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Konflikt och kärlek i magiska relationer över artgränser i serieboken Mörkrets sång.
Get PDFThis article combines a Human-Animal perspective with a Human-Plant perspective to analyse how the graphic novel Star Stable. Dark Song (2021) by Katie Cook (text) and Elli Pookangas (pictures) depicts a three-part connection between girls, horses and trees. The connection forms a triangular relationship characterized by conflict, strong emotions, and uncompromising ethics. The article argues that the embodied emotional knowledge of the horse-girl – the fictive girls in the novel as well as the girl as a reader of horse books – is crucial for understanding how animals, plants and humans are entangled and co-dependent in the Star Stable-world. The graphic novel uses a fantasy narrative to combine ecological, scientific perspectives on environmental relationships with a mythological and intertextual perspective. The purpose of the article is to answer the question of how complex symbiotic relationships between humans and non-human animals, as well as plants are depicted in Dark Song and how entanglements of narrative traditions and inter-species relationships create intensifications as well as conflicts, confusion and ambiguities.This article combines a Human-Animal perspective with a Human-Plant perspective to analyse how the graphic novel Star Stable. Dark Song (2021) by Katie Cook (text) and Elli Pookangas (pictures) depicts a three-part connection between girls, horses and trees. The connection forms a triangular relationship characterized by conflict, strong emotions, and uncompromising ethics. The article argues that the embodied emotional knowledge of the horse-girl – the fictive girls in the novel as well as the girl as a reader of horse books – is crucial for understanding how animals, plants and humans are entangled and co-dependent in the Star Stable-world. The graphic novel uses a fantasy narrative to combine ecological, scientific perspectives on environmental relationships with a mythological and intertextual perspective. The purpose of the article is to answer the question of how complex symbiotic relationships between humans and non-human animals, as well as plants are depicted in Dark Song and how entanglements of narrative traditions and inter-species relationships create intensifications as well as conflicts, confusion and ambiguities
Thermo-Fluid Modeling Framework for Supercomputer Digital Twins: Part 1, Demonstration at Exascale
Get PDFA thermo-fluid modeling framework is being developed for ExaDigiT—an open-source framework for developing comprehensive digital twins of liquid-cooled supercomputers. The work is being conducted in two parts, and discussion is divided into two companion papers. The work documented in this paper focuses on the development of a cooling system library in Dymola for the Frontier supercomputer at Oak Ridge National Laboratory. The second part, outlined in a companion paper, focuses on a templating structure called Auto-CSM for easily creating modelagnostic, physics-based thermo-fluid cooling system models for liquid-cooled supercomputers using a text-based schema. The cooling model is being developed using primarily the open-source Transient Simulation Framework of Reconfigurable Models (TRANSFORM) library. The library follows the templating architecture developed within the TRANSFORM library for modeling subsystems. A full-system validation was performed to validate a very simple model that is integrated with the system controls, and the results are presented herein
Dynamic simulation models in the planning of experiments for control development
Get PDFThis paper focuses on the utilization of dynamic simulation models in the planning of experiments for control development. The simulation system is a set of models based on the first principles for system level simulation of the complete TCP-100 research facility at Plataforma Solar de Almería (CIEMAT). This new research facility replaced the 32-year-old ACUREX facility with which so many advances in Automatic Control were reached by the research community. The dynamic models are developed to speedup this research for the new field. The part for control development is the solar field whose parabolic trough collectors (PTCs) are modelled in module level and combined into PTCs and loops. The models will be validated with experimental data and the loops are controlled. The sequential loops have different operating conditions. This research uses the parameters based on the parameter selection from providers’ data sheets and the engineering design project of the TCP-100. The system level model has been implemented in the Modelica language. All state variables are temperatures according to the modelling hypothesis applied, solar radiation, ambient temperature, setpoints for both circuits pumps, setpoints for two loops control valves and setpoint for air cooling power. The simulation experiments are first focused on the modules, PTCs and loops of the solar field and the full model need to be extended with dynamic LE models before going to the full simulation tests. In the test campaigns with the new facility, these models will be used for planning the test cases
Numerical simulation of thermal runaway kinetic mechanisms and battery thermal model for safety assessment of different lithium-ion battery chemistries
Get PDFThe importance of EVs and li-ion batteries are pinpointed in the automotive industry during the last decade by increased growth of electrified powertrain. Li-ion batteries offer significant improvements in terms of energy and power density; however, safety challenges continue to exist. Different thermal, mechanical, or electrical abuse conditions in li-ion batteries can trigger a series of exothermic chain reactions in the battery cells and finally result in thermal runaway (TR) and combustion of battery cells and EVs. Furthermore, different battery technologies exploit various cell chemistries, leading to the distinct thermal behavior of battery cells during normal and abuse conditions. This work aims at investigating the TR kinetic mechanisms to evaluate thermal behavior of the battery cells under thermal abuse conditions. Furthermore, this work investigates the different li-ion battery cathode, anode and electrolyte materials to assess the safety of battery systems in EV application. The results revealed that unlike batteries with LiCoO2 cathodes with temperature threshold of 150 ℃, Li1.1(Ni1/3Co1/3Mn1/3)0.9O2 batteries do not undergo TR process at temperatures below 170 ℃. Moreover, the temperature peak is more hazardous in LiCoO2 batteries with LiPF6/PC: DMC electrolyte compared to the same battery with standard electrolyte. In addition, batteries with Lithiated Li4Ti5O12 anode showed safer TR process compared to all the previous battery types
On the Growth Kinetics of Lamellar and Blocky Austenite During Intercritical Annealing of Hot-Rolled Medium Manganese Steel: Thermodynamic and Diffusion-Controlled Transformation Simulations
Get PDFMetastable austenite significantly impacts the mechanical properties of Advanced High-Strength Steels (AHSS), especially Medium Mn Steel (MMnS), where its formation rate during intercritical annealing depends strongly on the initial microstructure. This study employs thermodynamic and diffusion-controlled simulations to investigate the formation of two distinct morphologies of retained austenite–lamellar and blocky known also as globular– commonly observed in an intercritically annealed hot-rolled MMnS. Utilizing Thermo-Calc software, coupled with its DIffusion-Controlled TRAnsformation module (DICTRA), phase equilibria are computed, and one-dimensional diffusion equations are solved. Characterization of the microstructure of a medium manganese steel (MMnS) with a nominal composition of Fe–0.4C–6Mn–2Al–1Si–0.05Nb (in wt. %), hot rolled and intercritically annealed for 1 hour at 680°C, was performed using Energy Dispersive Spectroscopy coupled with Transmission Electron Microscopy (EDS-TEM) and Transmission Kikuchi Diffraction (TKD). These techniques were used for experimental validation and verification of the simulations.Simulations explore the competition between cementite and austenite growth. Specifically, the growth of austenite starting on various interphase boundaries was examined using spherical and planar geometries. This approach resulted in the formation of blocky and lamellar austenite morphologies, respectively. The findings indicate that austenite first nucleates at the BCC/BCC interface and transforms 40% of the BCC phase within 1 second at 680°C. Cementite then starts to form, limiting further austenite transformation. Finally, cementite particles continue to grow to a size of about 100 nm. These simulation results align well with experimental findings
Effect of Slag Particle Diameter on the Re-melting of Ferrochrome Slag by means of Steelmaking Liquid Slag
Get PDFStainless steelmaking slags are, currently, one of the most common non-utilized slags in steelmaking. Hence, in an integrated stainless steelmaking process with a ferrochrome submerged arc furnace, this means not only losing iron to the slag but also valuable chrome. Hence, recovery of iron and chrome have a business incentive and an important function for green industry initiative by reducing the requirement of virgin material.However, one of the challenges of slag recycling can be the energy-intensive nature of such a practice. Therefore, an energy efficient approach in material recovery could enhance the incentive of recycling of slag instead of the current practice of land field storage; one such approach is mixing the solid ferrochrome slag into liquid slag from the steelmaking production line.To that end, a static model of a suspended slag particle inside a melt has been developed to investigate the effect of particle size on evolution of temperature within the solid particles. The simulation showed that changes in the diameter of particle can have a significant effect on energy diffusion from the melt into the slag particle. As an example, the simulation suggests that the temperature magnitude at the centre of a 2mm-in-diameter particle reaches 1200 °C after 1s simulation time while, with 5mm particles the temperature magnitude is less than 200 °C. This behaviour is amplified further when the diameter of particle increases further showing a delaying behaviour of particle’s diameter on energy diffusion and, consequently, remelting of solid particles
Anaerobic digestion of biosolid pyrolysis liquid and hydrolyzed sludge - simulation with extended ADM1 model
Get PDFPyrolysis of biosolids aims to reduce solid volumes and improve energy recovery; however, the pyrolysis liquid (PL) is a by-product that has no good direct application. One idea is to link pyrolysis and anaerobic digestion (AD), in which PL can be valorized for methane production. PL contains various compounds that potentially threaten the stability of AD. This study, therefore, aims to extend the current Anaerobic Digestion Model No.1 (ADM1) and evaluate the influence of phenol, furfural, 5-hydroxymethylfurfural (5-HMF), styrene, and ammonia from PL on AD. Two lab-scale AD reactors were simulated and compared with experimental data: one fed with hydrolyzed sludge and the other fed with an additional stream of PL. The simulation accurately predicts hydrolyzed sludge as substrate, while the simulation of the reactor co-digesting hydrolyzed sludge and PL overestimates methane production. Ammonia, phenol, and styrene were identified as the most significant inhibitors. However, based on the overestimation of methane production, it is clear that the PL has more inhibitors present than those implemented in the model. Simulations further showed that an additional stream of PL increased methane production by 4.3%, even with significant inhibition by the compounds
Impact of grid sensitivity and drag model along with the height of recirculating pipe on a cold flow circulating fluidized bed
Get PDFFluidized bed technology known for its efficient heat and mass transfer and controlled material handling, is widely used across industries. However, CFD simulation of fluidized beds presents challenges that require extensive validation. This study leverages the Multiphase Particle-In-Cell (MP-PIC) method, a recent Lagrangian modeling technique to improve computational efficiency and accuracy. The CAD model was developed using SolidWorks 2020 and simulation was carried out in the commercial CFD package Barracuda VR 21.1.0. The sensitivity of grid size, drag models and the impact of recirculating pipe height after loop seal was examined. Sand particles 63-200 μm and air were used as bed material and fluidization gas respectively achieving full flow circulation at 650 SL/min and 12 SL/min aeration in the riser and loop seal. A total of 19 different simulations were conducted, varying grid size and drag models each for a duration of 45 seconds with a time step of 0.0005 seconds. Pressure transducers along the CFB walls provided validation data. The Wen-Yu Ergun drag model showed a minimal error margin of 0.60%, followed by the Wen-Yu 80000 model at 0.62%, demonstrating high predictive accuracy
Dynamic Reactor Modelling and Operability Analysis of Xylose Dehydration to Furfural Using an Extractive-reaction Process in an Agitated Cell Reactor
Get PDFValorisation hemicellulose into furans chemicals is of great interest to create sustainable furan alternatives to fossil-derived products. A route of particular interest is acid-catalysed dehydration of the hemicellulose pentoses in aqueous medium, with simultaneous extraction of furfural using organic solvent. Agitated Cell Reactor (ACR) could be effectively used to intensify this process and decouple mixing from the long reaction time. This study presents a mathematical model for dehydration of C5 sugars to produce furfural in an ACR. The model can be used to study the effect of feed concentration to the product properties, the concentration profiles along the reactor length, and the dynamic behaviour of the system under feed disturbances or flow rate adjustments. The model was successfully fitted to the experimental data of a laboratory scale ACR for the target product. A simulation study was conducted to analyse the controllability of the process. Operability analysis with the nominal input space and the design space was used for mapping the most feasible region for the process design to meet the flexibility or controllability already at the design phase of the reactor system
Integration of Dynamic Multiphase Flow and Reservoir Models for Improved Oil Recovery Simulation
Get PDFThe utilization of advanced multilateral wells to enhance well-reservoir contact, coupled with water injection, stands out as a common approach to boost oil extraction efficiency. It is imperative to develop precise, fully integrated, dynamic, well-reservoir models tailored for this type of oil recovery to enhance the design of advanced multilateral well completions. This study addresses the challenge by constructing a well model using OLGA®, which is, a dynamic multiphase flow simulator, and a reservoir model using EclipseTM, a reservoir simulator. Subsequently, these models are seamlessly integrated to perform comprehensive simulations. The proposed approach is tested on a case study involving oil recovery through an advanced multilateral well completed with various Flow Control Devices (FCDs) supported by water injection. Results from the simulations demonstrate the success of the integration approach, offering a reliable method for accurately modelling oil recovery from advanced multilateral wells to improve oil recovery. Notably, according to this study, wells completed with Autonomous Inflow Control Valves (AICVs) exhibit superior performance, optimizing oil recovery with a reduced carbon footprint