Document Type : Research Article
Authors
1
Department of Chemical Engineering, Shahrood Branch, Islamic Azad UniversityShahrood3619943189, I. R. IRAN.
2
Multidisciplinary Research Center for Innovations in SMEs (MrciS), GISMA University of Applied Sciences, 14469 Potsdam, Germany
3
Department of mechanical engineering, Shahrood University of Technology, Shahrood, I. R. IRAN
4
Shahrood branch, Islamic Azad University, Shahrood, Iran
5
Shahrood Branch, Islamic Azad University
6
Department of Mechanical Engineering, Shahrood Branch, Islamic Azad University, Shahrood3619943189, I. R. IRAN
7
Department of Mechanical Engineering, Technical and Vocational University (TVU), Mashhad, Iran.
8
Department of Civil Engineering, Shahrood Branch, Islamic Azad University, Shahrood3619943189, I. R. IRAN
Abstract
The unsteady, viscous flow of Nanofluid in the vicinity of an axisymmetric stagnation point of an oscillating cylinder is investigated. The cylinder is moving toward or away from the impinging flow. The impinging free-stream is steady and with a constant strain rate . Self similar solution of the Navier–Stokes equations is derived in this unsteady problem. A reduction of these equations is obtained by use of appropriate transformations introduced for the first time. All the solutions above are presented for Reynolds numbers ranging from 1 to 2000, selected values of dimensionless time and selected values of particle fractions where is cylinder radius and is kinematic viscosity of the base fluid. For all Reynolds numbers, as the particle fraction increases, the depth of diffusion of the fluid velocity field in radial direction, the depth of the diffusion of the fluid velocity field in -direction, and shear-stress decreases. Furthermore, it has been determined that the maximum dimensionless shear stress is 370, which corresponds to a volume fraction of 0.05 and T* = 0.45. Additionally, for all volume fractions, the maximum and minimum values of the hydrodynamic boundary layer thickness are associated with T* = 0.75 and T* = 0.45, respectively. The problem is particularly important in pressure-lubricated bearings.
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