The present paper describes the verification and validation of a quasi one-dimensional pressure based finite volume algorithm, implemented in Generalized Fluid System Simulation Program (GFSSP), for predicting compressible flow with friction, heat transfer and area change. The numerical predictions were compared with two classical solutions of compressible flow, i.e. Fanno and Rayleigh flow. Fa...

The aim of this work is to determine the supersonic nozzle profiles used in propulsion, for the launchers or embarked with the satellites. This design has as a role firstly, to give a important propulsion, i.e. with uniform and parallel flow at exit, secondly to find a short length profiles without modification of the flow in the nozzle. The first elaborate program is used to determine the prof...

Magnetic Resonance Imaging (MRI) is a non-invasive, three-dimensional imaging technique capable of measuring optically opaque media. Its signal can be sensitized to many parameters (velocity, diffusion/mechanical dispersion, air-liquid boundaries, etc). It is most sensitive where the sample’s density is the highest, i.e., inside the spray nozzle and in the near-nozzle regions; these are also re...

A continuous near-field electrospray process has been developed to deposit micropatterns. Different from traditional electrospray technologies, the nozzle-to-substrate distance was shortened to less than 5 mm, and a glass capillary nozzle with a diameter of tens of microns was used. Steady and continuous ejection was achieved, and patterns with line widths of sub-100 μm were generated. The infl...

Waterjet breakup is traditionally considered to follow the Ohnesorge classification. In this classification, high Reynolds number waterjets are considered to atomize quickly after discharge. By generating a constricted waterjet where the water flow stays detached all the way through the nozzle, we have observed the first wind-induced breakup mode at high Reynolds numbers. Such a peculiar behavi...

The quality of continuous-cast steel is greatly influenced by fluid flow in the mold, particularly at the meniscus. Recent examples of computational model applications at the University of Illinois are presented to investigate the formation of several different types of defects related to flow phenomena. The amount of gas injection into the tundish nozzle to avoid air aspiration is quantified b...

The purpose of this study was to develop and evaluate the flow rate, spray pattern, and droplet spectra characteristics of an actively controlled variable-orifice nozzle at constant carrier pressures. A commercially available variable-orifice nozzle (VariTarget) was modified to allow for direct electromechanical control of the metering stem. The modified system was tested at five carrier pressu...

A numerical analysis is carried out to determine the flowfield and starting characteristics of a straight cylindrical supersonic exhaust diffuser of a high-altitude simulation of a high expansion ratio rocket nozzle. The flow field inside the high-altitude facility is analyzed for a conical nozzle of expansion ratio of 25, diffuser inlet-to-nozzle throat area ratio of 28.9, and diffuser length-...

A series of coaxial dual-stream jets issuing into quiescent air was investigated using Reynolds-averaged Navier-Stokes calculations with linear two-equation and nonlinear two-equation explicit algebraic stress turbulence modeling. Comparisons of calculated mean flowfield development were made with experimental data. For all cases, a single axisymmetric convergent-divergent nozzle provided a Mac...

Spray deposition and distribution are affected by many factors, one of which is nozzle flow distribution. A two-dimensional automatic measurement system, which consisted of a conveying unit, a system control unit, an ultrasonic sensor, and a deposition collecting dish, was designed and developed. The system could precisely move an ultrasonic sensor above a pesticide deposition collecting dish t...