SUMMARY The linear spatial stability of a mixing layer between two parallel streams is considered, and a comparison is made between the stability of flows with and without a stationary splitter plate separating them upstream. The assumed velocity profile satisfies the condition of no slip on the splitter plate, but in other respects the flow is treated as inviscid. Account is taken of the jet s...

A liquid jet can stably bounce off a sufficiently soft gel by following the contour of the dimple created upon impact. This new phenomenon is insensitive to the wetting properties of the gels and was observed for different liquids over a wide range of surface tensions, γ=24-72  mN/m. In contrast, other jet rebound phenomena are typically sensitive to γ: only a high γ jet rebounds off a hard sol...

In this paper, the acoustic excitation effects on the flow characteristics of a laminar jet inside an air-filled cylindrical tube have been presented and discussed. It is observed that the acoustic excitation has a strong effect on the jet velocity and its flow structure. Under excitation, the velocity is observed to increase more than seven times. Comparisons and investigations of the velocity...

In plunging jet flows and at hydraulic jumps, large quantities of air are entrained at the intersection of the impinging flow and the receiving body of water. The air bubbles are entrained into a turbulent shear layer and strong interactions take place between the air bubble advection/diffusion process and the momentum shear region. New air-water flow experiments were conducted with two free sh...

This paper aims to present some perspectives on mapping embouchure gestures of flute players and their use as control variables. For this purpose, we have analyzed several types of sensors, in terms of sensitivity, dimension, accuracy and price, which can be used to implement a system capable of mapping embouchure parameters such as air jet velocity and air jet direction. Finally, we describe t...

The ambient air is entrained intensively into atmospheric pressure thermal plasma jets. A system for shielding plasma jet has been used to improve jet characteristics and reduce oxygen content. Different gases have been applied as a shroud gas – argon, acetylene, methane, mixtures of acetylene-nitrogen and hydrogen-nitrogen. All shroud gases used in experiments affected plasma jet making the pr...

Jet fans are applied for control of air flow and support of pollutant dispersal in large enclosures. In The Netherlands, application is well known for car parks as part of the fire safety design. In the design phase often the Computational Fluid Dynamics (CFD)-technique is used to verify the fire safety level afforded by the application of jet fans. However, very little is known on the modellin...

It was shown in recent work that the crests of surface disturbances on a falling jet are a powerful agent for air entrainment at the free surface of a liquid pool. The paper explores the opposite case in which the jet is disturbed so as to form an axisymmetric trough, rather than a crest. It is found that no air is entrained in this case. The paper concludes with some considerations on the vali...

Influence of air entrainment on rock scour development and block stability in plunge pools The impingement of high-velocity water jets on plunge pools, such as it occurs downstream of spillways of high-head dams, may cause scour on the rock foundations. The scour process is the result of complex and consecutive physical phenomena. Turbulence plays a major role, especially in the jet development...