Demonstration of a Self-Contained Organic Rankine Silent Engine

This paper summarizes an internally funded program to develop a self-contained externally fired Rankine cycle power system capable of silent operation in a tactical combat environment. System working fluid considerations, including ultimate application requirements, materials compatibility, thermal stability, lubricating properties, and thermodynamic characteristics, led to the selection of monoisopropylbiphenyl primarily because of its low melting temperature. Over 400 hr of testing, conducted on this self-contained system to assess the noise and performance characteristics under a range of ambient conditions, are reported. These test results establish the basis for applying this concept of dynamic power generation to a relatively wide range of future military requirements.