NASA SBIR 2005 Solicitation


SUBTOPIC TITLE:Cryo & Thermal Management
PROPOSAL TITLE:A New Wick Structure to Significantly Improve Heat Pipe Performance

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Mainstream Engineering Corporation
200 Yellow Pl
Rockledge ,FL 32955 - 5327
(321) 631 - 3550

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Robert P Scaringe
200 Yellow Place
Rockledge, FL  32955 -5327
(321) 631 - 3550

Increasing thermal requirements for space-based thermal control systems are straining the capabilities of conventional heat pipes. Mainstream has experimentally demonstrated a new wick configuration that has been shown to more than triple the heat transport capacity of an otherwise identical copper water heat pipe(this proposal contains the experimental data). This Phase I will seek to extend these heat pipe experiments. Improved heat pipe technology is relevant and important to meeting thermal technology needs; it is well known that any means to improve heat pipe capacity widens the potential applications for their use. Extending the capability of a simple, highly reliable passive system means more applications where this passive heat pipe approach can be used instead of the more complex, and potentially less-reliable, active systems.

This Phase I includes heat pipe experiments and limited performance optimization. Mainstream has already performed the marketing and commercialization studies, and we have secured a commercial aerospace partner (with funding) for a follow-on commercialization effort. Phase III commercialization would parallel our other SBIR commercialization efforts. Mainstream's prior record of accomplishment has demonstrated that we are very serious about commercialization and our DoD commercialization index is 90%.

The proposed improvement to conventional heat pipe wick structures would be useful wherever heat pipes are currently used and increased heat flux capability would be desirable; i.e., thermal control systems of small satellites with variable duty cycles, spacecraft radiators, high-power electronic cooling, and avionics cooling. Also, when thermal control systems are needed at temperatures above the optimum for an Ammonia Heat Pipe (above about 30?C) and below the optimum for a Water Heat Pipe (about 150?C), the current heat pipe working fluids that can be used have very low liquid transport factors. Methanol--about the best working fluid in this range--has a heat transport factor that is at least half that of ammonia, and even less when compared to water. Since this is an area where considerable electronics cooling could be operating, the use of a higher heat transport configuration could improve the performance of these alternative working fluids as well as extending the operating range of water and ammonia working fluids; this would have a tremendous effect on future cooling system designs. Improved heat pipe wick technology represents a major advancement in the technology and would have far-reaching applications in both manned and unmanned NASA applications.

Heat pipes are not in general a low cost solution to the cooling problem, but they are very reliable and effective and they have tremendous potential as power levels and volume requirements of commercial electronics increase. Until recently, heat pipes have been used mainly in difficult thermal control applications, such as: aircraft electronics, traction drives, portable computers, audio amplifiers and cooling of closed cabinets operating in harsh environments. The most versatile feature of using heat pipes is the wide variety of geometries that can be constructed to take advantage of the available space around the electronics to be cooled. In many applications, the available heat sink volume above the electronics is limited by the board-to-board spacing. In these situations, heat pipes are used in a low profile design that transports the heat to a large fin stack. For such near-term applications, this proposal contains market research data that demonstrates a significant market potential for improved heat pipe technology.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.


Form Printed on 09-19-05 13:12