Engineering topics

Eugene H Trinh

Publications and source records attributed to Eugene H Trinh.

2 records

NASA NTRS1989

Acoustic convective system

A small and simple system is provided for cooling or heating a small component by flowing air or other fluid over it, which does not require any macroscopic moving parts. The system includes a transducer and reflector that are spaced apart with the component between them, and with the transducer being operated at a frequency resonant to the spacing between it and the reflector. The resulting standing wave pattern produces acoustic streaming which results in the circulating of air or other fluid in the environment across the component. The system is especially useful in the reduced gravity environment of outer space because of the absence of any buoyancy-induced convection there.

Eugene H Trinh↗

NASA NTRS1988

Controlled sample orientation and rotation in an acoustic levitator

A system is described for use with acoustic levitators, which can prevent rotation of a levitated object or control its orientation and/or rotation. The acoustic field is made nonsymmetrical about the axis of the levitator, to produce an orienting torque that resists sample rotation. In one system, a perturbating reflector is located on one side of the axis of the levitator, at a location near the levitated object. In another system, the main reflector surface towards which incoming acoustic waves are directed is nonsymmetrically curved about the axis of the levitator. The levitated object can be reoriented or rotated in a controlled manner by repositioning the reflector producing the nonsymmetry.

Martin B Barmatz↗