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Full-Text Articles in Engineering

Passive Phase Separation Of Microgravity Bubbly Flows Using Conduit Geometry, Ryan M. Jenson, Andrew Paul Wollman, Mark M. Weislogel, Lauren Sharp, Robert Green, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer Oct 2014

Passive Phase Separation Of Microgravity Bubbly Flows Using Conduit Geometry, Ryan M. Jenson, Andrew Paul Wollman, Mark M. Weislogel, Lauren Sharp, Robert Green, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer

Mechanical and Materials Engineering Faculty Publications and Presentations

The ability to separate liquid and gas phases in the absence of a gravitational acceleration has proven a challenge to engineers since the inception of space exploration. Due to our singular experience with terrestrial systems, artificial body forces are often imparted in multiphase fluid systems aboard spacecraft to reproduce the buoyancy effect. This approach tends to be inefficient, adding complexity, resources, and failure modes. Ever present in multiphase phenomena, the forces of surface tension can be exploited to aid passive phase separations where performance characteristics are determined solely by geometric design and system wettability. Said systems may be readily designed …


Pressure Impulses During Microsecond Laser Ablation, Hanqun Shangguan, Lee W. Casperson, Scott A. Prahl Dec 1997

Pressure Impulses During Microsecond Laser Ablation, Hanqun Shangguan, Lee W. Casperson, Scott A. Prahl

Electrical and Computer Engineering Faculty Publications and Presentations

The collapse of laser-induced cavitation bubbles creates acoustic transients within the surrounding medium and also pressure impulses to the ablation target and light-delivery fiber during microsecond laser ablation. The impulses are investigated here with time-resolved flash photography, and they are found to occur whether or not the light-delivery fiber is in contact with the target. We demonstrate that the impulses depend primarily on the energy stored in the cavitation bubble. They are not directly dependent on the mode of light delivery (contact versus noncontact), and they are also not directly correlated to the other acoustic transients. The pressure impulses do …