Cavitation and turbulence in a diesel injector nozzle has a great effect on the development and primary breakup of spray. However, the mechanism of the cavitation flow inside the nozzle and its influence on spray characteristics have not been clearly known yet because of the internal nozzle flow complexities. In this paper, a comprehensive numerical simulation is carried out to study the intern...

<p style='text-indent:20px;'>This paper focuses on two-dimensional continuous subsonic-sonic potential flows in a semi-infinitely long nozzle with straight lower wall and an upper which is convergent at the outlet while far fields. It proved that if variation rate of cross section suitably small, there exists unique such sonic curve intersects fixed point velocity flow along normal direct...

DLR Lampoldshausen carried out cold flow tests to study the flow field in a truncated ideal contour nozzle at low nozzle pressure ratios. A convex shaped Mach disk was found for nozzle pressure ratios less than 10 and a slight concave one for nozzle pressure ratios more than 20. Due to boundary layer transition the convex Mach disk is temporary tilted and redirects the flow towards the nozzle w...

Vortex breakdown of swirling, round jet flows is investigated in the compressible, subsonic regime by means of Direct Numerical Simulation (DNS). This is achieved by solving the compressible Navier–Stokes equations on a cylindrical grid using high-order spatial and temporal discretization schemes. The Reynolds number is Re = ρ c w ◦ c R ◦/μ◦c = 5000 and the flow is moderately compressible with ...

This report describes an application of a digital computer to the aerodynamic design and automatic control of a large wind tunnel with flexible walls. The computational problem was threefold : first, calculation of the wall shapes for a set of 'pivotal' operating speeds between M = 1 and 2"8; second, computation of the necessary movements of the set of screw jacks which flex the walls ; and fin...

This study evaluates the role of shock wave motion on the instability of the plume exiting an over-expanded, convergent-divergent nozzle. An array of wall pressure transducers was used to track the position of the shock in time, and a Pitot probe was used to obtain simultaneous measurement of the total pressure fluctuations at various points in the jet that emerges from the separation shock. An...

A Southwest Electrostatic Sprayers, Inc., nozzle was configured to a Hudson PortaPak backpack. A test was run to compare deposition of BVA no. 13 oil by the electrostatic nozzle to a standard nonelectrostatic nozzle as collected by Teflon slides. Results indicate that 100% greater deposition occurred with the electrostatic nozzle.

this experiment was conducted to study the effect of nozzle types and the time of herbicide incorporation in soil on weed control, using split plot design by randomized block design. the main plots were soil and herbicide mixing time and the subplots were nozzle types with three replications. this study was performed in karaj station of seed and plant improvement institute, located 25 km west o...

An axisymmetric full Navier-Stokes computational fluid dynamics study is conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock research airplane, is considered. The computational fluid dynamics code i...

This paper reports on the simulation of the near-nozzle region of a moderate Reynolds number cold jet flow exhausting from a chevron nozzle. The chevron nozzle considered in this study is the SMC001 nozzle experimentally studied by the researchers at the NASA Glenn Research Center. This nozzle design contains six symmetric chevrons that have a five-degree penetration angle. The flow inside the ...