Pneumatic pulsator design as an example of numerical simulations in engineering applications

2015

Acta Mech

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An industrially applicable nozzle is the subject of this study. The nozzle is an auxiliary equipment of a pneumatic pulsator system for unclogging outlets of silos which store loose materials. The aim is to determine the amount of heat which is generated during one work cycle of the system. Investigation in this field has not been carried out so far, and the present-day designing process is significantly based on heuristic knowledge. The heat is calculated by using results of a numerical simulation. The Finite Volume Method has been used with a thermodynamically ideal gas model. The airflow is assumed to be transient, compressible and supersonic, and it is driven by a time-varying pressure difference. There is an estimation of discretization error of the numerical results carried out in order to confirm the reliability of the solution. The error estimation shows that the results lie in the vicinity of the exact solution of the governing equations. Instantaneous results of the simulation indicate a locally flow which intensifies flow parameters in a similar way as the convergingdiverging nozzles do. The value of the total heat generated during gas conversion within the nozzle is negative; thus, the nozzle could be cooled during its functioning.

Section: List Of Symbolsmentioning

confidence: 99%

On the heat in the nozzle of the industrial pneumatic pulsator

2015

Acta Mech

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“…The generation of vaults in loose material is always a cause of transportation intervals, energy costs increasing, and costs related to work safety. Research and Development has already been carried out on the device for making silos outlets clear and it has been reported in [5] and then continued in [6]. This paper presents next step in the development of a whole system for silo outlets clearance.…”

Section: Introductionmentioning

confidence: 96%

ICEEM07: Three-Dimensional Flow Optimization of a Pneumatic Pulsator Nozzle with a Continuous Adjoint

International Journal of Nonlinear Sciences and Numerical Simulation

2015

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The article presents results of multi-criteria optimization of air nozzle topology. The optimization in the Computational Fluid Dynamics (CFD) has been recently developed since equations of flow in porous media were applied among others governing equations. Optimization is a seeking for extremum of an objective function with respect to the function constraints. With this definition in mind, the optimization by using a continuous adjoint for the current cases is a finding such channel topology which minimizes for example pressure or energy loss when the constraints of objective function are in the form of flow governing equations of momentum and continuity. This methodology of optimization makes a design process faster comparing to the methods related to Design of Experiments (DoE). However, for the sake of flow governing equations nonlinearity, the continuous adjoint method can be successfully applied only in relatively simply and steady-state cases. The method consists in seeking of a global extremum of objective function. This extremum can sometimes be find in only simple and stationary events. The results of optimization of two selected cases are presented in the article and show advantages and limitations of the method applied. The continuous adjoint simulation results indicate the nozzles design directions and can be applied in industry with limited reliability. The object of research reported in the article is the nozzle which is augmented equipment used with a pneumatic pulsator. The pulsators are devices that utilize an air stream to destruct vaults created in loose material structure. The pulsator productivity equipped with a nozzle depends on outlet pressure. Therefore, the optimization problem was stated so that pressure loss is to be as low as possible.

“…Aiming to reduce the cost and increase the efficiency of the transport and storage of material has resulted in a large number of effective solutions. One of the devices that can prevent the undesirable phenomena is the pneumatic pulsator [3]. Particularly important is the use of pneumatic pulsators in the energy and cement industry.…”

Section: Introductionmentioning

confidence: 99%

Study of Heat Transfer in Pneumatic Pulsator

2015

AMM

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The article presents selected results of research work aimed to rationalize and optimize the design of the pneumatic pulsator due to thermal conditions. Pneumatic pulsator is a device used in industry storing bulk and loose materials. It is attached to the silo, allowing their correct operation. The air friction against the inner wall of the pulsator causes the release of heat. In order to investigate the conditions of heat transfer, thermal calculations were made and then numerical simulations using Computational Fluid Dynamics (CFD) were conducted. Various fins options were examined. The objective was to maximize the heat flux discharged from the device. Temperature distribution on the surface of the fins designated by CFD corresponds to the distribution designated analytically. The results were confirmed by industrial tests. Numerical simulations mapping the heat exchange processes in a pneumatic pulsator have not yet been carried out.