This study investigates the inviscid, linear spatio-temporal stability of heated, compressible and incompressible coaxial jet flows. The influence of the temperature ratio and the velocity ratio between the core jet and the bypass stream on the transition from convectively to absolutely unstable flows is studied numerically. The investigation shows that for coaxial jets absolute instability can...

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 role of waves in maintaining the midlatitude tropospheric climate is investigated in a dry high-resolution quasigeostrophic b-plane channel model coupled to both a simplified model of the atmospheric boundary layer and an interactive static stability. The climate of the model’s equilibrated state is found to be separated into two dynamical regimes, one within the boundary layer and the othe...

One of the world's major mineral dust source regions lies along the border between Iran and Afghanistan. In this studyit is hypothesized that a low-level jet may play in role in generating the intensity of this source region. The presence of alow-level jet east of the Seistan mountains is documented here for the first time. The jet exists mainly from May toSeptember and has a core at 850 mb. Ma...

[1] The use of a more physically based parametrisation scheme for sub-grid scale ocean mixing produces a more spatially uniform surface warming in the Southern Hemisphere in transient global warming simulations of the CCCma climate model than when an older scheme is used. Here we examine the effect of this different warming pattern on the tropospheric circulation response, by comparing simulati...

Linear features in a clear convective boundary layer (CBL) over the North Atlantic Ocean were studied during a weak cold air outbreak using a down-looking airborne lidar. Sequential lidar profiles were placed together and color coded to provide images of aerosol and molecular scattering from below the aircraft to the ocean surface, over a 36-km segment of a flight track approximately 150 km off...

The present work involves measurements to examine the effects of initial conditions on aerodynamic and acoustic characteristics of a Jet at M=0.8 by changing the orientation of sharp edged orifice plate. A thick plate with chamfered orifice presented divergent and convergent openings when it was flipped over. The centerline velocity was found to decay more rapidly for divergent orifice and that...