Multiwaveband images of extended jets in quasars reveal that in some locations electrons reach energies of at least 100 TeV, while in others the particle acceleration is less efficient. The jet of the quasar 1317+520 (z=1.06) contains shocks that are both transverse and oblique to the jet axis as well as regions where the axial magnetic field and polarization indicate cross-jet velocity shear. ...

numerical study has been carried out for slot air jet impingement cooling of horizontal concentric circular cylinders. the slot air jet is situated at the symmetry line of a horizontal cylinder along the gravity vector and impinges to the bottom of the outer cylinder which is designated as θ=0°. the outer cylinder is partially opened at the top with width of w=30mm and is kept at constant tempe...

A plane subsonic jet was subjected to periodic oscillations in the near nozzle region by a twin vane system. During excitation, the jet was found to spread significantly and entrain mass much more than its steady counterpart. Time averaged static pressure measured in the flow field with a disc probe exhibited prominent well defined suction regions different from that of a steady jet.

Fast liquid jets, called micro-jets, are produced within cavitation bubbles experiencing an aspherical collapse. Here we review micro-jets of different origins, scales and appearances, and propose a unified framework to describe their dynamics by using an anisotropy parameter ζ > 0, representing a dimensionless measure of the liquid momentum at the collapse point (Kelvin impulse). This paramete...

Archer fish knock down insects anchored to vegetation by hitting them with a precisely aimed jet of water. The striking force of the jet at the impact is such to overcome the strong anchoring forces of insects. The origin of the effectiveness of such hunting mechanism has been long searched for inside of the fish, in the unsuccessful attempt to identify internal structures dedicated to the ampl...

An axisymmetric jet issued from a sharp edged circular convergent nozzle has been studied experimentally in the near field at Reynolds number 5.3x104  to search the saddle shape behavior of mean velocity and the role of mean static pressure in the jet flow. Due to the vena contracta effect the centerline mean velocity of the jet increases about 4.2% of its exit value and corresponding decrease ...

the effect of a combined system of the bed suction and jet injection as a pier-scour countermeasure on the turbulent flow field is studied in a laboratory flume using an acoustic doppler velocimeter (adv). the three components of the velocities in the vertical symmetry plane in the equilibrium scour hole in front and rear of the pier under 3-jet injections and bed suction rate qs/q0 = 2%located...

The effect of a combined system of the bed suction and jet injection as a pier-scour countermeasure on the turbulent flow field is studied in a laboratory flume using an Acoustic Doppler Velocimeter (ADV). The three components of the velocities in the vertical symmetry plane in the equilibrium scour hole in front and rear of the pier under 3-jet injections and bed suction rate Qs/Q0 = 2%located...