Performance and flow characteristics of a conical microthruster operated in cold thruster mode are presented. Nitrogen, Argon and Carbon dioxide were used as the medium. The performance parameters (specific impulse, impulse efficiency, thrust coefficient and characteristic velocity) are measured. The chamber pressure was varied from 2.8 bar to 12 bar. It is found that the high viscous loss severely degrades the performance of the thruster at a pressure below 5 bar. However, the mass flow remains unaffected even at a low pressure. The computed Mach number shows that at low pressures flow separates earlier. The schlieren photographs show the flow development inside the thruster at different pressures. Interestingly, a highly asymmetric flow field exists in the nozzle expansion section. Row perturbation effects cause the flow to separate from the upper wall and to remain attached with lower wall.

The use of Gas-Liquid Cylindrical Cyclone (GLCC © ) separators for gas-liquid separation is a new technology for oil and gas industry. Consequently, it is important to understand the flow behavior in the GLCC © and effect of different geometrical configurations to enhance separation. The main objective of this study is to address the effect of different inlet configurations on flow behavior in the GLCC © by measuring velocity components and turbulent kinetic energy inside the GLCC © using a Laser Doppler Velocimeter (LDV). Three different inlet configurations are constructed, namely: one inclined inlet, two inclined inlets and a gradually reduced inlet nozzle. Axial and tangential velocities and turbulent intensities across the GLCC © diameter were measured at 24 different axial locations (12.5” to 35.4” below the inlet) for each inlet configuration. Flow rates of 72 and 10 gpm are selected to investigate the effect of flowrate (Reynolds number) on the flow behavior. Measurements are used to create color contour plots of axial and tangential velocity and turbulent kinetic energy. Color contour maps revealed details of the flow behavior.

The stability behaviour of jet diffusion flames in a co-flowing stream of air was examined. Their lift-off, reattachment and blowout limits were established for methane, propane, ethylene and hydrogen. The co-flowing air stream velocity affected significantly the mechanism of flame stabilization. Different flow regimes where the blowout of lifted flames or attached flames can occur were recognized. A transition region in which both the blowout of lifted flames as well as that of attached flames was observed and identified with respect to the value of the air stream velocity. It was found that the blowout limits for lifted flames in this region were much smaller than for the attached flames. The effects of changes in the nozzle geometry and co-flowing stream composition were also considered.