Abstract The transition between the stable base state of magnetized spherical Couette (MSC) flow and return instability is experimentally investigated. experiments are conducted using an MSC setup consisting insulating spheres with ratio inner to outer radii r i / o = 0.5, Reynolds number Re 1000 Hartmann Ha ? [25, 29]. characterized by changes in power spectra azimuthal modes as dynamically ch...

The most important reason for the design of curved tubes is increasing the heat transfer between the fluid and the wall which has provided many applications in various industries such as air conditioning, micro-electric, heat exchangers and etc. The aim of this study is numerical investigation of nano fluids flow in spiral tubes with injection of base fluid in different Reynolds numbers. Accord...

CFD was applied to evaluate the performance of both existing and improved designs for refrigerant distributors. In general, it is better to utilize a spherical base as compared with other shapes and to locate the orifice close to distributor base. These changes tend to improve the robustness of the distributor in terms of providing even flow and phase distribution in different outlet branches w...

Floquet theory is used to describe the unstable spectrum at large scales of the βplane equation linearized about Rossby waves. Base flows consisting of one to three Rossby wave are considered analytically using continued fractions and the method of multiple scales, while base flow with more than three Rossby waves are studied numerically. It is demonstrated that the mechanism for instability ch...

This paper discusses the numerical simulations of selected high-speed aeropropulsive applications including axisymmetric supersonic base flowfields, with and without jets, and three-dimensional supersonic hot jets. Comparisons are made using a compressibility corrected k-ε turbulence model and an Explicit Algebraic Stress Model (EASM). The present EASM, referred to as EASM/J, has been modified ...

Hyporheic flow in streams has typically been studied separately from geomorphic processes. We investigated interactions between bed mobility and dynamic hyporheic storage of solutes and fine particles in a sand-bed stream before, during, and after a flood. A conservatively transported solute tracer (bromide) and a fine particles tracer (5 μm latex particles), a surrogate for fine particulate or...

land use change is one of the main factors in the process of changing the regime of flood in watersheds. taleghan watershed has been subjected to many land use changes over years, which probably effects on flood characteristics of taleghan river. in present study the effects of land use change on some parameters including peak flow, volume and flood base time, in part of taleghan basin, was inv...

In this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (GDL) of PEM fuel cell is modeled. The governing equations including energy, mass and momentum conservation equations are solved by numerical methods. Also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (GDL) thickness and inlet relative humidity are calculated...

In this study, the Brownian motion and thermophoresis effects on the MHD ferrofluid flow over a cone with thermal radiation were discussed. Kerosene with the magnetic nanoparticles (Fe3O4) was considered. A set of transformed governing nonlinear coupled ordinary differential equations were solved numerically using Runge-Kutta based shooting technique. A simulation was performed by mixing ferrou...