Papers by Keyword: Simulation Model

Abstract: While light shelves enhance daylight inside buildings in tropical climates, there is a concern that the heat reflected from them will increase the cooling load inside a building. In this study, experiments are conducted under controlled conditions to understand the heat transmission characteristics of light shelves. The total heat reflected by a prototype of a light shelf is compared to the case of a similar setup with a no light shelf. Different materials were tested to evaluate the heat and light transmission. A mirror glass light shelf gave the highest illuminance, whereas an aluminium light shelf transmitted maximum heat. To explain the experimental results, a simulation model was created using the heat balance equation for the light shelf. The Mean square error between the simulation and experimental data is computed to predict the heat transmitted by the light shelf. The simulation model could reasonably replicate the trends obtained in the experimental data. The simulation model helps in controlling the heat transferred by light shelves in tropical climates.

Abstract: The results of a survey of the background parasitic characteristics on individual structures of the municipal sewage treatment plant are given. It is established that 27% of the grids and sand trap are retained, the effectiveness of the retention in the biological treatment facilities after the secondary settling tank corresponded to 61.9%. Helminth eggs are mostly concentrated in sewage sludge, to a large extent maintaining their viability (90%). An imitating model of the process of disinvasion of sewage and sediments was developed, represented by a network diagram for sewage treatment fa-cilities. In production conditions, an experiment was performed to determine the influence of exter-nal factors on the efficiency of dehelmintization by the plant reagent.

Abstract: This paper presents a petri net model for examining effectiveness of straddle carrier direct-system operation. Dynamic of operation is addressed by formal petri net model that affiliates types of operation and sequences of motion for various agents in container terminal. An interchange model in the petri net is introduced to represent transloading process that controls the flow of containers between agents. In addition, simulation model was developed to examine the deployment scenarios of gantry cranes, straddle carriers and truck slots at transfer point. The results suggest terminal performance indicators such as level of productivity, waiting time and equipment’s idle time for each deployment scenarios which is beneficial as decision support systems for efficient management of terminal equipment.

Abstract: The objective in this study was to conduct a technical-economic study of the esterification process of used vegetable oils (UVOs) for the production of biodiesel from the point of view of energy savings achieved by implementing heat exchange networks (HENs). Used vegetable oils (UVOs) can be employed as an input in the production of biodiesel by catalytic transesterification. But, previously it is necessary to reduce its level of free fat acids (FFA) by the acid-catalyzed esterification process in order to prevent undesirable saponification reaction. To carrying out an optimal design of the technology required in the process, simulation tools have an important role for process engineering and optimization of resources. Computer programs such as Aspen PlusTM and Aspen Energy AnalyzerTM provide an environment to perform process modeling and network design optimal heat exchange. In this paper, from the Aspen PlusTM simulation of the process of catalytic esterification in acid medium of UVOs, the technical-economic evaluation process was conducted with and without network of heat exchange in order to analyze the different investment options. The comparison of the two projects (with and without the implementation of HENs) was performed by determining the net present value (NPV). On the scale set for the project, the total cost of the equipment of heat exchange for the esterification process designed with HENs was US$ 4,782.50 higher than the corresponding to the process without HENs application. However, it should be noted that the cost of services decreased by 30% annually, and on the other hand, comparing the process, it was observed that the NPV of the HENs process was 29.5% higher, which leads to the conclusion that the project which includes heat exchange networks is technically and economically feasible.

Abstract: In order to efficiently supercharge Diesel engines with pressure wave superchargers it is necessary to correlate the superchargers rotation speed with certain parameters of the supercharged engine. For this purpose, to reduce the research costs and duration, simulation models can be used which help to determine the parameters which have a major impact on the supercharger's rotational speed and efficiency. In this paper there are presented two simulation models: a one-dimensional (made in AMESim software) and a three dimensional (made in Fluent Software). This simulation models offer the possibility to visualize some dynamic phenomenon within the supercharger, like the evolution of the pressure waves or the turbulent flow inside the rotor channels. These phenomena are difficult and expensive to study with conventional methods.

Abstract: The continuously tightening regulations limiting the amount of exhaust gas components of internal combustion engines force the manufacturers to further increase the effectivity of their power units. Due to the already relatively highly-developed state of engines result in the need of research and development of even smaller engine parts – e.g. piston rings. The main aim of this project was to develop a tool for the computer simulation of the behavior of the piston ring pack, which could aid the optimization process of the piston ring pack towards lowered friction losses.

Abstract: Experimental studies of production technological processes are now enabled through a use of the available simulation software. The scientific studies, executing experiments with simulation software, are used to optimize, improve efficiency, and elimination of deficiencies in manufacturing processes without any interfering with the real processes. The big advantage is that by using simulation software, one can simulate a number of experimental variations of scenarios in advance, and evaluate any intervention in the course of the active process. Experiments with a built simulation model answer the questions of what-if analysis for variable set scenarios.

Abstract: Simulation as a decision making method through its software is a supportive tool for analysis of a material flow, and it is appropriate when a performance of complex systems have to be evaluated, designed and optimized. As the behavior of complex systems is hardly predictable, simulating the existing systems’ performance is helpful in order to gain results of system performance before applying changes in a real system. A change that appears to be a best solution might, after calculation and analysis of its consequences, prove as a wrong direction lead. The more accurately is the model built, the more real results are being achieved. Decisions about the performance improvement might be intuitive as what-if analysis, or achieved by process redesign and improvement methods as Theory of Constraints, Lean Manufacturing, Six Sigma Method, some of them with slight changes in a single processes following Kaizen principles.

Abstract: The aim of the paper is to propose the concept of mechatronic system, which will have a good ability to overcome obstacles encountered in urban and non-urban environments. With its properties and characteristic features it should be able to adapt to diverse terrain, overcome obstacles such as stairs, slopes, rocks, but also muddy, sandy or slippery surface. The requirements and criteria imposed on this robot will depend on the mentioned properties.

Abstract: The automatic heating control systems seem to be the nonlinear systems with thermal inertias and time delay. The controller is also nonlinear because its information and power signals are limited. Application of methods, which are available for nonlinear systems together with computer simulation and mathematical modeling, create possibility to reach serious information about researched system. The paper contains the heating system model with the cascade control, simulation model of this system and some simulation results created in Matlab/Simulink environment.