Simulation tool reliability

For proper use of the simulation tools and to get reliable results, the following procedure is suggested ... 

Despite the recent rapid development of computer technology and numerical methods, the rate-based approach in its current realization still often requires a significant computational effort, with related numerical difficulties. This is one of the reasons the application of rate-based models to industrial tasks is rather limited. Therefore, further work is required in order to bridge this gap and provide chemical engineers with reliable, consistent, robust, and comfortable simulation tools for reactive separation processes. 

Despite highly developed computer technologies and numerical methods, the application of new-generation rate-based models requires a high computational effort, which is often related to numerical difficulties. This is a reason for the relatively limited application of modeling methods described above to industrial problems. Therefore, a further study in this field - as well as in the area of model parameter estimation - is required in order to bridge a gap and to provide process engineers with reliable, consistent, robust and user-friendly simulation tools for reactive absorption operations. 

Yates in, W.D. Beaman, D.M. 1995. Design Simulation Tool to Improve Product Reliability, Proceedings of Annual Reliability and Maintainability Symposium 193-199. 

Catuneanu, VM., Popenpiu, R 1989. Optimization of the system s reliability. Bucharest Editor of Academy Pang H., Chen L., Dlakavu N Shen Z., Basic Modeling and simulation Tool for Analysis of Hydraulic Transients in Hydroelectric Power Plants, IEEE Transactions, on Energy Conversion, vol. 23, no. 3, pp. 834-842, September 2008... 

It is important to learn as much as possible from accidents because they are often the only way of obtaining data that can be used to develop more reliable models for predicting the effects of explosions. This is especially true for effects for which simulation tests cannot be performed with reasonable cost and for which computer simulation tools either do not exist or are not reliable. Whenever possible, technical experts should insist on an extensive documentation of the real hard facts in any case where debris is produced by an explosion accident. 

These tools can be used for several applications plaiming, optimization, diagnosis, and control. Their integration in overall system simulation allows reliable plant design and the setting up of the operating conditions while checking the local constraints, for example, the maximum temperature on the cell plane or the maximum difference between the anode and cathode pressures. 

ICG TC21 MODELING OF GLASS MELTING PROCESSES - HOW RELIABLE AND VALIDATED SIMULATION TOOLS CAN HELP TO IMPROVE GLASS MELTING EFFICIENCY AND PRODUCTIVITY. 

In many scenarios, the analysis of the anomaly system is treated as an or indivisible. Substantive feature of the system as a whole is that its properties are not trivial functions of the properties of its components. In contrast instantiation is carried out taking into account the relationships between the elements. Become critical in the process of reliability of the item and the need for taking into account external factors (environmental impact). The process of reliability system modeling is a fundamental operation requiring the designer knowledge and technical skills. Supports are mathematical models, system engineering and simulation tools. The final step is to perform simulation studies and locals. For the issue in the article problems OTE collections are man (operator behaviour), machine (device structures and mechanisms for proper operation) and exposure (resistance to destruction). 

ABSTRACT Goodtech and Statnett SF have developed an online regularity calculator with minimal delay between acquisition of process values and presentation of regularity indices for the power grid. The simulation tool cdculates the probability of failure on every component in the system and combined with a flow model, the reliability of power supply for every load branch. In order to analyze and understand all risk and reliability changes every 10 minutes for the large network a new representation method must be developed and tested. 

The Promaps simulation tool calculates the power delivery reliability as a function of demand, the probability for undelivered energy for each load branch in the system and for the system as a whole. Therefore the CENS cost factor could easily be included in the results and are currently one of the system risk indicators used. In addition not delivered energy and corresponding CENS cost. System Minutes (SMS) is used as an onhne risk indicator. 

After installing the new simulation tool for reliability studies at Statnett SE, the need for a customized presentation method has become prominent. 

ABSTRACT Availability and reliability evaluation of redundant systems under periodic maintenance is one of the difficulties in the field of reliability engineering. In order to overcome the disadvantages of existing evaluation methods, an instantaneous availability analytic approach for such systems is deduced, considering fault detection rate, fault isolation rate and repair rate. Limitations of this approach are discussed. Furthermore, a simulation model is devised to accomplish the evaluation of instantaneous availability and MTBCF. The validity of this simulation method is proved. And a simulation tool for availability and reliability evaluation of redundant systems periodically maintained is developed with MATLAB. At last, a case is studied. 

Applying the availability and reliability simulation approach for redundant systems periodically maintained, a simulation tool is developed, the interface of which is depicted in Figure 4. Set 1000 times of simulation, the instantaneous availability distribution of the source array is obtained, as shown in Figure 5, and the MTBCF equals to... 

An analytic and a simulation approaches are presented in this paper. Both of the approaches are aimed at solving the problem of availabiUty and reliability evaluation of redundant systems under periodic maintenance, considering fault detection rate, fault isolation rate and repair rate. Using the simulation tool we have developed, instantaneous availability and MTBCF of the system could be easily obtained, which are of great significance for designers to make and optimize the maintenance policy. The simulation efficiency would be raised in further application to shorten the simulation time. 

At this time, there are a number of numerical simulation tools that are widely used throughout the world to analyze a transient in a power system. Among them, the most well-known and widely used tool is EMTP. The accuracy and reliability of the original EMTP has been confirmed by a number of test cases since 1968. However, there is no perfect simulation tool in this world. Any simulation tool has its own application limits and restrictions. As previously discussed, the EMTP, based as it is on a circuit theory under the assumption of TEM mode propagation, cannot give an accurate solution of a transient associated with non-TEM mode propagation. Such application limits and restrictions are discussed in Chapter 8 for both circuit-theory-based approaches and NEA methods. 

Quite often, a problem appears unexpectedly for a user but not for the developers of a simulation tool it is hard for developers to predict such problems at the development stage. These problems are caused quite often by the misuse of the tool by the user. Therefore, reliability and severity tests of simulation tools are very important. For example, it took nearly 10 years to carry out reliability and severity tests on tens of thousands of cases with EMTP cable constants. It should be noted that the reliability of a tool (that is, the probability of a problem occurring) is proportional to the number of elements (that is, the number of subroutines and options) although each individual element has very high reliability. Input data often cause numerical instability when the data physically do not exist this problem is related to the assumption of formulas adopted in the simulation tool as explained in Section 8.1. To avoid such a problem, a KILL CODE is prepared in the EMTP. The kill code judges whether the input data are beyond the limits of assumption. It may be noteworthy that nearly half of the EMTP codes are kill codes. This may be considered by developers in another simulation tool. 

Having previously introduced the key methods to determine the important variables with respect to stress and strength distributions, the most acceptable way to predict mechanical component reliability is by applying SSI theory (Dhillon, 1980). SSI analysis is one of the oldest methods to assess structural reliability, and is the most commonly used method because of its simplicity, ease and economy (Murty and Naikan, 1997 Sundararajan and Witt, 1995). It is a practical engineering tool used for quantitatively predicting the reliability of mechanical components subjected to mechanical loading (Sadlon, 1993) and has been described as a simulative model of failure (Dasgupta and Pecht, 1991). 

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