In this paper application of a simulation algorithm for dynamic and nonlinear analysis of a specific liquid propellant engine is presented. The mathematical model of the engine includes a set of nonlinear algebraic equations which is coupled with a set of time varying differential equations. In contrast to the existing liquid propellant simulation algorithms, the presented work does not depend ...

In studying through simulation, choosing an appropriate tool/language would be a difficult task because many of them are available. On the other hand, few research works focus on evaluation of simulation tools/languages and their comparison. This paper makes a couple of evaluations and ranks more than fifty simulation tools that are currently available. The first evaluation and ranking is in th...

background: the monte carlo method is the most accurate method for simulation of radiation therapy equipment. the linear accelerators are currently the most widely used machines in radiation therapy centers. methods: in this work, a monte carlo modelling of the siemens oncor linear accelerator in 6 mv and 18 mv beams was performed. the results of simulation were validated by measurements in wat...

in this study, the effects of linear and rotational speed of the friction stir welding tool was investigated on the heat generation and distribution at surface and inside of workpiece, material flow and geometry of the welding area of poly methyl methacrylate (pmma) workpiece. the commercial cfd fluent 6.4 software was used to simulation of the process with computational fluid dynamic technique...

today according to the competitive conditions, companies try to reduce their inventory level to diminish the costs. in companies inventory management and control should establish a balance between inventory level of spare parts, cost and the risk that arising from absence of part when is needed. it is clear that this level of spare parts inventory affected by facility characteristics and its re...

dense medium cyclone is a high capacity device that is widely used in coal preparation. it is simple in design but the swirling turbulent flow, the presence of medium and coal with different density and size fraction and the presence of the air-core make the flow pattern in dmcs complex. in this article the flow pattern simulation of dmc is performed with computational fluid dynamics and fluent...

Markov Simulation and the more recent Poisson Simulation are two fully consistent ways of modelling, applicable to the same types of problems. A Markov model is based on a detailed description of every situation, called state, that a system can be in and every possible transition between these states. This approach allows powerful analysis and makes Markov models a fundamental part of the theor...

always allocate man - machine is considered as one of the main concerns of operation planners. utilize an appropriate using of workforce in situations that the operation is dependent on the capabilities of the workforce, can lead to improve the systems efficiency and productivity indicators. since these issues, categories in np-hard problems, so optimization and solving the mathematical model o...

In this paper, the particular solution technique for inverse simulation applied to the quadrotor maneuvering flight is investigated. The ‎trust-region dogleg (DL) technique which is proposed alleviates the weakness of Newton’s method used for numerical differentiation of system states in the solution process. The proposed technique emphasizes global convergence solution to the inverse simulatio...

many large oil and gas fields in the most productive world regions happen to be fractured. the exploration and development of these reservoirs is a true challenge for many operators. these difficulties are due to uncertainties in geological fracture properties such as aperture, length, connectivity and intensity distribution. to successfully address these challenges, it is paramount to improve ...