rade control structures are used to control bed erosion in steep small rivers mostly in the mountains. Scour downstream of this structure can lead to failure. Over the past years, the effect of different variables on this phenomena have been studied, however the effect of upward seepage which is common due to head difference of the banks water table or water surface level between the upstream a...

Improved understanding of mouth bar morphodynamics, and the resulting stratigraphic architectures, is important for predicting loci deposition different sediment fractions, coastal geomorphic change heterogeneity in reservoirs. Facies architectural analysis exceptionally well-exposed shallow water (ca 5 m depth) bars associated distributaries, from Xert Formation (Lower Cretaceous), Maestrat Ba...

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...

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,...

The generation of acoustic tones in four round jets at a Mach number 0.9 impinging on plate distance $L=6r_0$ from the nozzle exit, where $r_0$ is radius, has been investigated by large-eddy simulation. Three plates are perforated holes diameters $h=2r_0$ , $3r_0$ and $4.4r_0$ centred jet axis, whereas fourth no hole, order to study effects hole flow fields. In all cases, emerge near field, ups...

This paper describes the mechanism underpinning modal staging behaviour in screeching jets. An upstream-propagating subsonic guided-jet mode is shown to be active all stages of screech. Axial variation shock-cell spacing manifests spectral domain as a series suboptimal peaks. It demonstrated that may energized by interactions Kelvin–Helmholtz wavepacket with not only primary shock wavenumber pe...