Cryogenic Liquid Operational Seal Enhanced Rotary Union

In Phase I Physical Optics Corporation (POC) has developed and demonstrated the feasibility of a Cryogenic Liquid Operational Seal Enhanced Rotary (CLOSER) union system to address the Navy"s need for a robust coolant gas rotary union design. The CLOSER union system has been designed to provide flow capability (up to 10 g/s), rotary speed capability (up to 3600 rpm), high operational coolant pressure (300 psig maximum), durability, long life (>12,000 hr between overhauls), and high reliability (>3,000 hr MTBF) required by air-cooled naval power systems. CLOSER is designed to operate with no coolant leakage and eliminates the need to replenish lubricants and replace contact seals, which are otherwise subject to friction-based wear and tear, by utilizing a passively temperature-controlled array of frictionless ferrofluidic seals. The goal of the Phase II effort is to manufacture a CLOSER union prototype that successfully demonstrates the required capabilities necessary for integration, provides significant performance and cost benefits as compared to current systems, and exhibits effectiveness and suitability for PMS320. This system will be validated against NAVSEA requirements for cryogenic application, conformance to MIL-S-901D (shock and vibration) testing, and scalability to support high-temperature superconducting (HTS) generators with power output from 100 kW to 40 MW.