Engineering topics

Leung, E. W.

Publications and source records attributed to Leung, E. W..

4 records

NASA NTRS1991

Rotation of ultrasonically levitated glycerol drops

Ultrasonic levitation is used to suspend single millimeter-size glycerol drops in a rectangular chamber. Audio-frequency laterally standing waves set up in the chamber are used to torque the suspended drops. The shape evolution of the drop under the combined effect of centrifugal forces and the acoustic radiation stress, along with its angular velocity are monitored, using video imaging and light scattering techniques. The results show good qualitative agreement with the theoretically predicted shape evolution as a function of angular velocity.

Biswas, A.↗

NASA NTRS1985

Force on a heated sphere in a horizontal plane acoustic standing wave field

The force on a heated sphere in a horizontal plane acoustic standing wave field is the subject of this investigation. The heated sphere produces a thermal gradient in the resonance chamber. The force on the sphere in a direction perpendicular to that of gravity is measured. This force is enhanced in the region near the pressure node, and is weakened in the region near the pressure antinode. Measurements of the force on a heated sphere with sound pressure levels between 148 and 156 dB are presented.

Leung, E. W.↗

NASA NTRS1985

Acoustic Position Servosystem

Servosystem automatically centers levitated objects within given volume.

Leung, E. W.↗

NASA NTRS1985

Acoustic Sorter for Small Parts

Sorting system uses acoustic reasonance chamber, detects, and rejects anomalous parts on automated assembly line. System particularly suited to small nuts, bolts, pins, and assemblies which previously required expensive three dimensional television-monitoring systems to prevent misfeeds.

Wang, T. G.↗