20 -- Homopolar Brush Workshop Announcement

11/23/2004 Homopolar Brush Workshop Announcement Background: The U.S. Office of Naval Research (Department of the Navy) is sponsoring development of homopolar motors for navy ship propulsion applications. Current collectors (brushes) are a key technology essential to success of this development. ONR is interested in obtaining input from the US science and technology community in the interest of furthering understanding of this essential technology. Announcement: ONR is hosting a workshop for the purpose of identifying new, innovative, and dynamic science and technology approaches in current collection for large superconducting homopolar motors. We are seeking to discover and develop technologies that will lead to current collectors capable of operating at the following full-scale homopolar motor conditions: - Brush Current Density: >188 A/cm^2 - Brush Current: >375 A/brush (DC)Created on 11/8/2004 9:45 AM - Total loss per brush < 30 watts/brush (goal), <60 W/brush (max.) - Slipring coverage: 75% - Brush aspect ratio: 4 to 1 (circumferential to width dimensions at the slipring interface) - Life: 15 years in navy combatant application, implying a dimensionless wear of 3x10^-11 (wear/distance traveled on slipring) - Operation in a minimum magnetic field of .42 Tesla perpendicular to brush/slipring interface surface and .79 Tesla parallel to brush interface surface and perpendicular to the direction of rotation any direction. Goal is operation in fields of 1.4T and .8 T respectively. - Brush sliding speed: 0 to +/-15 m/sec. - Brushes are Non-commutating riding on a slipring interface Liquid metal current collectors are specifically excluded for this forum. Funding opportunities are likely to arise as a result of white papers and proposals submitted in response to the recommendations from this workshop. ONR Broad Agency Announcement (BAA 04-001) will be applicable to this program and is available on the ONR website. This technology is export controlled, thus workshop attendance will be restricted to U.S. citizens only. All information presented and discussed in this workshop will be non-proprietary. Discussion: The Homopolar motor brush workshop is designed to inform the community of the ongoing program and technical issues, and to accept feedback from the community on directions for long term research in brush development. The workshop will begin with the first day including a description of the ONR homopolar motor development program and specifically the brush development efforts, modeling and results to date. The presentations will be followed on the second day by targeted panel sessions that will discuss, develop and recommend the science and technology needs to which the technical community can respond. Each panel will brief their conclusions to the group at large atthe end of the second day. A tentative agenda is given below. The three discussion areas planned for the panel sessions are: I. Macroscopic brush and brush holder issues II. Microscopic phenomena and issues related to conduction, wear and loss mechanisms III. Modeling and simulation of brush static and dynamic behavior under operating conditions, and of the motor itself which defines the brush operating environment. Invitation: The Office of Naval Research invites all interested parties to register and participate in this exploratory workshop to be held at General Atomics Corp. facilities in LaJolla California on December 16 and 17, 2004. Tentative Agenda: Day 1, 0800 - 1700: - Welcome remarks: General Atomics - Workshop expectations: Steve Schreppler, ONR - Homopolar Motor and Brush Development Overview - Brush modeling efforts and results - Macroscopic brush and holder physics/phenomena - Microscopic phenomena at the rubbing interface - Expectations for day 2 and panel assignments - Tour GA facilities for homopolar motor development and brush development Day 2, 0800 - 1700 - Instructions to panels - Panel discussion - Prepare panel briefing - Panel brief-outs - Closing remarks, Steve Schreppler, ONR Registration: - To register for this workshop, please e mail Susan Duncan at (contact@example.gov), +1 (555) 000-0000 X104 or Victoria Toth at (contact@example.gov), +1 (555) 000-0000 X141 with the following information o Name o Affiliation o Address, e mail and phone number o Which of the three discussion areas above are of most interest to you - Deadline for registration is December 1, 2004. - Alternate point of contact is: Roy Dunnington, Anteon Corp. (contact@example.gov), +1 (555) 000-0000 X122 - A nominal fee may be charged to defray refreshments and lunch costs. Accommodations and Directions: See General Atomics website at http://www.ga.com/map/index.html. Attendees will be responsible for making their own travel and accommodation arrangements.