Master's thesis "VRF system" aims on the energy simulation of energy needs for HVAC system of one floor of the FSI NetMe Research Centre building and followed evaluation of the advantage of using VRF system with heat recovery function. The first part is a theoretical introduction, which describes the basics of the mechanical refrigeration, following the differences and ways of functioning of the VRF system with heat recovery function. Practical part of this work is aimed on the description of the way of data input into the simulation tool. Finally, the results of the simulation and economical comparation of the VRF system and the existing four-pipe cold and warm water distribution system are presented

This Master’s Thesis focuses on development and realization of analog system software simulator for simulation of various kinds and orders systems and for function verification of microcontrollers’ control systems. The development and realization of PSD controller is part of this thesis as well. The simulator is written in C++/CLI programming language which combines fast execution of native code and provides an advantage of managed code which has its execution managed by the .NET Framework. The data acquisition is performed via National Instrument’s USB multifunctional DAQ. The PSD regulator is realized by using modern ARM processor architecture.

Practicing engineers need an integrated building, HVAC and control simulation tool for optimum HVAC design and retrofit. Various tools are available to the researchers, but these are not appropriate for the consulting engineer. To provide the engineer with a tool which can be used for typical HVAC projects, new models for building, HVAC and control simulation are introduced and integrated in a user-friendly, quick-to-use tool. The new thermal model for buildings is based on a transfer matrix description of the heat transfer through the building shell. It makes provision for the various heat flow paths that make up the overall heat flow through the building structure. The model has been extensively verified with one hundred and three case studies. These case studies were conducted on a variety of buildings, ranging from a 4m2 bathroom, to a 7755 m2 factory building. Eight of the case studies were conducted independently in the Negev Desert in Israel. The thermal model is also used in a program that was custom-made for the AGREMENT Board (certification board for the thermal performance of new low-cost housing projects). Extensions to the standard tool were introduced to predict the potential for condensation on the various surfaces. Standard user patterns were incorporated in the program so that all the buildings are evaluated on the same basis. In the second part of this study the implementation of integrated simulation is discussed. A solution algorithm, based on the Tarjan depth first-search algorithm, was implemented. This ensures that the minimum number of variables are identified. A quasi-Newton solution algorithm is used to solve the resultant simultaneous equations. Various extensions to the HVAC and control models and simulation originally suggested by Rousseau [1] were implemented. Firstly, the steady-state models were extended by using a simplified time-constant approach to emulate the dynamic response of the equipment. Secondly, a C02 model for the building zone was implemented. Thirdly, the partload performance of particular equipment was implemented. Further extensions to the simulation tool were implemented so that energy management strategies could be simulated. A detailed discussion of the implications of the energy management systems was given and the benefits of using these strategies were clearly illustrated, in this study. Finally, the simulation tool was verified by three case studies. The buildings used for the verification ranged from a five-storeyed office and laboratory building, to a domestic dwelling. The energy consumption and the dynamics of the HVAC systems could be predicted sufficiently accurately to warrant the use of the tool for future building retrofit studies / Thesis (PhD)--University of Pretoria, 1997. / gm2014 / Mechanical and Aeronautical Engineering / unrestricted

Il y a des nombreuses méthodes capables de produire des modèles numériques très précis des systèmes électromagnétiques. Si la précision demandée est très importante ou la nature du phénomène modélisé est très complexe, il faudra résoudre un nombre élevé d’équations. Si le modèle est utilisé dans des applications où de nombreux paramètres doit être prises en compte, comme c’est le cas de la conception optimale, la résolution de ces équations est souvent très couteuse.Pour éviter ce calcul, des algorithmes de réduction de modèle ont été développés. Il s’agit de procédures permettant de trouver des modèles réduits qui représentent la relation entrée/sortie du modèle fin de manière très précise mais en utilisant un nombre réduit d’équations.Dans cette thèse, les techniques de réduction de modèles sont analysées et améliorées. Une attention particulière est faite à la technique de correspondance des moments. Les problèmes de placement des points d’expansion, de stabilité et de précision sont plus particulièrement étudiés. Cela a permit la simulation et conception optimale de modèles électromagnétiques complexes qu’un jeu de bus bar et un problème de diffusion d’ondes.De plus, nous avons développé une méthode d'échantillonnage adaptatif. Des algorithmes classiques d’optimisation ont été couplés aux modèles réduits permettant l’accélération des calculs. Les méthodes proposées ont été testés dans des problèmes électromagnétiques obtenus par la méthode « Partial Equivalent Circuit Element (PEEC) ». / There are many available methods capable of producing High-Fidelity Models (HFM) of electromagnetic systems. If the required precision is very high or the nature of the phenomenon that is being modeled is complex, a very large number of equations may have to be solved. If the model is used for applications where many different geometries or parameters must be considered, as is the case in design optimization, solving these equations many times can be very time consuming.To avoid the burden of this computation, Model Order Reduction (MOR) algorithms have been developed. They consist in procedures of finding Reduced Order Models (ROMs) that accurately describe the input/output behavior of the High-Fidelity Model but using only a very small number of equations.In this work, MORs techniques are analyzed and improved. Special attention is paid to Moment Matching. Problems like placement of expansion points, stability and numerical robustness are investigated. This has allowed the simulation and optimization of complex electromagnetic device. As examples of application we have presented a laminates bus bar and a wave scattering problem.In addition to that, a smart adaptive way of sampling the design space to allow fast optimization has been developed. The sampled points are used to perform interpolation and approximate the objective function in a very fast manner. Classic optimization techniques have also been coupled with the Reduced Order Models, accelerating the computations. The proposed approaches have been tested mainly in electromagnetic problems obtained by the Partial Equivalent Circuit Element (PEEC) method.

Despite the rapid growth of compute power in the last decades, the full-fledged, 3D mathematical models of fuel cells are not a viable option when it comes to applications requiring real-time capability; on the other hand, the current crop of 1D models apply boundary conditions pertinent merely to a single point in the cell – to provide data for effective fuel cell system design, a balance needs to be struck. The predictive power of a lower dimensionality fuel cell model can provide a reasonably detailed and accurate assessment and tracking of the fuel cell state and cater data to model-based control algorithms or define requirements for the selection of balance of plant components. To cover a wide parametric space and allow a rapid generation of the corresponding fuel cell system states, a combination of two 1D stationary models (a pseudo-2D model) has been chosen. One model defines the inlet conditions and tracks their evolution along a gas flow channel in a bipolar plate, while the second model (in our case the MMM1D published by Vetter and Schumacher) solves the evolving boundary-value problem throughout the membrane-electrode assembly (MEA) and calculates the fluxes of species, heat and charge exchanged between the gas flow channel and the MEA. Because the most significant changes in the media state (temperature, pressure, composition and flow rate) occur at the cell level, the model can estimate stack outlet conditions from the inlet conditions, extending the cell level model to a fuel cell system context. The results obtained for several operating points are used to discuss the choice of some system components.

No description available.

Computer simulation software’s are arguably some of the most convenient and utilized tools for an engineer as it lets them model real phenomena and observe different operations without having to perform the operation physically, thus saving both time and resources. Naturally these tools varies in design depending on their intended area of application and while a large number of them supports modeling of more than one physical domain, it is often cumbersome to attain a functional interaction between them. In spite of this there do exist simulation software that have been specifically developed for effectively integrating several physical domains known as system simulation software’s. One of these are Siemens Simcenter Amesim, a computer simulation software for modeling multi domain mechatronic systems. One company that has recently found an interest in potentially adapting the concept of system simulations into their workflow is BAE Systems Hägglunds, Örnsköldsvik, where a pre-study has previously been conducted in order to define a system requirement specification as well as narrow down the number of promising tools to only a few, with Simcenter Amesim being one of them. The aim of this study is then to evaluate and assess to what degree Simcenter Amesim complies with the requirements specified by the company. The primary source of information in which this analysis will be based upon is through the modeling of two different pilot cases in Simcenter Amesim, an electric driveline as well as the hydraulic component of the active suspension system affiliated with the CV90 vehicle. The electric driveline was developed as a general model featuring a few key functionalities in terms of power setup. This being that two electric motors were to be utilized, one for driving the vehicle forward and the other for steering the vehicle left and right. Powering these two was then an electric generator which by itself was to be powered by an internal combustion engine (ICE). The active suspension system was modeled based on existing schematics and information available through company resources with the ambition of realizing a certain behavior of the system as described by a couple of real tests made. Results from simulations made using the electric driveline model indicates that the model succeeds in fulfilling its fundamental functionality. Through plain throttle and steering inputs the corresponding vehicle is able to move about in a simple and predictable fashion with data also showcasing realistic behavior in terms of velocity evolution and power generation. The hydraulic model of the CV90 active suspension system furthermore appears to replicate the behavior of the actual suspension system fairly well based on the real test data available. Analogous with both models however is the fact that they are rather primitive in their current state. The electric driveline model lacks some of the finesses and functionalities that are included in modern driveline systems, mostly coupled to the component steering and feedback system which is more arbitrarily implemented in this model. As for the hydraulic suspension system it would be beneficial to continue develop the model through further evaluation using more real life test data.

International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / TASC is currently developing for the GPS Range Applications Joint Program Office (RAJPO) the mission planner which will be used by test ranges procuring RAJPOdeveloped GPS test range instrumentation. Test Range User Mission Planner (TRUMP) is a user-friendly, PC-resident tool which aids in deploying and utilizing GPS-based test range assets. In addition to providing satellite/jammer visibility (for a Digital Terrain Elevation Data (DTED) range map) and dilution-of-precision (DOP) information, TRUMP features: C Time history plots of time-space-position information (TSPI) C Performance based on a dynamic GPS/inertial system simulation C Time history plots of TSPI data link connectivity C DTED maps with user-defined cultural features C Two-dimensional coverage plots of ground-based test range assets. This paper will discuss TRUMP’s role on the test ranges and its current features. In addition, the functionality to be added during the next development phase will be presented.

一、研究目的： 華江橋台北端為一圓環，在交通尖峰時間，此一圓環容易發生壅塞，車輛通過頗為費時。由於華江橋圓環目前所有進出路口均為雙向行車，車輛進出皆無任何管制，假若吾人對進出華江橋圓環的車輛施予若干管制，其交通是否會獲得改善？針對這個問題，本研究之目的即為：(1)制訂華江橋圓環的交通管制策略。(2)建立華江橋圓環交通的模擬模式，以便進行各種交通管制策略之評估。 二、研究方法： 本研究制訂交通管制策略的方法是根據有關文獻的結論與建議，參酌實際上華江橋圓環的交通狀況而主觀訂定各種改善策略。由於每個圓環的幾何形狀與交通流量的情形不會完全相同，因此吾人必須將所訂定的策略加以評估。本研究所用的評估方法是固定時間增加的模擬分析法(Fixed-time Incremental Simulation Analysis) 三、研究內容： 本文共分六章。第一章介紹研究動機、目的、資料來源及研究方法。第二章為有關文獻之探討。第三章介紹系統模擬的基本概念及進行的步驟。第四章說明如何調查華江橋圓環的交通流量，並對調查結果作了必要的統計檢定。第五章建立了華江橋圓環模擬模式，並對所建立的模擬模式作了信度檢定。第六章為各種管制策略的模擬結果與分析，並選定一組較佳之華江橋圓環交通管制策略。 四、研究結果： 本研究之結果顯示，在尖峰時間內若禁止車輛從環河南街往西門町的路口離去，同時以各路口車輛到達數來控制車輛進入圓環，可以獲致良好的交通管制效果。

Performance-based landfill design approach is a relatively new design approach adopted recently in solid waste management and applied in USA, European Union countries and some developing-economy countries like South Africa. This approach rejects the strict design criteria and accommodates a design that selects the most appropriate design components of a landfill (final cover, bottom liner, and leachate collection system) and their design details to result in the best overall performance with respect to performance criteria (groundwater contamination and stability) considering the system variables (climatic conditions of the site, site hydrogeology, and size of the landfill). These design components, performance criteria and design variables involved in decision process make performance-based landfill design a complex environmental problem. Decision support systems (DSS) are among the most promising approaches to confront this complexity. The fact that different tools can be integrated under different architectures confers DSSs ability to confront complex problems, and capability to support decision-making processes. In this thesis study, a DSS to aid in the selection of design components considering the design variables and performance criteria for performance-based landfill design was developed. System simulation models and calculation modules were integrated under a unique DSS architecture. A decision support framework composed of preliminary design and detailed design phases were developed. The decision of appropriate design components leading to desired performance was made based on stability issues and vulnerability of groundwater, using knowledge gathered from DSS. Capabilities and use of the developed DSS were demonstrated by one real and one hypothetical landfill case studies.