Techniques for Surface Wetting of NaK to Copper for Liquid Metal Slipring Homopolar Machines.
Abstract
High current density homopolar machines employing liquid metal sliprings require wetted surfaces to minimize power losses induced by contact resistance and to maximize fluid retention during machine operation. A literature review and evaluation were performed to determine which methods of establishing wetting of NaK to copper might be applicable to new naval propulsion machines. Requirements for these methods include that they be performed shipboard, in-situ, repeatably, at low temperatures, and with the least disruption to presently planned systems. Methods of measuring and establishing liquid metal wetting, as well as the theories of wetting, were reviewed. Several new approaches for establishing and maintaining wetting, within the naval machine constraints, were discovered. Two promising techniques recommended for development include small lithium additions to NaK and ultrasonic encouragement. Small scale cursory tests were positive for both techniques. A detailed experimental test plan, to fully develop and characterize these and other applicable wetting techniques, is presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1976
- Accession Number
- ADA031861
Entities
People
- F. G. Arcella
- R. E. Witkowski