This paper presents the experimental results the choked flow characteristics of a subcritical refrigerant through a converging-diverging nozzle. A test nozzle with a throat diameter of 2 mm was designed and developed. The influence of operating conditions on the choked flow characteristics, i.e., the pressure profile and mass flow rate under choked flow conditions are investigated. The results ...

High-efficiency rock breaking by hydraulic jetting is the key to radial horizontal drilling technology. In order improve efficiency of jet in wells, based on LS-Dyna display dynamics, a numerical simulation model single-nozzle was established analyze influence different nozzle parameters rock-breaking effect. Then, spin multi-nozzle bit established, and rotation speeds effect analyzed. Finally,...

Results are presented for physical experiments that illustrate the possibilities and efficiency of visualization for studying the effect of operating conditions (backward-facing stepped forming nozzle, exit diameter of anode, mass flow, and composition of working gas) on plasma flows at low Reynolds numbers for advanced coating and powder processing. In particular, the shadow method, based on a...

A centrifugally driven pulse-free flow has been used for generation of tripolyphosphate (TPP)-gelated chitosan beads with tunable diameters ranging from 148 to 257 μm. The production process requires a single motor as the sole actively actuated component. The 2 % (w/w) chitosan solution was extruded through a polymeric nozzle with an inner diameter of 127 μm in the centrifugal field ranging fro...

The current work discusses our efforts to fabricate 3-D micro-nozzles using a novel, modified MEMS-LIGA process. These nozzles may provide a spray pattern to continue to reduce spray droplet sizes while minimizing interspray drop collisions and optimize the entrainment of air among the array of liquid spray streams. The paper also discusses the efforts made to form a bond between the micro-nozz...

Optimization of a High-Efficiency Jet Ejector by Computational Fluid Dynamics Software. (May 2005) Somsak Watanawanavet, B.S., Chulalongkorn University Co-Chairs of Advisory Committee: Dr. Mark T. Holtzapple Dr. Charles J. Glover Research was performed to optimize high-efficiency jet ejector geometry (Holtzapple, 2001) by varying nozzle diameter ratios from 0.03 to 0.21, and motive velocities f...

A centrifugally driven pulse-free flow has been used for generation of tripolyphosphate (TPP)-gelated chitosan beads with tunable diameters ranging from 148 to 257 microm. The production process requires a single motor as the sole actively actuated component. The 2% (w/w) chitosan solution was extruded through a polymeric nozzle with an inner diameter of 127 microm in the centrifugal field rang...

The dispensing of tiny droplets is a basic and crucial process in a myriad of applications, such as DNA/protein microarray, cell cultures, chemical synthesis of microparticles, and digital microfluidics. This work systematically demonstrates droplet dispensing into immiscible fluids through electric charge concentration (ECC) method. It exhibits three main modes (i.e., attaching, uniform, and b...

Boiling jet impingement heat transfer from a simulated electronic chip to Fluorinert FC-72 within a clamshell avionic module was investigated for dependence upon inlet fluid temperature, nozzle diameter, nozzle to chip spacing, jet velocity, and chip length. The clamshell module was designed and fabricated to accommodate both single and multiple chip boards and to demonstrate the feasibility of...

Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by particle size reduction. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF. Carbon dioxide (CO2) with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in supercritical CO2 with cosolvent acetone was measured using a dynamic app...