Papers by Keyword: Dynamic Simulation

Abstract: In this work, a method for optimizing the main clamping components for a vibration system on the working body of a plow is presented in order to reduce the forward forces. To achieve this goal, a variable geometric model is established, which considers the unique operational parameters, and a three-dimensional finite element model is generated for conducting an optimization investigation. The 3D finite element analysis is automatically refreshed for each version of the geometric model. An optimization analysis is characterized by its defined goals or objective functions, alongside design variables and constraints. To illustrate, one can adjust the dimensions of a component to minimize material usage, all the while ensuring that stresses remain below a predefined threshold. In this scenario, the volume being minimized serves as the objective function, the dimensions under adjustment represent the design variables, and the stress limitation acts as the behavior constraint. The main objective is to optimize fasteners using finite element analysis to reduce production cost with maximum efficiency.

Abstract: The investigation of silicone rubber properties with the presence of platinum catalyst at different temperature using molecular dynamic simulation was conducted. Visual observation shows that structuring of silicone rubber occurs in the cell where the molecules aggregates closer compared to at the beginning of the simulation and at higher platinum concentration, silicone rubber molecules are more closely packed together. The diffusion coefficient of silicone rubber are the highest in a 10% platinum concentration followed by 25% and lastly 50% indicating that it is harder for the silicone rubber molecules to move from its original position in the system as the platinum concentration increases. Structural changes was also investigated through radial distribution function (RDF) where the position of peaks did not change with time but there is changes observed in the intensity of the peak. At a constant temperature 50°C, it was observed that the intensity of the peak at 1.10Å radius was the highest in the presence of 50%Pt followed by 25%Pt and 10%Pt. This indicates that higher numbers of silicone rubber molecules are present in a 1.10Å radius from the reference molecules in a system with higher concentration of platinum.

Abstract: Dynamic simulation for investigating the interactions of molecules that involved carbon dioxide (CO2), sodium dodecyl sulfate (SDS), water (H2O), hexane and silica nanoparticles (SiO2) in terms of diffusion coefficient and interfacial tension (IFT) were conducted at 298 K and 383 K for three different systems which consists of three layers (L1-L2-L3); CO₂-water-water/hexane (S1), CO₂-water/SDS-water/hexane (S2) and CO₂-water/SDS/SiO₂-water/hexane (S3). Analyses of the mean square displacement (MSD) showed that higher curve definition was obtained at 383 K than 298 K system, indicates higher mobility of the molecules. The diffusion coefficient of all CO₂, SiO₂, SDS and hexane molecules in all systems were higher at 383 K than 298 K due to heat supplied that energized the molecules and enhanced their diffusivity at the elevated temperature. The IFT between L1-L2 (I1) and L2-L3 (I2) determined from the pressure tensor data, decreased from 36.3 to 16.13 mN/m and 42.35 to 6.45 mN/m, respectively for S1 with the increment of temperature. Addition of SDS surfactant further decreased the I1 and I2 from 25.67 to 11.83 mN/m and 29.95 to 9.46 mN/m, respectively for S2 when the temperature increased. The IFT reduced significantly from 25.67 to 0.57 mN/m and 29.95 to 1.13 mN/m for I1 and I2, respectively at 298 K with addition of SiO₂ into SDS-Water i.e. S3. The addition of SiO₂ and SDS further reduced the interfacial tension due to the part taken by SiO2 and SDS in disrupting the closely linked hydrogen bond between water molecules at the interphase.

Abstract: In this paper, chemically modified cellulose was used instead of cellulose as it offers higher adsorption capacities, great chemical strength and good resistance to heat. As part of Phyto-Adsorption Remediation Method, citric acid modified cellulose (CAMC) was used to treat ferric ion. However, there is a large possibility that CAMC molecule might interact with water molecule that contain hydrogen bond and hence pose as a competitor to ferric acid and reduces the efficiency of CAMC in ferric ion removal. Thus, the aim of this work is to identify the most stable hydrogen bond between CAMC and water, by using a computational technique. The interaction between the water molecules and CAMC was observed by varying the volume of water molecule with modified cellulose by an expansion in amorphous region. The simulation result shows that for water loading less than 20 molecules, the interaction between water molecules and CAMC is higher at temperature 311K, whilst for water loading higher than 20 molecules, the interaction weakens at higher temperature. This work proves that water molecules have the tendency to bind to carboxyl group of glucose, to oxygen of ester and to oxygen of anhydride acid of the CAMC molecule, which might pose a competition for ferric acid removal. The calculation of coordination number has shown that the number of atoms present in the first hydration shell (of radius < 2.5Å) is more as the temperature increases from 298K to 311K, which indicates that the adsorption is better at higher temperature. For hydration shell at radius >2.5Å, cell temperature is not significant to the number of atoms present.

Abstract: What Americas Cup and a heritage building have in common They both aim at innovative technologies and cutting-edge solutions. The owner of the project, an ex-crew member of the most famous sailing match race in the world, pushed the planning team to develop extraordinary solutions for his house. The house, Villa Castelli, is an historical listed building located on the Como lake. During its history, it has been transformed many times, giving as results a non-uniform structure composed by different construction technologies. The aims of the owner were: an overall refurbishment particularly focused on energy efficiency, the exploitation of renewable energy sources based on-site production and a fixed budget. To reach these goals, the energy needs have been reduced improving the performance of the thermal envelope. Then, the building's technical systems have been re-developed in order to exploit as much as possible available renewable energy sources. From the very beginning, it was clear that, for finding optimal solutions, a multidisciplinary approach was necessary. The design approach should be the result of a shared approach integrating different fields, such as creative design, technology, knowledge of material properties, building physics. The great synergy among building envelope retrofitting, innovative technological solutions and the deployment of renewable energy sources allows the transformation of this historical listed building into an outstanding example of a nearly zero energy building (nZEB).

Abstract: To reduce the energy and resource consumption in the building sector this study is focusing on a design optimisation of life cycle oriented buildings. In order to optimise the performance of the buildings and in consequence also to achieve improved results for the mandatory Austrian energy certificate a simulation-based rapid design approach is used for the early stage design phase of the buildings, in particular for the architectural design of the buildings.Methods like the Window to Wall Ratio, at the very beginning of the design process, a parametric simulation with EnergyPlus or a more detailed optimisation approach with GenOpt are integrated in this study applied to example buildings. The results are showing that the method can be used in a circular approach for improving the heating demand of the Austrian energy certificate for this case study by more than 25 % compared to the preliminary design

Abstract: Constructing dynamic building models of entire urban districts or cities is a time consuming effort. An automation process is required to shorten the considerable time needed for manual input and to parameterize simulation tools. This paper presents a generation tool for fully automated thermal city modelling that generates dynamic building models with detailed heating systems. The tool is an interface between a PostgreSQL database and the dynamic building energy simulation environment IDA ICE. Tests show that up to 300 automated generated buildings with a simple geometry and 70 buildings each with a heating system can be simulated per CPU.

Abstract: The computer simulation methods of cake growth properties were studied for the slip casting of alumina with gypsum mold. Based on the two-phase flow mixture model, mass conservation of water and maximum close-packed density theory, the numerical calculations were performed for the dynamical cake uniformity, cake density, mold thickness and effective applied pressure in this work. Good agreement was observed between the experimental experience and simulated cake uniformity with the different volume fractions of the slurry and the different sprue gate location conditions. The air-dried cake density and appropriate mold thickness can be estimated quickly by the present formulas. It is useful to simulate the dynamical cake properties with different process conditions which are difficult to detect.

Abstract: In this paper a conjugated heat and moisture transport investigation of industrial floors is presented. We have analyzed 2D general segments of wall and foundation connections in three different climatic conditions: Budapest (Hungary), Lisbon (Portugal) and Espoo (Finland). We also modeled the component with horizontal or vertical edge insulations with various thicknesses and lengths, and two different soil compositions under the floors. The design of the floor and wall components was performed according to the current standards. We examined 126 combination of the segment and the results shows difference both in relative humidity across the components and heat losses through the internal faces. In conclusion, the simulations and results can improve the energy efficient design of industrial buildings across Europe.

Abstract: The paper shows the dynamic simulation in virtual environment of a dual-axis sun tracking mechanism with application in photovoltaic (PV) systems, with the aim to increase the energetic efficiency. The idea is to design a tracking mechanism that automatically changes the diurnal and elevation (altitudinal) position of the PV panel, by considering a predefined tracking algorithm, for maximizing the degree of use of the solar energy (i.e. the incident solar radiation). The tracking mechanism is approached in mechatronic concept, by through the implementation of the two main components (mechanical device, and actuating & control system) at the virtual prototype level. The dynamic simulation was performed by using a virtual prototyping platform, which includes the following software solutions: CATIA, ADAMS/View & ADAMS/Controls, and EASY5. The behavior (performance) of the tracking mechanism is evaluated from energetic efficiency point of view, considering the energy gain reported to an equivalent fixed PV system.