the most effective placement of sails is at the bow of the ship.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139211428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CFD Analysis in the Mesh Modified Gas Diffusion Layer of a Proton Exchange Membrane Fuel Cell (PEMFC)","authors":"Blandy Berenice Pamplona Solis, Julio César Cruz Argüello, Isaias May Canche, Leopoldo Gómez Barba, Mayra Polett Gurrola","doi":"10.37934/cfdl.16.1.5567","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.5567","url":null,"abstract":"Computational Fluid Dynamics (CFD) software is well known for its application feasibility as well as reliable results in modeling electrochemical, thermal, and fluid transport processes. CFD has been used to investigate the phenomena involved in the operation of fuel cells, providing a large amount of data that must be analyzed to improve cell efficiency. This paper aims to demonstrate that programming can be used in the post-processing phase, using scripts in Python language to automate data analysis, based on the results of the simulation of oxygen transport in Polymer Electrolyte Membrane Fuel Cell (PEMFC). The OpenFOAM open-source CFD tool solved the fluid governing equations through the SIMPLE algorithm of three proposed Gas Diffusion Layer (GDL) case studies. In this work, an algorithm is presented to extract, compute and visualize the post-process results, supporting the GDL selection.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139212590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CFD Analysis of Pure Waterjet Nozzle for Fruit Peeling and Cutting Process","authors":"Yaghthiswara Seran, Muhamad Safwan, Muhamad Azmi, Abdul Halim, Kamarulzaman Kamarudin, Lam Chee Kiang, Norasmadi Abdul Rahim, W. M. Nooriman, W. Yahya, Tan Kian Yew, Lum Wei, Min","doi":"10.37934/cfdl.16.1.138149","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.138149","url":null,"abstract":"Waterjet Technology has been used vastly in our world nowadays due to its advantages and it can be implemented in many industrial sectors or even in the medical sector and food industry sector. Nozzle is a component that has been utilized in waterjet which is employed in a wide range of engineering applications to control the rate of flow, velocity, and the jet pressure of the water. This paper discusses the CFD analysis on a pure waterjet nozzle to obtain the output of the water that jets out from three different diameters of nozzle and select the effective nozzle diameter to be used for the fruit peeling and cutting process. The pressure used for the analysis are 200MPa, 300MPa and 400MPa, which was analysed for three different nozzle diameter 0.76mm, 1.02mm and 1.27mm. From CFD analysis, it is established that as the pressure loss of the water jet increases, the outlet velocity of the jet increases. Furthermore, for fruit peeling and cutting process the impact angle of the nozzle should be prioritised as the peeling of the fruit should be smooth and even before cutting the fruit. Thus, the most suitable parameters were found to be 400MPa and 1.02mm of pressure and nozzle diameter respectively. This will allow for the intended fruit cutting process with a stand-off distance that can be ranged from 1mm to 9mm.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139213665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concept of Computational Fluid Dynamics and Its Application in Sport Science: Bibliometric Analysis of Modelling Thermal Comfort in Sport Hall","authors":"Boby Rachmat, Kristi Agust, Nur Indri Rahayu, M. Muktiarni, Tomoliyus","doi":"10.37934/cfdl.16.1.121","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.121","url":null,"abstract":"Computational Fluid Dynamics (CFD) has become a very effective tool in modeling and analyzing various complex phenomena, including being an integral part of analyzing thermal comfort phenomena. Therefore, this research was carried out to identify developments in the scientific literature related to research on sports science to carry out initial identification of sports hall thermal comfort modeling using dynamic computing concepts, analyzing trends and research focus in this field through bibliometrics. In addition, this research provides a comprehensive insight into the latest scientific contributions and developments in the field of sports science as an initial identification of sports hall thermal comfort modeling using a dynamic computing approach. Bibliometric analysis and theoretical analysis were chosen as research methods. This research also consists of five steps, namely (i) determining the theme and sources of research data; (ii) article data collection; (iii) data processing, (iv) bibliometric analysis, and (v) report preparation. \"Computational Fluid Dynamics Design (CFD) in Sport Science\" was used as a keyword in this research. Based on the search results, 823 documents were obtained from 1996 to 2023. Research on CFD in sports science will increase in 2022. Many countries, affiliates, and authors have contributed to increasing the number of publications on CFD in sports science, such as the United States with a total of 103 publications. With this research, it is hoped that it will provide insight to researchers, practitioners, and policymakers regarding research directions that may not have been fully explored in the application of CFD in the field of sports in particular, as well as other fields.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139213787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Fluid Dynamics: Flow Analysis on The Effect of Different Jet Orifice Angle Multi Circular Jet for Fuel and Air Mixing","authors":"Ridzwan Kamaruddin, Syabillah Sulaiman, Amir Khalid, Mr. Arafat, Norrizam Jaat, Shaiful Fadzil Zainal Abidin, Norirda Mohamed, Mohd Fuad Yasak","doi":"10.37934/cfdl.16.1.121137","DOIUrl":"https://doi.org/10.37934/cfdl.16.1.121137","url":null,"abstract":"The mixing of fuel and air plays a major role in the spray and flame behavior, hence affecting the combustion performance and emissions of the internal mixing air-assisted atomizers. Air-assisted atomizers are introduced to counter the low-pressure differential of a simplex nozzle, which reduces the atomization quality. The present study aims to determine the effects of Multi Circular Jet (MCJ) plates on the geometrical configurations of internal flows in mixing chamber and the internal flow of plate 3 using different properties of fuel. In this study, the realizable k-ε turbulence model, specifically designed for strongly swirling flows, is validated through numerical simulations. The turbulence model selected is a type of Reynolds averaged Navier-Stokes (RANS) model called the k-ε model. The MCJ plates provide the primary air entrance into the mixing chamber. Additionally, it acts as a turbulence generator and can be adjusted to alter the flow of fuel and air mixtures in a mixing chamber. The study compares several MCJ geometries in terms of pressure, speed, turbulent kinetic energy, and volume fraction and compares the performances of diesel and Crude Palm Oil (CPO) B30 biodiesel fuels. The findings imply that CPO B30 biodiesel has superior atomization and mixing due to its higher density and turbulent kinetic energy. CPO B30 biodiesel was compared to Diesel in terms of maximum pressure, average speed, turbulent kinetic energy per unit mass, and volume fraction. The results indicate that CPO B30 has lower pressure and higher velocity than Diesel, suggesting better fuel atomization and mixing. The higher density of CPO B30 leads to increased turbulent kinetic energy, improving fuel-air mixing inside the combustion chamber. The study demonstrates that the use of MCJ plates can enhance mixing in a mixing chamber. In addition, MCJ plates show the ability to control the spray and atomization. The findings of this study contribute to a better understanding of the relationships between geometry and fuel-air mixing, as well as the characteristics of the internal mixing air-assisted atomizer, which will lead to future burner system improvements.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139213092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi- Analytical Study on Non-Isothermal Steady R-D Equation in a Spherical Catalyst and Biocatalyst","authors":"None V. Vijayalakshmi, None V. Ananthaswamy, None J. Anantha Jothi","doi":"10.37934/cfdl.15.12.6076","DOIUrl":"https://doi.org/10.37934/cfdl.15.12.6076","url":null,"abstract":"The Lane-Emden Boundary Value Problem as it appears in chemical applications, science, and biochemical applications are employed. Two specific models are solved by applying the Ananthaswamy-Sivasankari method (ASM). The model in first problem is a reaction–diffusion equation of a spherical catalyst and the model in second problem is the reaction–diffusion process of a spherical biocatalyst. Obtain a reliable semi-analytical expression of the effectiveness factors and the concentrations. A graph is constructed for the obtained semi-analytical solutions.The effects of several parameters like dimensionless activation energy, Thiele modulus and dimensionless heat of reaction are shown in graphical representation. Our semi-analytical solution is compared with numerical simulation by using MATLAB and finds good fit in all parameters. The new analytical method ASM is helpful to solve many non-linear problems mainly Reaction-Diffusion equation.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136019302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Sloshing in Different Tank Shapes using Smoothed Particle Hydrodynamics","authors":"None Andi Trimulyono, None Suci Utami, None Deddy Chrismianto, None Parlindungan Manik","doi":"10.37934/cfdl.15.12.1933","DOIUrl":"https://doi.org/10.37934/cfdl.15.12.1933","url":null,"abstract":"Sloshing is the violent motion of a resonant fluid in a moving tank; when the fluid moves and interacts with the tank, the dynamic pressure from such an interaction can cause large fluid deformations with tank walls. In this study, a 3D numerical simulation of sloshing was carried out with five variations of the tank model, i.e., prismatic, rectangular, tube, spherical, and the new model tank with a filling ratio of 25% and 50%. Forced oscillation motion in a roll used frequencies 1.04 Hz and 1.34 Hz. The amplitude of movement was 8.66°. One pressure sensor was used to measure dynamic pressure in the mid of the tank. Because sloshing deals with large deformation and discontinuities, the particle method was suitable for the application. This study used smoothed particle hydrodynamics based on weakly compressible SPH (WCSPH). SPH is a Lagrangian meshless method known as mesh-free computational fluid dynamics. Open-source SPH solver version 5.0 was used to reproduce sloshing in different tank shapes; in addition, advanced visualization was performed using the VisualSPHysics add-on in Blender version 2.92. The sloshing visualization is more realistic and attractive than conventional SPH post-processing. The results of this study indicate that different tank shapes influence reducing the value of dynamic pressure and hydrodynamic force. It is found that a practical tank shape is a tube tank and a new model tank with a reduced dynamic pressure value of 9% and 11% and a reduced hydrodynamic force value of 36% and 48%.","PeriodicalId":9736,"journal":{"name":"CFD Letters","volume":"5 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136103990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}