Juan Carlos Ojeda Toro, I. Dobrosz-Gómez, Miguel Ángel Gómez García
Acetyl chloride hydrolysis is a highly sensitive exothermic reaction that has presented several industrial safety issues. In the present study, a multiparameter mathematical model, previously developed and applied to simulate the oscillatory thermal behavior of an experimental continuous stirred tank reactor, was used to determine the static/dynamic bifurcation behavior of this reactive system. The values predicted by the model showed good agreement with the experimental data reported in the literature. Full topological classification of its fixed points and iterative maps was obtained: unique solutions (stable and unstable), multiple solutions, cyclic envelope, and bifurcation objects of codimension 1 (e.g., fold and Hopf’s points) and codimension 2 (e.g., cusp and generalized Hopf and Bogdanov-Takens points) have been uncovered. The emphasis of the analysis is to determine safe operating conditions through understanding these topological features and manipulating the reactor design and operating parameters.
{"title":"Setting Safe Operation Conditions for Acetyl Chloride Hydrolysis through Dynamic Modelling and Bifurcation Analysis","authors":"Juan Carlos Ojeda Toro, I. Dobrosz-Gómez, Miguel Ángel Gómez García","doi":"10.1155/2023/9685811","DOIUrl":"https://doi.org/10.1155/2023/9685811","url":null,"abstract":"Acetyl chloride hydrolysis is a highly sensitive exothermic reaction that has presented several industrial safety issues. In the present study, a multiparameter mathematical model, previously developed and applied to simulate the oscillatory thermal behavior of an experimental continuous stirred tank reactor, was used to determine the static/dynamic bifurcation behavior of this reactive system. The values predicted by the model showed good agreement with the experimental data reported in the literature. Full topological classification of its fixed points and iterative maps was obtained: unique solutions (stable and unstable), multiple solutions, cyclic envelope, and bifurcation objects of codimension 1 (e.g., fold and Hopf’s points) and codimension 2 (e.g., cusp and generalized Hopf and Bogdanov-Takens points) have been uncovered. The emphasis of the analysis is to determine safe operating conditions through understanding these topological features and manipulating the reactor design and operating parameters.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"5 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139261622","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}
In this study, CFD simulations that incorporate the inherent coupling between the moisture content of the mushroom and hot air flow in the tray dryer were performed. Conservation principles were applied to the fundamental quantities of mass, momentum, and heat. The source terms due to the moisture evaporation, the viscous and inertial resistance, and continuous evaporative cooling were determined through experimental results. Experiments were conducted to study and select the drying kinetics model at the optimum drying conditions and moisture sorption isotherm model at 30, 40, and 50°C temperatures. The best model describing the drying kinetics of mushrooms and moisture sorption isotherm model was chosen based on the lowest RMSE values and the highest value. Midilli et al.’s drying kinetics model and the modified Henderson sorption isotherm model were adopted in CFD modelling. The CFD software ANSYS Fluent was used for the 3D modelling of mushroom drying in a tray dryer. The mass and energy source term equations were added to the ANSYS Fluent software using a user-defined function (UDF). The parameter permeability of medium ( ) and pressure-jump coefficient ( ) appearing in the momentum source term were directly introduced in the Fluent setup as cell zone conditions. The simulation results of the moisture removal and drying temperatures were validated against experimental data. Both results are in good agreement with the experimental data, with values of 0.9906 for moisture contents and 0.926 for drying temperature. Thus, simulation can be an option to study the drying mechanisms and alleviate some drawbacks of doing experiments.
{"title":"Mathematical-Based CFD Modelling and Simulation of Mushroom Drying in Tray Dryer","authors":"Talbachew Tadesse Nadew, Petros Demissie Tegenaw, Tsegaye Sissay Tedila","doi":"10.1155/2023/6128517","DOIUrl":"https://doi.org/10.1155/2023/6128517","url":null,"abstract":"In this study, CFD simulations that incorporate the inherent coupling between the moisture content of the mushroom and hot air flow in the tray dryer were performed. Conservation principles were applied to the fundamental quantities of mass, momentum, and heat. The source terms due to the moisture evaporation, the viscous and inertial resistance, and continuous evaporative cooling were determined through experimental results. Experiments were conducted to study and select the drying kinetics model at the optimum drying conditions and moisture sorption isotherm model at 30, 40, and 50°C temperatures. The best model describing the drying kinetics of mushrooms and moisture sorption isotherm model was chosen based on the lowest RMSE values and the highest <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"> <msup> <mrow> <mi>R</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msup> </math> value. Midilli et al.’s drying kinetics model and the modified Henderson sorption isotherm model were adopted in CFD modelling. The CFD software ANSYS Fluent was used for the 3D modelling of mushroom drying in a tray dryer. The mass and energy source term equations were added to the ANSYS Fluent software using a user-defined function (UDF). The parameter permeability of medium ( <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\"> <mi>α</mi> </math> ) and pressure-jump coefficient ( <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M3\"> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> </math> ) appearing in the momentum source term were directly introduced in the Fluent setup as cell zone conditions. The simulation results of the moisture removal and drying temperatures were validated against experimental data. Both results are in good agreement with the experimental data, with <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M4\"> <msup> <mrow> <mi>R</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msup> </math> values of 0.9906 for moisture contents and 0.926 for drying temperature. Thus, simulation can be an option to study the drying mechanisms and alleviate some drawbacks of doing experiments.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"58 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376618","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}
This paper assesses the transport system of Addis Ababa, Ethiopia, taking factors such as the number of vehicles, roadway width, speed of vehicles, longitudinal grade, and proportion of both fuel and electrical vehicles by dividing vehicles into seven classes, namely, car, minibus, small bus, coach, small truck, heavy truck, and truck trailer, to determine CO2 emission, CO emission fuel consumption, and electric consumption in addition to the percent to replace ICE vehicles. After selecting eight representative road sections in Addis Ababa city, input data was collected from both primary and secondary sources. Simulation of urban mobility (SUMO) is used to model the existing road transport system and two other scenarios, cases being 20% and 40% replacement of internal combustion engine vehicles by electric vehicles. Among the vehicle types studied under this paper, the SUMO results show that coaches are with the highest CO2 emission, releasing an average amount of 28.442 grams of CO2 every time step, while cars are with the lowest CO2 emission value of 6.542 grams. Minibuses are the top CO emitters, releasing an average of 0.420 grams of CO every time step, and truck trailers emit the smallest CO emission, 0.025 grams. Regarding electric consumption, the truck trailer is the vehicle type with the highest electric consumption, with a value of 2.282 kwh (watthour) consumption every time step, and cars are the least electricity-consuming vehicles, with a value of 0.151 kwh. The fourth point is fuel consumption; besides the high CO2 emission, coaches’ consumption of fuel is leading by 8.946 grams, and cars use 2.087 grams of fuel every time step. Totally, public transport vehicles are responsible for higher emissions and huge fuel consumption. Therefore, if our transport system encourages the penetration of electric vehicles into the road transport system, a healthy and energy-efficient environment is reserved. Again, from a financial and environmental standpoint, the replacement of 40% of ICE vehicles by EVs enhances us with reduced costs and a green environment.
本文对埃塞俄比亚亚的斯亚贝巴的交通系统进行了评估，采用车辆数量、道路宽度、车辆速度、纵向坡度、燃油和电动汽车比例等因素，将车辆分为轿车、小巴、小巴、客车、小卡车、重型卡车和卡车挂车7类，确定二氧化碳排放量、CO排放燃料消耗和电力消耗，以及替代ICE车辆的百分比。在亚的斯亚贝巴市选择了八个具有代表性的路段后，从一级和二级来源收集了输入数据。城市交通模拟(SUMO)用于模拟现有的道路交通系统和其他两种情况，即20%和40%的内燃机汽车被电动汽车取代。在本文研究的车型中，SUMO结果表明，客车的CO2排放量最高，平均每步排放28.442 g CO2，而汽车的CO2排放量最低，为6.542 g。小巴的CO排放量最大，平均每步排放0.420克CO，卡车挂车的CO排放量最小，为0.025克。在耗电量方面，卡车挂车是耗电量最高的车型，每时间步耗电量为2.282 kwh(瓦时)，轿车是耗电量最少的车型，每时间步耗电量为0.151 kwh。第四点是油耗;除了二氧化碳排放量高外，客车的燃油消耗量也高达8.946 g，轿车每步油耗为2.087 g。总的来说，公共交通工具要为更高的排放和巨大的燃料消耗负责。因此，如果我们的交通系统鼓励电动汽车渗透到道路交通系统中，我们就保留了一个健康和节能的环境。同样，从财务和环境的角度来看，电动汽车取代40%的内燃机汽车可以降低成本，创造绿色环境。
{"title":"Evaluation of Electric Vehicle-Dependent Strategy in Addis Ababa, Ethiopia Transport System","authors":"Tesfamichael Chala Eticha, Yonas Minalu Emagnu","doi":"10.1155/2023/1874418","DOIUrl":"https://doi.org/10.1155/2023/1874418","url":null,"abstract":"This paper assesses the transport system of Addis Ababa, Ethiopia, taking factors such as the number of vehicles, roadway width, speed of vehicles, longitudinal grade, and proportion of both fuel and electrical vehicles by dividing vehicles into seven classes, namely, car, minibus, small bus, coach, small truck, heavy truck, and truck trailer, to determine CO2 emission, CO emission fuel consumption, and electric consumption in addition to the percent to replace ICE vehicles. After selecting eight representative road sections in Addis Ababa city, input data was collected from both primary and secondary sources. Simulation of urban mobility (SUMO) is used to model the existing road transport system and two other scenarios, cases being 20% and 40% replacement of internal combustion engine vehicles by electric vehicles. Among the vehicle types studied under this paper, the SUMO results show that coaches are with the highest CO2 emission, releasing an average amount of 28.442 grams of CO2 every time step, while cars are with the lowest CO2 emission value of 6.542 grams. Minibuses are the top CO emitters, releasing an average of 0.420 grams of CO every time step, and truck trailers emit the smallest CO emission, 0.025 grams. Regarding electric consumption, the truck trailer is the vehicle type with the highest electric consumption, with a value of 2.282 kwh (watthour) consumption every time step, and cars are the least electricity-consuming vehicles, with a value of 0.151 kwh. The fourth point is fuel consumption; besides the high CO2 emission, coaches’ consumption of fuel is leading by 8.946 grams, and cars use 2.087 grams of fuel every time step. Totally, public transport vehicles are responsible for higher emissions and huge fuel consumption. Therefore, if our transport system encourages the penetration of electric vehicles into the road transport system, a healthy and energy-efficient environment is reserved. Again, from a financial and environmental standpoint, the replacement of 40% of ICE vehicles by EVs enhances us with reduced costs and a green environment.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135254353","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}
The physiological mechanisms conduction, convection, and radiation exchange the heat energy in bi-directional routes between the body and the temperature field. Metabolism and evaporation are the uni-directional routes for the exchange of heat energy. In the metabolic process, the body creates internal heat energy, whereas the body loses excess heat energy through the evaporation process and maintains the body temperature. This study has shown steady and unsteady state temperature distribution in three skin layers: epidermis, dermis, and subcutaneous tissue, during walking and marathon. The results have analyzed that each skin layer temperature is higher during a marathon compared with walking due to more metabolic effects. The computation has been carried out for the two-dimensional Pennes’ bio-heat equation using a finite element approach. The generated results have been exhibited graphically.
{"title":"Two-Dimensional FEM Approach of Metabolic Effect on Thermoregulation in Human Dermal Parts During Walking and Marathon","authors":"D. Shrestha, S. Acharya, D. B. Gurung","doi":"10.1155/2023/5728385","DOIUrl":"https://doi.org/10.1155/2023/5728385","url":null,"abstract":"The physiological mechanisms conduction, convection, and radiation exchange the heat energy in bi-directional routes between the body and the temperature field. Metabolism and evaporation are the uni-directional routes for the exchange of heat energy. In the metabolic process, the body creates internal heat energy, whereas the body loses excess heat energy through the evaporation process and maintains the body temperature. This study has shown steady and unsteady state temperature distribution in three skin layers: epidermis, dermis, and subcutaneous tissue, during walking and marathon. The results have analyzed that each skin layer temperature is higher during a marathon compared with walking due to more metabolic effects. The computation has been carried out for the two-dimensional Pennes’ bio-heat equation using a finite element approach. The generated results have been exhibited graphically.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"28 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74104319","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}
Wire nets woven from high-strength steel wires have been used as applique armor against attack by short-range weapons. In this study, the mechanical behavior of chain-link wire nets under pressure from a warhead was investigated by quasistatic experiments and simulations. First, the new rig, the warhead device, and the wire nets were designed; pressure tests were conducted; and the deformation, fracture of the wire nets, and pressure force vs. displacement curves were obtained and analyzed. Then, the numerical approach and Finite element (FE) model were developed, considering the contacts between the steel wires in the inner connections, the contacts between the warhead and the mesh of the wire nets, and the fracture of the steel wire material. By comparison with the experimental data, the numerical approach and FE model are shown to be reliable in predicting the behavior of the wire nets under pressure from a warhead. Finally, the parameters of the wire net size and the mesh angles were further investigated by using the validated numerical approach and FE model, and suggestions for the initial design of the wire nets are discussed.
{"title":"Mechanical Behavior of Chain-Link Wire Nets under Pressure from a Warhead: Quasistatic Experiments and Simulations","authors":"Min Wang, Shuai Zhou, Qilin Huang","doi":"10.1155/2023/9655548","DOIUrl":"https://doi.org/10.1155/2023/9655548","url":null,"abstract":"Wire nets woven from high-strength steel wires have been used as applique armor against attack by short-range weapons. In this study, the mechanical behavior of chain-link wire nets under pressure from a warhead was investigated by quasistatic experiments and simulations. First, the new rig, the warhead device, and the wire nets were designed; pressure tests were conducted; and the deformation, fracture of the wire nets, and pressure force vs. displacement curves were obtained and analyzed. Then, the numerical approach and Finite element (FE) model were developed, considering the contacts between the steel wires in the inner connections, the contacts between the warhead and the mesh of the wire nets, and the fracture of the steel wire material. By comparison with the experimental data, the numerical approach and FE model are shown to be reliable in predicting the behavior of the wire nets under pressure from a warhead. Finally, the parameters of the wire net size and the mesh angles were further investigated by using the validated numerical approach and FE model, and suggestions for the initial design of the wire nets are discussed.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"16 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80213807","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}
C. Bao, Da Lv, Huxiang Wang, Yuhang Zhang, Xiaotong Ma, K. S. Lim, Juping Zhang
Corrosion causes reduction in cross-sectional area of reinforcement, deterioration of mechanical properties, and degradation of bonding properties between reinforced concrete, which are the most important factors leading to the degradation of structural service performance. In order to investigate the progressive collapse mechanism of a corroded reinforced concrete frame structure, the failure modes, characteristics of the vertical displacement, and load capacity are studied using the finite element method. Based on existing experimental research, the established model is verified, and the influence of different influencing factors on the progressive collapse mechanism is analyzed. The results show that the corrosion of the reinforcement affects the yield load, peak load, and ultimate load of the reinforced concrete substructure. As the corrosion rate increases, the tensile arch action shows a particularly severe deterioration. The variation of concrete strength and the height–span ratio affects the substructure’s load-bearing capacity much more significantly than the stirrup spacing.
{"title":"Progressive Collapse Resistance Mechanism of RC Frame Structure Considering Reinforcement Corrosion","authors":"C. Bao, Da Lv, Huxiang Wang, Yuhang Zhang, Xiaotong Ma, K. S. Lim, Juping Zhang","doi":"10.1155/2023/4451011","DOIUrl":"https://doi.org/10.1155/2023/4451011","url":null,"abstract":"Corrosion causes reduction in cross-sectional area of reinforcement, deterioration of mechanical properties, and degradation of bonding properties between reinforced concrete, which are the most important factors leading to the degradation of structural service performance. In order to investigate the progressive collapse mechanism of a corroded reinforced concrete frame structure, the failure modes, characteristics of the vertical displacement, and load capacity are studied using the finite element method. Based on existing experimental research, the established model is verified, and the influence of different influencing factors on the progressive collapse mechanism is analyzed. The results show that the corrosion of the reinforcement affects the yield load, peak load, and ultimate load of the reinforced concrete substructure. As the corrosion rate increases, the tensile arch action shows a particularly severe deterioration. The variation of concrete strength and the height–span ratio affects the substructure’s load-bearing capacity much more significantly than the stirrup spacing.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"6 2 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79798197","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}
The pedestrian evacuation process during the propagation of smoke in case with and without guider is investigated. The effects of leaders on the evacuation are considered. The model is based on the social force model for pedestrians’ motions. The advection–diffusion equation is applied for the dispersion of smoke. The movement direction of a guider is guided by the solution of the Eikonal equation. It relies on the desired speed and the smoke density. A pedestrian who is not a guider follows the rule termed ‘flow with the stream’ and ‘following the wall’. We perform different numerical experiments in a room with one and two exits. The results show that the guiders effect on the evacuation time when they are large number of individuals in simulation. It can help to increase the number of evacuees. With small number of individuals in the experiment, the effect of guiders on evacuation time is not obvious. Further, simulation results are found that the domain with two exits provides higher number of outside pedestrians than the domain with a single door. Longer evacuation time period can increase the number of evacuees. The visibility range of a pedestrian is reduced when an additional smoke source is added to the system. It decreases the number of evacuees. The results of the proposed model are discussed and compared with the existing models.
{"title":"A Pedestrian Evacuation Model with Leaders during the Smoke Dispersion Based on a Social Force Model","authors":"J. Makmul","doi":"10.1155/2023/1029883","DOIUrl":"https://doi.org/10.1155/2023/1029883","url":null,"abstract":"The pedestrian evacuation process during the propagation of smoke in case with and without guider is investigated. The effects of leaders on the evacuation are considered. The model is based on the social force model for pedestrians’ motions. The advection–diffusion equation is applied for the dispersion of smoke. The movement direction of a guider is guided by the solution of the Eikonal equation. It relies on the desired speed and the smoke density. A pedestrian who is not a guider follows the rule termed ‘flow with the stream’ and ‘following the wall’. We perform different numerical experiments in a room with one and two exits. The results show that the guiders effect on the evacuation time when they are large number of individuals in simulation. It can help to increase the number of evacuees. With small number of individuals in the experiment, the effect of guiders on evacuation time is not obvious. Further, simulation results are found that the domain with two exits provides higher number of outside pedestrians than the domain with a single door. Longer evacuation time period can increase the number of evacuees. The visibility range of a pedestrian is reduced when an additional smoke source is added to the system. It decreases the number of evacuees. The results of the proposed model are discussed and compared with the existing models.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"2014 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86666344","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}
The squeezed multiple-branch pile is a variable section pile that was built by adding a bearing branch cavity to a constant section pile using expansion and extrusion equipment. It is widely used in engineering practice for its high bearing capacity, small settlement deformation, high economic benefits, strong adaptability, and simple pile forming process. In this paper, a new type of squeezed multiple-branch pile is proposed and its forming tool is invented. The forming tool of the pile has applied for an invention patent and is authorized by the China National Intellectual Property Administration. Multiple groups of comparison models of the new squeezed multiple-branch piles are established by using FLAC3D numerical simulation software to investigate the influence of the number and spacing of branches on the bearing mechanism in response to uplift load. The results indicated that the number and spacing of branches have a significant effect on the uplift bearing capacity, load–displacement curves, side friction resistance, and stress distribution law in the new pile and soil around the pile. The suitable number and spacing of branches maximize the uplift bearing capacity and minimize the settlement of a single pile.
{"title":"The Effects of Branch Spacing and Number on the Uplift Bearing Capacity of a New Squeezed Multiple-Branch Pile: A Numerical Simulation Analysis","authors":"Qingqing Su, H. Xia, Kunming Wu, Fulian Yang","doi":"10.1155/2023/3758253","DOIUrl":"https://doi.org/10.1155/2023/3758253","url":null,"abstract":"The squeezed multiple-branch pile is a variable section pile that was built by adding a bearing branch cavity to a constant section pile using expansion and extrusion equipment. It is widely used in engineering practice for its high bearing capacity, small settlement deformation, high economic benefits, strong adaptability, and simple pile forming process. In this paper, a new type of squeezed multiple-branch pile is proposed and its forming tool is invented. The forming tool of the pile has applied for an invention patent and is authorized by the China National Intellectual Property Administration. Multiple groups of comparison models of the new squeezed multiple-branch piles are established by using FLAC3D numerical simulation software to investigate the influence of the number and spacing of branches on the bearing mechanism in response to uplift load. The results indicated that the number and spacing of branches have a significant effect on the uplift bearing capacity, load–displacement curves, side friction resistance, and stress distribution law in the new pile and soil around the pile. The suitable number and spacing of branches maximize the uplift bearing capacity and minimize the settlement of a single pile.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"29 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89368003","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}
With the development of the Internet, traditional platforms have been challenged by competition from participants on the platform. However, it is unclear how these two types of population, which are in competition but also mutually dependent, can co-exist in the new platform ecosystem. This paper sheds light on that key phenomenon by extending the population density logistic model of the e-commerce platform ecosystem between participants and platforms based on the symbiosis theory. By solving the logistic equation, we acquire the evolutionary trajectory and final size of populations under different symbiotic patterns. The results reveal that the cooperative and competitive effect determines the equilibrium outcome of the symbiosis evolution of e-commerce platform ecosystem. In the asymmetric symbiosis mode, only one population is influenced by positive synergy that increases population density and promote evolution. The contribution coefficient of subordinate to the dominant is greater than the feedback coefficient from the dominant; the trends of output value are inconsistent. The symmetric symbiosis mode is the optimal model for participants and platforms. The effect “ 1 + 1 > 2 ” can only be achieved under the symmetric symbiosis mode, and the growth of the participants and the platforms is more stable and sufficient than that in other modes. The findings will provide additional perspectives to promote the sustainable development of e-commerce platform ecosystem considering the cooperative and competitive effect.
{"title":"Symbiosis Evolution of E-commerce Platform Ecosystem with Cooperative and Competitive Effect: An Extended Population Density Logistic Model-Based Simulation","authors":"Shan Du","doi":"10.1155/2023/2472618","DOIUrl":"https://doi.org/10.1155/2023/2472618","url":null,"abstract":"With the development of the Internet, traditional platforms have been challenged by competition from participants on the platform. However, it is unclear how these two types of population, which are in competition but also mutually dependent, can co-exist in the new platform ecosystem. This paper sheds light on that key phenomenon by extending the population density logistic model of the e-commerce platform ecosystem between participants and platforms based on the symbiosis theory. By solving the logistic equation, we acquire the evolutionary trajectory and final size of populations under different symbiotic patterns. The results reveal that the cooperative and competitive effect determines the equilibrium outcome of the symbiosis evolution of e-commerce platform ecosystem. In the asymmetric symbiosis mode, only one population is influenced by positive synergy that increases population density and promote evolution. The contribution coefficient of subordinate to the dominant is greater than the feedback coefficient from the dominant; the trends of output value are inconsistent. The symmetric symbiosis mode is the optimal model for participants and platforms. The effect “\u0000 \u0000 1\u0000 +\u0000 1\u0000 >\u0000 2\u0000 \u0000 ” can only be achieved under the symmetric symbiosis mode, and the growth of the participants and the platforms is more stable and sufficient than that in other modes. The findings will provide additional perspectives to promote the sustainable development of e-commerce platform ecosystem considering the cooperative and competitive effect.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"108 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87617692","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}
The flow in the bend channel used as spillway chute is complex due to the turbulence, the presence of shock waves, and vibrations. These transverse waves can damage the hydraulic structure. Our aim in this paper is to investigate the distribution of water surface in five curved channels with five relative curvatures ρ , different bottom slopes (1%, 2%, 10%, and 18%) and three different cross-sections. The objective is to give a solution to reduce the height difference between the inner and the outer walls. To achieve this goal, we used physical models to investigate the flow patterns, explore critical zones, and test several solutions to have a better performance. The reliability and accuracy of the numerical results were validated using the physical modelling for each case tested. Moreover, a comparison between the measured data, theoretical calculations, and numerical outcomes was done, to find a fitting law between the maximum wave height and the bend number. Furthermore, an optimal position of the guide wall was identified in real project of a spillway. The results of the physical model and numerical simulation show a good agreement; thus, the numerical model can play a crucial role in order to study hydraulic parameters, pressure, and velocity field and find solutions for hydraulic problems that occur in these structures.
{"title":"Investigating Supercritical Bended Flow Using Physical Model and CFD","authors":"Hamza Souli, J. Ahattab, A. Agoumi","doi":"10.1155/2023/5542589","DOIUrl":"https://doi.org/10.1155/2023/5542589","url":null,"abstract":"The flow in the bend channel used as spillway chute is complex due to the turbulence, the presence of shock waves, and vibrations. These transverse waves can damage the hydraulic structure. Our aim in this paper is to investigate the distribution of water surface in five curved channels with five relative curvatures \u0000 \u0000 ρ\u0000 \u0000 , different bottom slopes (1%, 2%, 10%, and 18%) and three different cross-sections. The objective is to give a solution to reduce the height difference between the inner and the outer walls. To achieve this goal, we used physical models to investigate the flow patterns, explore critical zones, and test several solutions to have a better performance. The reliability and accuracy of the numerical results were validated using the physical modelling for each case tested. Moreover, a comparison between the measured data, theoretical calculations, and numerical outcomes was done, to find a fitting law between the maximum wave height and the bend number. Furthermore, an optimal position of the guide wall was identified in real project of a spillway. The results of the physical model and numerical simulation show a good agreement; thus, the numerical model can play a crucial role in order to study hydraulic parameters, pressure, and velocity field and find solutions for hydraulic problems that occur in these structures.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"37 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75181840","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}
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