The generation of shock waves and their repercussions in high-speed vehicles are inevitable. Particularly, the hot plume from aircraft exhaust ejecting at a high speed, as well emitted aeroacoustic noise, have several consequences. Besides, occurrence supersonic core length emission screech noise mostly due to cells, prevailing jets. Therefore, understanding cell structures developed exit or ro...

We investigate experimentally the causes of jet plume instability and enhanced mixing observed in the exhaust of shock-containing convergent-divergent nozzles. Key features of the internal flow are the separation shock, separation shear layers, and pattern of alternating expansion and compression waves downstream of the shock. We focus on two possible reasons for this instability—the motion of ...

in this article, an algorithm for designing of a supersonic wind tunnel injection nozzle ejector is presented and based on this algorithm, a new ejector is designed for a supersonic wind tunnel. the injection nozzle consists of a volute, a nozzle, and several vanes. designed injection nozzle is simulated numerically, and the results are compared with the present injection nozzle. the results sh...

We propose in this paper a new curvature estimator based on the set of maximal digital circular arcs. For strictly convex shapes with continuous curvature fields digitized on a grid of step h, we show that this estimator is mutligrid convergent if the discrete length of the maximal digital circular arcs grows in Ω(h− 1 2 ). We indeed observed this order of magnitude. Moreover, experiments showe...

A linear stability analysis of the Rayleigh–Taylor instability RTI between two ideal inviscid immiscible compressible fluids in cylindrical geometry is performed. Three-dimensional 3D cylindrical as well as two-dimensional 2D axisymmetric and circular unperturbed interfaces are considered and compared to the Cartesian cases with planar interface. Focuses are on the effects of compressibility, g...

Ballistic simulation of the spray sprinkler for self-propelled irrigation machines requires the incorporation of the effect of the jet impact with the deflecting plate. The kinetic energy losses produced by the jet impact with the spray plate were experimentally characterized for different nozzle sizes and two working pressures for fixed spray plate sprinklers (FSPS). A technique of low speed p...

Abstract The article presents qualitative data on the study of process diffusion combustion during outflow a gas jet from nozzle apparatus with certain arrangement nozzles. is round straight channel and coaxially located annular slot. In experiments, hydrogen or methane was supplied through an slot, air central circular micro nozzle. main features are revealed comparison processes carried out. ...

The parametric representation and aerodynamic shape optimization of a three-dimensional circular-to-rectangular transition nozzle designed built using control lines distributed along the circumferential direction were investigated in this study. A surrogate model based on class/shape transformation, principal component analysis radial basis neural network was proposed with fewer design paramete...

A quasi one-dimensional analysis of a STOVL aircraft nozzle in hover is performed to estimate the gross thrust coefficient as a function of nozzle pressure and nozzle area ratios. The analysis is supported by subscale, cold flow test results. The nozzle performance was found to be less than desirable in hover due to the overexpansion arising from the geometrical constraints of the existing nozzle.