Cavitation bubbles accompany explosive vaporization of water following pulsed energy deposition in liquid media. Bubbles collapsing at the tip of a surgical endoprobe produce a powerful and damaging water jet propagating forward in the axial direction of the probe. We studied interaction of such jet with tissue using fast flash photography and modeled the flow dynamics using a two-dimensional R...

several investigations have been devoted towards understanding the coating process in fluidized beds. most of these studies focused on spraying liquid droplets over the bed. however, due to the complexity of these systems, more investigations are still required to quantify the effect of operating conditions on the coating criteria. the present work aims at fundamentally understanding and precis...

Recently, particular attention has been paid to the stepped spillways due to the increasing effect of energy dissipation and the reduction of cavitations risks with the development of Roller Compacted Concrete (RCC) technique. Flow regimes on the spillways divide into three groups, namely skimming, jet and transition flow. Compared to the numerical methods, the majority of performed studies in ...

The paper presents large eddy simulation of unconfined swirling jets. In the first part, an unconfined annular jet is investigated for swirl numbers ranging from 0 to 1.2. The impact of the swirl on the mean flow and the precessing vortex structures in this flow is analysed. In the second part of the paper, a co-annular pilot jet is introduced near the axis. The investigations show that the add...

A direct numerical simulation of a round under-expanded sonic jet in turbulent supersonic cross flow has been carried out. The objective is to investigate the mixing mechanism which occurs downstream the jet by use of a passive scalar variable. The Navier-Stokes equations in the cylindrical geometry are solved by use of multiblock overlapping meshes. The method has been validated with a laminar...

The thermal effect of cool jets issuing into an incompressible hot cross flow at an angle over a turbine blade is the subject. Numerical solutions for twelve multiple flow arrangements with two flow ratios, two different hole spacing and four different jet issuing angles document strong to moderate secondary vortex structures spanning normal to the direction of the jet. This fully three-dimensi...

In the present paper the characterization of the flow field generated by means of a submerged gaseous jet exited by means of a coaxial synthetic jet has been investigated. The purpose of this investigation is to infer the aerodynamic interaction of the two fluid structures that play an interesting role in several industrial applications like jet actuator, flame stability in the combustor for mi...

An expansion in terms of the ratio lambda of the characteristic crossflow velocity U infinity to jet velocity Uj, where lambda=U infinity/Uj<<1, is used to obtain a representation of the basic three-dimensional steady flow in the nearfield of a transverse jet at large Reynolds numbers and to study its dominant instability. The inviscid vortex sheet analysis of Coelho and Hunt is extended so as ...

Numerical simulations of unsteady flow in a Hartmann resonance tube are carried out with the goal of understanding the effect of jet Mach number on the flow characteristics. The device, which consists of a convergent nozzle facing a closed end tube produces a nearly normal shock that fluctuates in the gap between the nozzle and the tube. Numerical solutions were obtained for the unsteady Reynol...

Ejectors have been widely used in many applications such as water desalination, steam turbine power generation, refrigeration systems, and chemical plants. The advantage of an ejector system lies in its extremely reliable and stable operation due to the complete absence of moving parts. However, the performance depends on a number of factors, among which the flow channel configuration/arrangeme...