This work deals with the analysis and design of bioreactors formed by a number of completely stirred tank reactors (CSTRs) in series. The model includes three main components: the concentration of one dominant particulate biomass, one soluble substrate component and one particulate inert matter. The model is analyzed in steadystate conditions. Monod kinetics is used for describing the specific growth rate, and the decay rate of the biomass is included. Two main optimization problems were studied: (i) minimize the effluent substrate concentration for a given total volume, and (ii) minimize the total volume for a given effluent substrate concentration. An alternative to optimize a large number of CSTRs is to consider the asymptotic case of one CSTR followed by a plug-flow reactor (PFR). Numerical results show that there is an optimal volume distribution for the two configurations in each optimization problem.
{"title":"Optimization of Bioreactor Volumes in Steady-State - A Simulation Study","authors":"Hanna Molin, J. Zambrano, B. Carlsson","doi":"10.3384/ECP18153322","DOIUrl":"https://doi.org/10.3384/ECP18153322","url":null,"abstract":"This work deals with the analysis and design of bioreactors formed by a number of completely stirred tank reactors (CSTRs) in series. The model includes three main components: the concentration of one dominant particulate biomass, one soluble substrate component and one particulate inert matter. The model is analyzed in steadystate conditions. Monod kinetics is used for describing the specific growth rate, and the decay rate of the biomass is included. Two main optimization problems were studied: (i) minimize the effluent substrate concentration for a given total volume, and (ii) minimize the total volume for a given effluent substrate concentration. An alternative to optimize a large number of CSTRs is to consider the asymptotic case of one CSTR followed by a plug-flow reactor (PFR). Numerical results show that there is an optimal volume distribution for the two configurations in each optimization problem.","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126060702","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}
Proceedings of The 59th Conference on Simulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway
第59届模拟与建模会议(SIMS 59)， 2018年9月26日至28日，挪威奥斯陆城市大学
{"title":"Distribution of Solids in a Fluidized Bed Operated without a Gas Distributor","authors":"C. Agu, Britt M. E. Moldestad","doi":"10.3384/ECP18153248","DOIUrl":"https://doi.org/10.3384/ECP18153248","url":null,"abstract":"Proceedings of The 59th Conference on Simulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"224 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122612363","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}
D. Rubinetti, D. Weiss, A. Chaudhuri, D. Kraniotis
The present study conceives a numerical model for phase change materials following the apparent heat capacity method where the phase change occurs within a chosen temperature interval. A multiphysical modeling approach to satisfy the coupled momentum, energy and continuity conservation equations whilst avoiding numerical singularities is applied. By means of a 2D test-case geometry with variable boundary heating the influence of natural convection within the melted liquid zone is visualized. Corresponding non-dimensional governing equations are analysed to quantify the dominant contributing terms. It turns out that for sufficiently small Grashof number, or consequently small Rayleigh numbers the influence of natural convection can be neglected, thus simplyfing the problem substantially. The modeling approach has been adapted to a 2D-axisymmetric geometry within the scope of experimental validation. The simulation results and experimental data show reasonably good agreement. The model is numerically stable and suitable to facilitate design of latent heat storage systems.
{"title":"Convective Melting Modeling Approach for Phase Change Materials with Variable Boundary Heating","authors":"D. Rubinetti, D. Weiss, A. Chaudhuri, D. Kraniotis","doi":"10.3384/ECP18153103","DOIUrl":"https://doi.org/10.3384/ECP18153103","url":null,"abstract":"The present study conceives a numerical model for phase change materials following the apparent heat capacity method where the phase change occurs within a chosen temperature interval. A multiphysical modeling approach to satisfy the coupled momentum, energy and continuity conservation equations whilst avoiding numerical singularities is applied. By means of a 2D test-case geometry with variable boundary heating the influence of natural convection within the melted liquid zone is visualized. Corresponding non-dimensional governing equations are analysed to quantify the dominant contributing terms. It turns out that for sufficiently small Grashof number, or consequently small Rayleigh numbers the influence of natural convection can be neglected, thus simplyfing the problem substantially. The modeling approach has been adapted to a 2D-axisymmetric geometry within the scope of experimental validation. The simulation results and experimental data show reasonably good agreement. The model is numerically stable and suitable to facilitate design of latent heat storage systems.","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130323404","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 bending stiffness of subsea cables and umbilicals can be identified from physical tests where the cable is supported at both ends and then pushed or pulled at the center. The beam equation can be used to calculate the bending stiffness from the measured force and the measured deflection. However, a study performed by Nexans Norway AS shows that the beam equation oversimplifies the cables’ properties and thereby disregards significant effects. This paper extends the beam equation into the case of large deflections, which is the second milestone of the work on deriving an accurate model. Within a realistic range of cable deflections, the force calculated by the novel model differs with up to 20% compared to the previous, oversimplified model. From the author’s point of view, this large difference justifies the somewhat increased complexity and computation time of the novel model.
{"title":"Numerical Solution of the Beam Equation for Beams subject to Large Deflections","authors":"Magnus Komperød","doi":"10.3384/ECP18153140","DOIUrl":"https://doi.org/10.3384/ECP18153140","url":null,"abstract":"The bending stiffness of subsea cables and umbilicals can be identified from physical tests where the cable is supported at both ends and then pushed or pulled at the center. The beam equation can be used to calculate the bending stiffness from the measured force and the measured deflection. However, a study performed by Nexans Norway AS shows that the beam equation oversimplifies the cables’ properties and thereby disregards significant effects. This paper extends the beam equation into the case of large deflections, which is the second milestone of the work on deriving an accurate model. Within a realistic range of cable deflections, the force calculated by the novel model differs with up to 20% compared to the previous, oversimplified model. From the author’s point of view, this large difference justifies the somewhat increased complexity and computation time of the novel model.","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124206543","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":"Experimental and Computational study of Chemical Looping Combustion","authors":"R. Thapa, D. Wijeratne, Britt M. E. Moldestad","doi":"10.3384/ecp18153316","DOIUrl":"https://doi.org/10.3384/ecp18153316","url":null,"abstract":"","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114240585","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 study conceives a FVM-based model for ionization processes coupling the incompressible Navier-Stokes equations to Maxwell’s equations adjusted for electrostatics. Modeling instructions for the opensource tool Open-FOAM™ are presented within the scope of defining a customized solver which calculates the distortion of electrical current by an external fluid flow. By means of a simplified test-case the neglegibile impact of external convection on the distribution of space charge for many engineering applications is confirmed while pointing out the limitations of negligible convection. The study shows that peak velocities beyond 100 ms − 1 within the flow field might have an impact on the current distribution, thus requiring careful evaluation of the modeling assumptions. The approach described in the modeling guide proves to be numerically stable. The results for the electric field distribution have been analytically verified.
{"title":"FVM-Modeling of Continuity-Coupled Electrical Charge Submitted to Incompressible Flow with OpenFOAM","authors":"D. Rubinetti, D. Weiss","doi":"10.3384/ecp18153126","DOIUrl":"https://doi.org/10.3384/ecp18153126","url":null,"abstract":"This study conceives a FVM-based model for ionization processes coupling the incompressible Navier-Stokes equations to Maxwell’s equations adjusted for electrostatics. Modeling instructions for the opensource tool Open-FOAM™ are presented within the scope of defining a customized solver which calculates the distortion of electrical current by an external fluid flow. By means of a simplified test-case the neglegibile impact of external convection on the distribution of space charge for many engineering applications is confirmed while pointing out the limitations of negligible convection. The study shows that peak velocities beyond 100 ms − 1 within the flow field might have an impact on the current distribution, thus requiring careful evaluation of the modeling assumptions. The approach described in the modeling guide proves to be numerically stable. The results for the electric field distribution have been analytically verified.","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121781552","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}
Heat pumps have gained a huge popularity as an efficient indoor heating system including several other applications due to relatively low installation cost and energy consumption, and high potential mitigation of global warming than conventional heating systems. The present work aims to develop a modeling tool to investigate dynamic behavior of heat pumps for heating applications. A vapor-compression, air-source HP house heating system with a zeotropic refrigerant R-407c is developed using MATLAB R (cid:13) based Simscape TM language. The system components such as the evaporator, compressor, condenser, expansion valve, house and the controller are modeled using a combination of Simscape TM foundation libraries. Each component model has a set of tunable parameters that can be adjusted by user preferences in order to simulate the real-time operation. The dynamics of the system and its response to variable ambient temperature is investigated and discussed. The model depicts the expected behaviour under the simulated operating conditions and is capable of maintaining a comfortable user defined heating temperature inside the house. The model developed will be used to gain insight into performance characteristics of heat pump systems used for local production in the district heating.
热泵作为一种高效的室内供暖系统已经获得了巨大的普及，包括一些其他应用，由于相对较低的安装成本和能源消耗，以及比传统供暖系统高的减缓全球变暖的潜力。目前的工作旨在开发一种建模工具来研究热泵在加热应用中的动态行为。基于Simscape TM语言，利用MATLAB R (cid:13)开发了一种采用R-407c共变制冷剂的蒸汽压缩空气源高压室内供暖系统。结合Simscape TM基础库对蒸发器、压缩机、冷凝器、膨胀阀、机房和控制器等系统部件进行建模。每个组件模型都有一组可调参数，这些参数可以根据用户偏好进行调整，以模拟实时操作。研究和讨论了系统的动力学特性及其对环境温度变化的响应。该模型描述了在模拟操作条件下的预期行为，并能够保持用户定义的舒适的室内加热温度。所开发的模型将用于深入了解用于区域供热的本地生产的热泵系统的性能特征。
{"title":"Dynamic model of a heat pump based house heating system","authors":"Shobhana Singh, K. Sørensen","doi":"10.3384/ECP1815387","DOIUrl":"https://doi.org/10.3384/ECP1815387","url":null,"abstract":"Heat pumps have gained a huge popularity as an efficient indoor heating system including several other applications due to relatively low installation cost and energy consumption, and high potential mitigation of global warming than conventional heating systems. The present work aims to develop a modeling tool to investigate dynamic behavior of heat pumps for heating applications. A vapor-compression, air-source HP house heating system with a zeotropic refrigerant R-407c is developed using MATLAB R (cid:13) based Simscape TM language. The system components such as the evaporator, compressor, condenser, expansion valve, house and the controller are modeled using a combination of Simscape TM foundation libraries. Each component model has a set of tunable parameters that can be adjusted by user preferences in order to simulate the real-time operation. The dynamics of the system and its response to variable ambient temperature is investigated and discussed. The model depicts the expected behaviour under the simulated operating conditions and is capable of maintaining a comfortable user defined heating temperature inside the house. The model developed will be used to gain insight into performance characteristics of heat pump systems used for local production in the district heating.","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132634979","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}
Pipes are essential components in engines and therefore models of them are important. For example, the aftertreatment system for modern heavy-duty diesel engines consists of multiple components that are connected using pipes. The temperature in each of these components are important when determining the efficiency of the aftertreatment system and therefore models that accurately describe the temperature in the pipes between the components are important. Here, a dynamic pipe model that combines the adiabatic model of a control volume and that of a stationary one-dimensional flow with heat transfer in a pipe is developed and validated. The resulting model is a quasi-dimensional lumped parameter mean value model containing states for the temperature and pressure of the gas inside the pipe and the temperature of the pipe wall. The model uses the states and convective heat transfer models to calculate pressure at the inlet and outlet as well as temperature at the outlet, in a way that is physically correct under certain conditions. To validate the physical behavior of the model a detailed one-dimensional model is used, and to validate the practical applicability and accuracy of the model data from a passenger car gasoline engine is used to parameterize and validate the model.
{"title":"A Mean Value Model for Unsteady Gas Flows and Heat Transfer in Pipes","authors":"Olov Holmer, L. Eriksson","doi":"10.3384/ECP18153284","DOIUrl":"https://doi.org/10.3384/ECP18153284","url":null,"abstract":"Pipes are essential components in engines and therefore models of them are important. For example, the aftertreatment system for modern heavy-duty diesel engines consists of multiple components that are connected using pipes. The temperature in each of these components are important when determining the efficiency of the aftertreatment system and therefore models that accurately describe the temperature in the pipes between the components are important. Here, a dynamic pipe model that combines the adiabatic model of a control volume and that of a stationary one-dimensional flow with heat transfer in a pipe is developed and validated. The resulting model is a quasi-dimensional lumped parameter mean value model containing states for the temperature and pressure of the gas inside the pipe and the temperature of the pipe wall. The model uses the states and convective heat transfer models to calculate pressure at the inlet and outlet as well as temperature at the outlet, in a way that is physically correct under certain conditions. To validate the physical behavior of the model a detailed one-dimensional model is used, and to validate the practical applicability and accuracy of the model data from a passenger car gasoline engine is used to parameterize and validate the model.","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130676441","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}
L. I. Hatledal, Houxiang Zhang, A. Styve, G. Hovland
{"title":"FMI4j: A Software Package for working with Functional Mock-up Units on the Java Virtual Machine","authors":"L. I. Hatledal, Houxiang Zhang, A. Styve, G. Hovland","doi":"10.3384/ECP1815337","DOIUrl":"https://doi.org/10.3384/ECP1815337","url":null,"abstract":"","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115657571","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}
Feedback is one of the key factors that makes industrial simulator training an effective learning tool. Usually, the trainees receive feedback from the instructor, who guides them through the simulation tasks. However, nowadays the availability of expert instructors is scarce while the training demand is increasing. Therefore, there is a need for new simulator training practices that could allow the trainees to be more independent and decrease the need to rely so often on the instructor. This could be achieved by offering the trainees online automated feedback. This article presents a method for developing a tool meeting those requirements is presented. Simulation data were gathered representing different execution paths of the same scenario. Data were then analyzed and clustered using different clustering techniques. Interestingly, “good” and “bad” performances are shown to be separable using different techniques for clustering multivariate time series. Furthermore, we introduce the concept of enclosing data tunnel representing the trajectory of well-behaving execution paths in a reduced dimensional space. By conditioning the mal-behaving performances to be less than 20 % of the total simulation time inside the tunnel, an accuracy on 68 % was obtained. Being more flexible and allowing the mal-behaving performances to be inside the tunnel for a maximum of 35 % of the total simulation time, the accuracy of the enclosing tunnel was increased to 84 %.
{"title":"Using the concept of data enclosing tunnel as an online feedback tool for simulator training","authors":"L. Marcano, A. Yazidi, D. Manca, Tiina Komulainen","doi":"10.3384/ECP18153132","DOIUrl":"https://doi.org/10.3384/ECP18153132","url":null,"abstract":"Feedback is one of the key factors that makes industrial simulator training an effective learning tool. Usually, the trainees receive feedback from the instructor, who guides them through the simulation tasks. However, nowadays the availability of expert instructors is scarce while the training demand is increasing. Therefore, there is a need for new simulator training practices that could allow the trainees to be more independent and decrease the need to rely so often on the instructor. This could be achieved by offering the trainees online automated feedback. This article presents a method for developing a tool meeting those requirements is presented. Simulation data were gathered representing different execution paths of the same scenario. Data were then analyzed and clustered using different clustering techniques. Interestingly, “good” and “bad” performances are shown to be separable using different techniques for clustering multivariate time series. Furthermore, we introduce the concept of enclosing data tunnel representing the trajectory of well-behaving execution paths in a reduced dimensional space. By conditioning the mal-behaving performances to be less than 20 % of the total simulation time inside the tunnel, an accuracy on 68 % was obtained. Being more flexible and allowing the mal-behaving performances to be inside the tunnel for a maximum of 35 % of the total simulation time, the accuracy of the enclosing tunnel was increased to 84 %.","PeriodicalId":350464,"journal":{"name":"Proceedings of The 59th Conference on imulation and Modelling (SIMS 59), 26-28 September 2018, Oslo Metropolitan University, Norway","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115536392","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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