Current Issue : January - March Volume : 2018 Issue Number : 1 Articles : 5 Articles
We investigate the accuracy and the computational efficiency of the numerical schemes for evaluating fluid forces in Cartesian\ngrid systems. A comparison is made between two different types of schemes, namely, polygon-based methods and mesh-based\nmethods, which differ in the discretization of the surface of the object. The present assessment is intended to investigate the effects\nof the Reynolds number, the object motion, and the complexity of the object surface.The results show that the mesh-based methods\nwork as well as the polygon-based methods, even if the object surface is discretized in a staircase manner. In addition, the results\nalso show that the accuracy of the mesh-based methods is strongly dependent on the evaluation of shear stresses, and thus they\nmust be evaluated by using a reliable method, such as the ghost-cell or ghost-fluid method....
In this article, effect of a time-dependent\nstenosis on the flow of a non-Newtonian fluid through\nporous medium in axially symmetric constricted tube is\nanalyzed using integral method. The study is based on a\nsecond grade fluid model. An order of magnitude analysis\nis performed to simplify the model for mild constriction.\nIntegral approach coupled with the fourth-order polynomial\nsolution for the velocity profile is used. The effect of\ndifferent non-dimensional parameters such as Reynolds\nnumber, non-Newtonian parameter, porous parameter and\ntime emerging in the model on velocity profile, pressure\ngradient, wall shear stress, separation and reattachment\ndata are presented and discussed graphically. Velocity of\nthe fluid increases with an increase in time, while with the\nincrease in porous parameter velocity of the fluid decreases.\nIt is noted that Reynolds number provides a mechanism\nto control the attachment and de-attachment points for\ndifferent values of porous parameter. The present study is\nvalid only for mild stenosis....
Under the conditions of high demand for energy saving and environmental protection,\nthe thermal power unit is required to phase out the traditional extensive operation modeââ?¬â?a method of\noxygen-enriched combustion in a furnace, considering safety first. Achieving efficient and economic\noperation with an optimal proportion of air distribution in these thermal power units is crucial.\nThe high-precision simulation equipment could provide an experimental basis for optimal operation\nof field units. This paper starts by improving the accuracy of simulation equipment. In this work,\nthe method of dividing nodes and branches in the boiler was based on signal flow graph theory.\nAccording to the flow characteristics of the working substance, the method for calculating the node\nand branch pressure drop was analyzed and set up. Subsequently, a fluid network model of the\nmulti-dimensional flue gas system was constructed. With the help of our self-developed simulation\nmodel and data-driven platform, a modular simulation algorithm was designed. The simulation\nanalysis of the boiler showed the accuracy of the model....
Flow condition was simulated in a shaft tubular pump by using the Shear-Stress Transport (SST) ...
We propose two friendly analytical techniques called Adomian decomposition and Picard methods to analyze an unsteady\naxisymmetric flow of nonconducting, Newtonian fluid. This fluid is assumed to be squeezed between two circular plates passing\nthrough porous medium channel with slip and no-slip boundary conditions. A single fractional order nonlinear ordinary\ndifferential equation is obtained by means of similarity transformation with the help of the fractional calculus definitions. The\nresulting fractional boundary value problems are solved by the proposed methods. Convergence of the two methods� solutions is\nconfirmed by obtaining various approximate solutions and various absolute residuals for different values of the fractional order.\nComparison of the results of the two methods for different values of the fractional order confirms that the proposed methods are\nin a well agreement and therefore they can be used in a simple manner for solving this kind of problems. Finally, graphical study\nfor the longitudinal and normal velocity profiles is obtained for various values of some dimensionless parameters and fractional\norders....
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