The goal of this research project was to further the development of an electromechanically controlled variable-orifice nozzle by creating an electronic control system and then evaluating that system based on step and ramp inputs. The control system was developed in a programming environment that combined an electronic data acquisition system and actuator with pressure and flow sensors. A propor...

Micro Piezo technology is offering superior features in ink ejection performance, compatibility with a wide variety of inks, and durability. As a result, this technology has already being utilized effectively in various commercial and industrial fields such as photo lab printing, digital printing, textile printing, and color filter manufacturing. However, new printheads that have a larger numbe...

Inadequate hole cleaning can lead to many problems in horizontal and directional wells. In this work, we tried to investigate the cutting transport phenomenon by an experimental directional drilling simulator, considering the differences between the operational and experimental conditions. The inclination, fluid type (water, foam, viscous, and dense), rotary speed (0 and 110 rpm), nozzle bit si...

Use of jet cavitation, however, occurs through an exit nozzle whose diameter can be changed, thereby changing volume with changing velocity. The results of such a change is shown to tie cavitation damage more powerfully to volume flow than to velocity. A specific example is in cavitation erosion of a high strength igneous rock which remained virtually undamaged at 70 MPa driving pressure but wa...

Current-free double layers can develop in a collisionless, inertia-controlled plasma with two electron populations, expanding in a convergent-divergent nozzle. The double layer characteristics depend on whether they develop at the nozzle divergent side, convergent side, or throat. The divergent-geometry double layer describes faithfully the Hairapetian-Stenzel experiment [Phys. Rev. Lett. 65, 1...

Planar laser-induced fluorescence visualisation isused to investigate nonuniformities in the flow of a hyper-sonic conical nozzle. Possible causes for the nonuniformityare outlined and investigated, and the problem is shown to bedue to a small step at the nozzle throat. Entrainment of coldboundary layer gas is postulated as the cause of the signalnonuniformity.

Flight tests recently completed at the NASA Dryden Flight Research Center evaluated performance of a hydromechanically vectored axisymmetric nozzle onboard the F-15 ACTIVE. A flight-test technique whereby strain gages installed onto engine mounts provided for the direct measurement of thrust and vector forces has proven to be extremely valuable. Flow turning and thrust efficiency, as well as no...

1) Hydraulic Analysis of the Emergency Core Spray System in a BWR The emergency spray system of a BWR delivers cold water to the core after a large-break loss of coolant accident has emptied the reactor vessel. The system comprises a large water pool, a pump, a spray nozzle and connecting pipes (Figure 1). All pipes are smooth round tubes made of stainless steel with 10 cm internal diameter. Th...

Utilizing experimental techniques of Nano-particle based Planar Laser Scattering (NPLS) and schlieren photography, the flow patterns and mixing characteristics of a designed HYLTE (HYpersonic Low TEmperature) nozzle were investigated in this paper. In order to visualize the non-reacting flowfield of supersonic angled jets into a supersonic crossflow in the HYLTE nozzle, a testing section with w...