We present systematic studies on the absolute density of hydrogen cluster beams produced by using Laval-nozzles. Measurements of the cluster beam density as function of the nozzle temperature and the gas input pressure result in maximum cluster beam densities for cases where the gas is already in a supersaturated state before passing the nozzle. The influence of the gas flow through the nozzle ...

Samplers are characterized at ECBC using the following methods: (1) monodisperse fluorescent/nonfluorescent PSL microspheres with fluorometric analysis or Counter analysis, (2) polydisperse solid aluminum oxide particles with APS analysis or Coulter Multisizer analysis, (3) fluorescent oleic acid particles with fluorometric analysis, and (4) bioparticles with Coulter Multisizer, culturing, ELIS...

Distributions of nitric oxide vibrational temperature, rotational temperature and velocity have been measured in the hypersonic freestream at the exit of a conical nozzle , using planar laser-induced fluorescence. Particular attention has been devoted to reducing the major sources of systematic error that can affect fluorescence temperature measurements, including beam attenuation, transition s...

A numerical study of three-dimensional effects on the performance of a micronozzle fabricated from  at silicon wafers is performed by use of both continuum and kinetic approaches. The nozzle operates in a low-Reynoldsnumber regime, and viscous effects dominate the gas expansion. Thrust losses occur because the shear on the wall is greater in a  at nozzle conŽ guration than in an axisymmetric ...

in this research mass transfer coefficient under jetting regime in different directions (from dispersed to continuous and continuous to dispersed phase) has been studied using an experimental setup. n-butanol-succinic acid-water with low interfacial tension has been selected as experimental chemical system. the effects of various parameters such as jet velocity, nozzle diameter and the height o...

BACKGROUND AND OBJECTIVE Cryogen sprays are used for cooling human skin during various laser treatments. Since characteristics of such sprays have not been completely understood, the optimal atomizing nozzle design and operating conditions for cooling human skin remain to be determined. MATERIALS AND METHODS Two commercial cryogenic spray nozzles are characterized by imaging the sprays and th...

In this study, we numerically examine thrust performance of the linear aerospike nozzle micro-thruster for various nozzle spike lengths and flow parameters in order to identify optimal geometry(s) and operating conditions. Decomposed hydrogen-peroxide is used as the monopropellant in the studies. Performance is characterized for different flow rates (Reynolds numbers) and aerospike lengths, and...

Numerical simulations have been performed for assessment of compressibility correction of two-equation turbulence models suitable for large scale separation flows perturbed by pintle strokes. In order to take into account pintle movement, a sliding mesh method was applied. The chamber pressure, mass flow rate, and thrust have been analyzed, and the response lag and sensitivity at the chamber an...