Stirling Innovations LLC Technology Legacy and Resources Continued
In 1967, the DWDL group within McDonnell Douglas was awarded a contract with the National Heart, Lung, and Blood Institute to develop a fully implantable radioisotope fueled artificial heart FPS power source. While also conducting several other FPS development contracts, the artificial heart program became the primary funding source of the DWDL Stirling group for 25 years as it transitioned to the University of Washington (UW) and Stirling Technology Co. (STC). Many innovations, including flexure bearings integrated with clearance seals and phase-change salt TES integrated with FPS engines, emanated from the artificial heart program. STC was eventually renamed Infinia and went on to conduct numerous FPS and phase-change salt TES prototype development government contracts as well as to raise extensive capital for commercial solar dish engine development. The commercial effort installed over a hundred dish engine systems in fields of one to 35 units as the system iterated through four engine generations. This culminated in the installation of 429 3.5-kW dish systems as a 1.5-MW green power plant at the Tooele Army Depot in 2013. While the solar development was a technical success, and closely approached initial cost and performance goals, the much more rapid decline in PV prices than anticipated during the development period led to a non-competitive product and resulted in Infinia bankruptcy in 2013. An Israeli company Qnergy acquired the Infinia assets, including the production facility in Ogden, UT, and very successfully adapted the solar engines to serve the remote power market. An Infinia R&D and cryocooler group that remained in the Richland, WA area when the Board of Directors moved Infinia to Ogden, UT developed uniquely suitable cryocoolers that integrated with an AMSC high temperature superconductor (HTS) degaussing system for Navy ships. In 2017 AMSC acquired that group from Qnergy and continues to produce the Navy cryocoolers in Richland, WA. Mr. White left AMSC in 2021 to found SI. Infinia, Qnergy and AMSC have been very successful in their respective application of FPS systems.
Contribution to Stirling Machine World on Ted Finkelstein Continued
I first met Ted in late 1962 when he joined Atomics International (AI). Ted had been hired by Bob Carter to pursue the goal of a free-piston Stirling engine for radioisotope space power systems. Bob, an unheralded visionary in his own right, had hired me a few months earlier to assist Ted when he arrived. At first, Bob had me evaluate a pet idea of his about harnessing acoustic energy he had observed from heated tubes - the germ of a concept that later became thermoacoustic engines in a totally independent development. I spent only a few weeks on that before Bob left for a teaching position at the University of Missouri, and I was given an interim assignment while waiting for Ted's delayed arrival. Ted had been working on kinematic engines at Battelle Columbus, but Bob hired him to pursue the free-piston concept Ted had identified when he was approached by Bob to consider starting a Stirling project at AI.
Ted and I spent a little over a year analyzing free-piston engine dynamics and thermodynamics and designing a feasibility demonstration engine on an internal R&D (IRAD) project funded by AI. We built very crude models of an engine that demonstrated conversion of heat to mechanical work but did not achieve self-sustained operation, and of a mechanically driven linear alternator. Before those were fully functional, a routine IRAD review process with parent company North American Aviation (NAA) exposed the project to a NAA Vice President. His response was that a group he had managed at Sundstrand had unsuccessfully attempted to design a linear alternator, and it was obvious to him that if those guys couldn't make it work the objective was impossible. The project was canceled on the spot! I spent the next couple of years working on an MHD program, while Ted spent a few months at sister division Rocketdyne getting frustrated, so he quit to very successfully pursue other means of financial survival while always focusing all the effort he could on his own Stirling ideas, interspersed with occasional very selective consulting activities.
With that background, the wide-ranging connections and indirect fallout from Ted's efforts, little or none of which would have occurred if Ted had never found his lifelong love of Stirling, should be a bit more understandable. While working at AI, Ted shared some of his ideas with William Beale, planting the seeds of what eventually blossomed into the first fully operational FPSE, and ultimately the existence of Sunpower and everything it has become. A colleague working on thermionic conversion technology at AI while Ted and I were doing the Stirling project there became enamored at that time with the FPS concept. In 1966, he got the opportunity to initiate a FPSE project with Douglas Aircraft (later McDonnell Douglas Corporation -MDC) at the embryonic Donald W. Douglas Laboratories (DWDL) in Richland Washington. That was none other than Bill Martini, who later achieved iconic status within the Stirling community in his own right. Bill began building his team at DWDL by hiring me away from Al. The goal of this relatively well funded IRAD project was to develop FPS technology to the point where it could attract government funding for space radioisotope and terrestrial military power systems. In one of those ironies of life, that effort achieved no more than a couple of small study contracts with the Army, but in 1967 DWDL won a contract with the National Institutes of Health (NIH) for a radioisotope-fueled fully-implantable artificial heart power source.
That contract supported a team of 8-10 people for more than 25 years - at DWDL for 10 years until that facility was closed and the contract transferred to the University of Washington (UW) at a branch campus in Richland for another 10 years - and continuing on after the UW artificial heart group spun out in a technology transfer program to form Stirling Technology Company (subsequently renamed Infinia Corporation). Throughout most of the heart contract period, Ted was active via NIH in a peer review capacity on this and other Stirling heart projects they funded.
There are other first and second order consequential results of Ted's influence. The energy systems group at AI was subsequently absorbed by Rocketdyne, where the fallout from the early work there included promoting Stirling for the SP-100 in the 80's and participation in the Stirling Radioisotope Generator space program before and after the turn of the century. In addition to the existence of Infinia, there are other indirect but very significant fallouts from the Stirling work at DWDL. It inspired another group within MDC to engage United Stirling of Sweden, subsequently Kockums, to initiate the 25-kW dish engine program that included developing the MDC dish and beginning the licensing agreement that today is continued by Stirling Energy Systems. During the artificial heart years at DWDL, an IRAD effort was initiated to develop a 500-W demonstration system to help attract further governmental development funding. It soon became apparent that the magnitude of effort required exceeded the resources available. As a result of searching for a team to take on the linear alternator effort, a Mechanical Technology Inc. (MTI) group under Pete Curwen stepped up to the plate. A joint agreement was reached wherein DWDL would develop and have rights to the engine and MTI would develop and have rights to the linear alternator. DWDL built the engine and MTI the alternator, but before the two could be integrated MDC made extensive cutbacks in IRAD efforts in response to an aerospace downturn that included stopping the DWDL project. This triggered a DWDL/MTI agreement clause that enabled MTI to complete the full demonstration system on its own. As they say, the rest is history.
Ted had other notable accomplishments that include many individual publications of original work, the balanced compounding concept, and working with Allan Organ to write "Thermodynamics and Gas Dynamics of the Stirling Cycle Machine" and "Air Engines: The History, Science, and Reality of the Perfect Engine". He partnered with the late Stig Carlquist to form TransComputer Associates. Others can speak to those areas better than me, but my goal here was to share some less well known perspectives on Ted's career.