The unsteady viscous flow in the vicinity of an axisymmetric stagnation point of an infinite moving cylinder with time-dependent axial velocity is investigated. The impinging free stream is steady with a strain rate k. An exact solution of the Navier-Stokes equations is derived in this problem. A reduction of these equations is obtained by use of appropriate transformations. The general self-si...

In this study, a white light particle image velocimetry (WL PIV) system which employs a light sheet generated with a flash was used. The system was developed in order to provide a cost-efficient and safe alternative to laser systems while keeping the accuracy limits required for hydraulic model tests. To investigate the accuracy of WL PIV method under different flow conditions, experiments were...

Hydrodynamic of a turbulent impinging jet on a flat plate has been studied experimentally and numerically. Experiments were conducted for the Reynolds number range of 72000 to 102000 and a fixed jet-to-plate dimensionless distance of H/d=3.5. Based on the experimental setup, a multi-phase numerical model was simulated to predict flow properties of impinging jets using two turbulent models. Mesh...

The purpose of this work is to compare di erent low-Reynolds-number turbulence models and their suitability for the highly three dimensional return channel with a deswirl cascade. A comparison is made between Chien's k model, Chien's model with a rotational correction, Gatski et al. ARSM and the full Reynolds stress model by Speziale et al.. Experiments are provided by Concepts ETI. MAIN RESULT...

Numerical predictions of blood flow patterns and hemodynamic stresses in Abdominal Aortic Aneurysms (AAAs) are performed in a two-aneurysm, axisymmetric, rigid wall model using the spectral element method. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-averaged Reynolds numbers 50< or =Re(m)< or =300, corresponding to a range of peak Re...

Particle-image velocimetry experiments are performed to study the response of smooth-wall turbulent channel flow to a short fetch of roughness (10 outer length scales long). The roughness studied herein is replicated from a surface scan of a damaged turbine blade and contains both largeand small-scale surface defects attributable to pitting, deposition, and spallation. Quadrant analysis is used...

Using numerical MHD simulations, we have studied the evolution of the magnetorotational instability in stratified accretion disks in which the ionization fraction (and therefore resistivity) varies substantially with height. This model is appropriate to dense, cold disks around protostars or dwarf nova systems which are ionized by external irradiation of cosmic rays or high-energy photons. We f...

We develop a methodology to ensure that the stress tensor, regardless of its number of independent components, can be reduced to an exactly equivalent one which has the same number of independent components as the surface force. It is applicable to the momentum balance if the shear viscosity is constant. A direct application of this method to the energy balance also leads to a reduction of the ...

this paper describes the effects of induced magnetic field and partial slip on the peristaltic flow of a couple stress fluids in an asymmetric channel. the two dimensional equation of couple stress fluid are simplified by making the assumptions of long wave length and low reynolds number. the exact solutions of reduced momentum equation and magnetic force function have been computed in wave fra...