Towards a Hybrid Mechanically-Pumped Loop Heat Pipe: Investigation of Bearingless Micro Pumps
Abstract
As the electronics systems aboard air and spacecraft grow in scale and complexity, so too does the heat generated by those systems. A high heat flux, compact, maintenance-free cooling system is required to meet the increased demand for heat removal. Loop heat pipes are robust and effective thermal management systems that are long-life and maintenance-free, making them ideal for use in unmanned spacecraft. Integrating a mechanical pump into a loop heat pipe system can drastically improve the systems heat removal capacity through increased mass flowrate. Like loop heat pipes, magnetically-driven bearingless pumps are also maintenance-free, which is a necessity in the space environment. This work details the modeling of a low-flowrate, magnetically-driven bearingless centrifugal pump and a computational fluid dynamics study of the pumps operation and performance under a range of conditions that are typical to the demands of a satellite thermal management system. The purpose of this computational study is to investigate the failure mechanism of a bench-test unit that was unable to generate a pressure head with its intended working fluid of ammonia. Model development, validation, and pump performance with multiple working fluids are discussed. The cause of the pumps failure is investigated. Following the failure mode investigation, an alternative pump design was identified and several units acquired and tested with a variety of working fluids, including ammonia. These results and plans for integration in a hybrid loop heat pipe are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 04, 2018
- Accession Number
- AD1060028
Entities
People
- Evan W Hyde
- Gabriel B. Goodwin
- Jesse R. Maxwell
Organizations
- United States Naval Research Laboratory