in this paper, the transient inertial viscoelastic flow around a circular cylinder is investigated numerically. a second order finite-volume method is used to increase the numerical accuracy. here, the giesekus model is used as the constitutive equation. this nonlinear model has prominent ability in describing normal stress differences and viscosity in power-law regions. the impacts of the elas...

Heating is inevitable in any bearing operation. This leads to not only the thinning of the lubricant but also could lead to a thermal deformation of the bearing. The present work is an attempt to analyze the influence of thermal deformation on the thermohydrodynamic lubrication of infinitely long tilted pad slider rough bearings. As a consequence of heating the slider is deformed and is assumed...

Based on the Shliomis ferrofluid flow model (SFFM) and continuity equation for the film as well as porous region, modified Reynolds equation for lubrication of circular squeeze film bearings is derived by considering the effects of oblique radially variable magnetic field (VMF), slip velocity at the film-porous interface and rotations of both the discs. The squeeze film bearings are made up of ...

Although Darcy-Weisbach (D-W) equation has been accepted as a standard resistance equation in pressurized flow, some researchers and engineers still prefer to utilize Hazen-Williams (H-W) equation for analyzing water distribution networks (WDNs) in practice. The main difference between roughness coefficients of these two resistance equations is that D-W friction factor varies with Reynolds numb...

Nowadays, the Colebrook equation is used as a mostly accepted relation for the calculation of fluid flow friction factor. However, the Colebrook equation is implicit with respect to the friction factor (λ). In the present study, a noniterative approach using Artificial Neural Network (ANN) was developed to calculate the friction factor. To configure the ANN model, the input parameters of the Re...

Abstract: Detached-eddy simulation (DES) based on the v-f Reynolds-averaged Navier-Stokes (RANS) model is developed and tested. The v-f model incorporates the anisotropy of near-wall turbulence, which is absent in other RANS models commonly used in the DES community. The v-f RANS model is modi ed in order that the proposed v-f -based DES formulation reduces to a transport equation for the subgr...

Journal bearings in hermetic reciprocating compressors are analyzed experimentally as well as numerically. The motor current and the load applied to the bearing are measured to obtain the performance curve of the journal bearing, from which the critical Sommerfeld number is derived. In the numerical analysis, the Reynolds equation and equilibrium equations of the journal center are solved simul...

The global in time existence of strong solutions to the compressible Navier-Stokes equation around time-periodic parallel flows in R, n ≥ 2, is established under smallness conditions on Reynolds number, Mach number and initial perturbations. Furthermore, it is proved for n = 2 that the asymptotic leading part of solutions is given by a solution of one-dimensional viscous Burgers equation multip...

The relationship between the local temperature and the local heat flux has been established for the homogeneous hyperbolic heat equation. This relationship has been written in the form of a convolution integral involving the modified Bessel functions. The scale analysis of the hyperbolic energy equation has been performed and the dimensionless criterion for the mode of energy transport, similar...

Practical concept of velocity distribution of pressure flow in the bends is interesting and hence, the professional engineering design has been investigated in the current study. This paper shows that velocity distribution in the bends can be analyzed in terms of the probability distributions. The concept of entropy based on the probability is an applied and new approach to achieve velocity pro...