Fluid Flow in Composite Cylindrical Regions

2021 ◽  
Vol 40 ◽  
pp. 63-72
Author(s):  
R. Umadevi ◽  
D.V. Chandrashekhar ◽  
P.A. Dinesh ◽  
D.V. Jayalakshmamma

A steady, 2-D, viscous fluid flow past a fixed solid cylinder of radius ‘a’ has been considered where the density is constant for considered fluid. The flow of fluid happens in 3 regions namely fluid, porous and fluid region. The constitutive equations for the flow in porous and fluid regions are Brinkman and Stokes equations respectively. The variation of flow patterns by means of streamlines has been analysed by applying different boundary conditions at the interface of fluid – porous and porous – fluid regions and also on the surface of the solid cylinder assuming that the even velocity far off from the fluid region. The nature of streamlines is observed for the distinct values of porous parameter ‘σ’ and the corresponding flow behaviour is analysed graphically. From the obtained results it is noticed that increase in porous parameter, suppress the fluid flow in porous region consequently the fluid moves away from the solid cylinder.

2019 ◽  
Vol 9 (1) ◽  
pp. 119-125
Author(s):  
Evgeny A. KRESTIN

In order to reduce the energy consumption, increase the reliability of the hydraulic drive of construction machines and mechanisms, studies of the hydrodynamic parameters of the viscous fluid flow in a flat diffuser during the oscillation of one of the walls of the channel are carried out. Navier-Stokes equations together with the continuity equation are used to construct velocity and pressure fields. The problem is solved in polar coordinates with boundary conditions. The General solution of the problem, which corresponds to the self-similar boundary condition on the moving wall, is obtained. The radial velocity profile has sections of forward and reverse currents and is a standing wave along the angular coordinate. The forces acting on the movable and stationary walls of the diffuser are determined.


2019 ◽  
Vol 8 (1) ◽  
pp. 695-701 ◽  
Author(s):  
Amit Prakash ◽  
Doddabhadrappla Gowda Prakasha ◽  
Pundikala Veeresha

Abstract In this paper, numerical solution of fractional order Navier-Stokes equations in unsteady viscous fluid flow is found using q-homotopy analysis transform scheme. Fractional derivative is considered in Caputo sense. The proposed technique is a blend of q-homotopy analysis scheme and transform of Laplace. It executes well in efficiency and provides h-curves that show convergence range of series solution.


2021 ◽  
Author(s):  
Takashi Hotta

Abstract The minimum entropy theorem of the several fields is well known, but there is no clear review that it shows the possibility of minimum entropy theorem mainly rules the general viscous fluid flow field. In this article, I define appropriately total external energy function and is resolved by variational method, and shows that stationary condition always satisfies the continuity and general Navier-Stokes equations. So on that condition, the minimum entropy theorem could decide directly the general viscous fluid flow field.


Author(s):  
Yi Shi ◽  
Jianjun Zhu ◽  
Haoyu Wang ◽  
Haiwen Zhu ◽  
Jiecheng Zhang ◽  
...  

Assembled in series with multistage, Electrical Submersible Pumps (ESP) are widely used in offshore petroleum production due to the high production rate and efficiency. The hydraulic performance of ESPs is subjected to the fluid viscosity. High oil viscosity leads to the degradation of ESP boosting pressure compared to the catalog curves under water flow. In this paper, the influence of fluid viscosity on the performance of a 14-stage radial-type ESP under varying operational conditions, e.g. rotational speeds 1800–3500 r/min, viscosities 25–520 cP, was investigated. Numerical simulations were conducted on the same ESP model using a commercial Computational Fluid Dynamics (CFD) software. The simulated average pump head is comparable to the corresponding experimental data under different viscosities and rotational speeds with less than ±20% prediction error. A mechanistic model accounting for the viscosity effect on ESP boosting pressure is proposed based on the Euler head in a centrifugal pump. A conceptual best-match flowrate QBM is introduced, at which the impeller outlet flow direction matches the designed flow direction. The recirculation losses caused by the mismatch of velocity triangles and other head losses resulted from the flow direction change, friction loss and leakage flow etc., are included in the model. The comparison of model predicted pump head versus experimental measurements under viscous fluid flow conditions demonstrates good agreement. The overall prediction error is less than ±10%.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Zubair Akbar Qureshi ◽  
S. Bilal ◽  
M. Y. Malik ◽  
Qadeer Raza ◽  
El-Sayed M. Sherif ◽  
...  

AbstractMatrix nanocomposites are high performance materials possessing unusual features along with unique design possibilities. Due to extraordinary thermophysical characteristic contained by these matrix nanocomposites materials they are useful in several areas ranging from packaging to biomedical applications. Being an environment friendly, utilization of nanocomposites offer new technological opportunities for several sectors of aerospace, automotive, electronics and biotechnology. In this regards, current pagination is devoted to analyze thermal features of viscous fluid flow between orthogonally rotating disks with inclusion of metallic matrix nanocomposite (MMNC) and ceramic matrix nanocomposites (CMNC) materials. Morphological aspects of these nanomaterials on flow and heat transfer characteristics has been investigated on hybrid viscous fluid flow. Mathematical structuring of problem along with empirical relations for nanocomposites materials are formulated in the form of partial differential equations and later on converted into ordinary differential expressions by using suitable variables. Solution of constructed coupled differential system is found by collaboration of Runge–Kutta and shooting methods. Variation in skin friction coefficient at lower and upper walls of disks along with measurement about heat transfer rate are calculated against governing physical parameters. Impact of flow concerning variables on axial, radial components of velocity and temperature distribution are also evaluated. Contour plots are also drawn to explore heat and thermal profiles. Comparison and critical analysis of MMNc and CMNc have been presented at lower and upper porous disks. Our computed analysis indicates that hybrid nanofluids show significant influence as compared to simple nanofluids with the permutation of the different shape factors.


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