in this research, the frequency of the jet streams associated with extreme and pervasive precipitation has been analyzed using environmental to circulation approach. based on the 99th percentile index, 109 days of the extreme and pervasive precipitation was selected from the irimo data base ( including 33 synoptic, climatic and rain gage stations during 15992 days from farvardin, 1st, 1340 to d...

numerous investigations have been devoted towards understanding the hydrodynamics of gas jets in fluidized beds. however, most of them address the problem from  macroscopic point of view, which does not reveal the true behavior in the jet region at the single particle level. the present work aims to understand the jet behavior from a more fundamental level, i.e. the individual particle level. a...

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.

Arc jets are unique facilities used to evaluate the performance of Thermal Protection Systems (TPS) for hypersonic vehicles. They produce high pressure and enthalpy plasma flow simulate extreme heat encountered during atmospheric entry. The constricted arc heater part an jet increases test gas temperature by Joule heating. This study details development three-dimensional unsteady analysis tool,...

Using of nanofluids and ducts with corrugated walls are both supposed to enhance heat transfer, by increasing the heat transfer fluid conductivity and the heat transfer area respectively. Use of a diverging duct with a jet at inlet section may further increase heat transfer by creating recirculation zones inside the duct. In this work two-dimensional incompressible laminar flow of a nanofluid e...

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...

introduction jet stream is strong narrow current concentrated by strong vertical and lateral wind shears (vasantha et al, 2002). according to world meteorological organization nomenclature, jet stream formed when the speed of wind greater than 60 knots or 30 m/s. the major characteristics of the troposphere and lower stratosphere in the vicinity of jet streams were pointed out by a group of met...

BACKGROUND Needle cricothyrotomy and subsequent transtracheal jet ventilation (TTJV) is one of the last options to restore oxygenation while managing an airway emergency. However, in cases of complete upper airway obstruction, conventional TTJV is ineffective and dangerous. We transformed a small, industrial ejector into a simple, manual ventilator providing expiratory ventilation assistance (E...