in this paper, the problem of turbulent forced convection flow of water- alumina nanofluid in a uniformly heated pipe has been thoroughly investigated. in numerical study, single and two-phase models have been used. in single-phase modeling of nanofluid, thermal and flow properties of nanofluid have been considered to be dependent on temperature and volume fraction. effects of volume fraction a...

The measurements of a turbulent swirl flow in the subchannels of a 5 x 5 rod array having typical mixing devices at the MATIS-H (Measurements and Analysis of Turbulence In SubchannelsHorizontal) facility have been analysed using a commercial CFD code of STAR-CCM+ 4.02 with a unit grid model having no unmatched grid interface. The main objectives of this analysis is to establish a proper CFD ana...

The regulation of turbulent transport by zonal flows is studied experimentally on a flux surface of the stellarator experiment TJ-K. Data of 128 Langmuir probes at different toroidal and poloidal positions on a single flux surface enable us to measure simultaneously the zonal flow activity and the turbulent transport in great detail. A reduction of turbulent transport by 30% during the zonal fl...

We present several observations into spiral turbulence in a Taylor-Couette geometry gained through a three-dimensional direct numerical simulation. Conditionally averaged flow statistics show the persistence of an azimuthal gradient of the mean flow across both the turbulent and laminar spirals, and distinct distribution features of the turbulent intensity. The data provide a physical picture q...

-A free-surface flow can change from a supercritical to subcritical flow with a strong dissipative phenomenon called a hydraulic jump. Herein the progress and development in turbulent hydraulic jumps are reviewed with a focus on hydraulic jumps operating at large Reynolds numbers typically encountered in natural streams and hydraulic structures. The key features of the turbulent hydraulic jumps...

in this paper, turbulent mixed convective heat transfer of water and al2o3 nanofluid has been numerically studied in a horizontal tube under non-uniform heat flux on the upper wall and insulation in the lower wall using mixture model. for the discretization of governing equations, the second-order upstream difference scheme and finite volume method were used. the coupling of pressure and veloci...

Turbulent flow over an array of wall-mounted cubic obstacles has been numerically investigated using large-eddy simulation. The simulations have been performed using high-performance computations with local cluster systems. The array of cubes are fully submerged in a simulated deep rough-wall atmospheric boundary-layer with high turbulence intensity characteristics of environmental turbulent fl...

The aim of this Letter is to characterize the flow regimes of suspensions of finite-size rigid particles in a viscous fluid at finite inertia. We explore the system behavior as a function of the particle volume fraction and the Reynolds number (the ratio of flow and particle inertia to viscous forces). Unlike single-phase flows, where a clear distinction exists between the laminar and the turbu...

This thesis describes the development and implementation of the turbulent flow tube technique, a new method for studying gas phase reaction kinetics. The plausibility of the turbulent flow tube technique has been examined using a numerical model. Several experimental studies of key fluid dynamical processes have also been performed. These experiments include flow visualization of reactant mixin...