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TvU Past Research Projects

Listed from newest to oldest.


A single fiber endoscope is being developed that can be perform high temperature thermal imaging in a jet engine turbine and combustor. Surface temperature maps of an operating turbine blade is the ultimate objective of jet engine research efforts. Initial feasibility work centered on experimental demonstration that the fiber could accurately detect temperatures on the order of 1000°C; the optical response of samples relevant to the turbine environment was tested at temperatures up to 1200°C. Equipment needs for a prototype instrument were documented in detail and system characteristics such as spatial and temporal resolution were estimated based on experimental testing. Continued development and funding relied on techniques for multimode single fiber imaging published in Physical Review Letters. A prototype imaging system was designed for fabrication in a follow-on NASA program that was subsequently awarded. Progress on the prototype instrument was delayed when work to duplicate the Physical Review Letters research demonstrated that it was fraudulent. An alternate fiber image calibration technique is being developed. When complete, further funding for the prototype instrument will be sought.

NASA SBIR Contracts: # NNX14CL26P, 20 June, 2014 through 19 December, 2014; Contract # NNX15CC08C, 26 May, 2015 to 10 April, 2017.

Status: Proceeding at TvU with IR&D funding with the goal of the image calibration of a single sapphire fiber.


This program demonstrated the feasibility of large ceramic to metal joints/seals that can tolerate extreme environments. The immediate application of the work is bonded sapphire viewports for a Venus probe. TvU's commercial viewport products had demonstrated that the pressure and temperature constraints of the surface of Venus would be met, while the use of materials appropriate to the atmospheric conditions would satisfy the overall physical constraints. The ceramic bonding and viewport systems were shown to be adaptable to overall NASA use constraints. Work detailed the design of the ceramic to metal joining process as well as a generic viewport design. A variety of oxide ceramic fixtures were fabricated and tested under a wide range of thermal and mechanical conditions. A specific prototype viewport was designed, fabricated, and tested at Venus lander atmospheric conditions. Initial delayed testing in Venus surface conditions at NASA resulted in viewport failure after 90 minutes. A follow-on program was initiated that resulted in successful demonstration of the sealed viewport for long periods. Testing established that the seal had an extremely low leak rate; further testing is required to determine if the leak rate meets NASA specifications.

NASA SBIR Contracts: # NNX10CD80P, 29 January, 2010 through 29 July, 2010; Contract # NNX14CG16P, 20 June, 2014 through 19 December, 2014.

Status: Commercial product offered.


This program proposed to develop a dispersed-particle gas absorber (PGA) to collect CO2 from industrial and power generating combustion exhausts. Large numbers of evenly spaced, small particles falling through the exhaust gas stream are used to efficiently absorb and remove the CO2 from the gas. The particles absorb and store the CO2 in the particles in a water-soluble form that can be removed from the particles so that they can be reused in a continuous process. The particles are sized to fall at the proper speed to give an appropriate residence time, and the particle field is sized to absorb most of the CO2 in the warm gas. An important aspect of the project was the use of absorbing enzyme particles that could tolerate exhaust temperatures. These particles were proposed by the Professor Kumar of the University of Connecticut (UCONN). UCONN was not able to produce the needed particles required for testing. However, extensive spray CO2 absorption experiments were performed at TvU using standard methylamine liquid. Extremely high CO2 absorption was demonstrated in the liquid boundary layers on the chamber walls contrary to prediction and apparent industry experience. Lack of particles ended project work.

NSF Grant # IIP-0740346, $100,000, January 1, 2008 to July 31, 2008.

Status: Particles abandoned, but wall layer absorption seems attractive. Further work and funding improbable.


This program proposed to develop an acoustically enhanced Droplet Heat Exchanger (DHX). DHXs have high contact area, no interface losses, low pressure drop, and superior heat transfer characteristics. Adding high intensity sound to the DHX design causes the local gas motion generated by the sound to greatly enhance the droplet heat transfer, and the sound causes any small droplets to be agglomerated into larger droplets. Acoustic enhancement of a DHX allows standard spray injectors to be used, making fabrication and installation inexpensive and simple. Resonant high intensity acoustical excitation provides a low-power means for providing a reduced-size, practical droplet heat exchanger. Efficient sound insulation eliminates external sound from the acoustically enhanced DHX. Many other applications are also possible, including droplet/particle reactors, humidifiers, and gas scrubbers. The program was unable to experimentally demonstrate the necessary acoustic levels, apparently due to lack of experience rather than a fundamental problem.

NSF Grant # OII-0610518, $100,000, July 1, 2006 to Dec. 31, 2006.

Status: Concept appears valid but will not be pursued due to the difficulty of demonstrating the needed sound levels and the probable impracticality of industrial application without previous clear and major diffusion enhancement.


This is a program to develop a high efficiency solar furnace core that greatly lessens the heat losses from the furnace core, either greatly reducing the amount of solar radiation needed to reach a specified temperature, or greatly increasing the temperature it can achieve. Specific program goals include: 1) specification of the techniques to be used for generating the appropriate vacuum in the furnace and the vacuum level that must be achieved to provide insulation from gas convection; 2) improved heat and solar radiation shields; 3) improved crucible technology; and 4) very high temperatures (2500°C). Vacuum conditions were established and a basic design generated that appeared to satisfy the constraints for a high efficiency solar furnace core.

NASA Marshall Space Flight Center Contract # NNM05AA41C, $70,000, Jan. 21, 2005 to July 25, 2005.

Status: Insufficient interest in NASA at the time for work to continue. Probable application as an extra terrestrial furnace may be pursued.


The design of a rugged, reliable, compact, standardized imaging system for hypervelocity and re-entry vehicles was developed. It uses sapphire windows, small imagers, and independent telemetry. This system can tolerate the severe aerothermal environment associated with hypervelocity flight. The proposed system answers a critical need for enhanced situational awareness, performance analysis, and rapid anomaly resolution. Images of control surfaces, vehicle health, separation deployment, plume dynamics, combustion behavior, and many other vehicle properties provide a rapid, global assessment of the flows and control status of aerospace vehicles and propulsion systems using a standardized diagnostic package. The system design includes a window, window mounting system, camera, and independent telemetry system. Work included computational aerothermal modeling, window, mount, camera, and telemetry design, preliminary hazards analysis, and feasibility/applications assessment. The imaging system would have broad application for NASA, DOD, and commercial aerospace vehicles.

NASA Langley Research Center P.O. # NNL04AB18P, $70,000, Jan. 16, 2004 to July 15, 2004.

Status: Work ended with the cancellation by NASA of the X43 program where this system was to be applied. No further work planned.


A full prototype next-generation semi-flush flasher system was developed for airport runway approach lighting. Systems at the time were many years old and inefficient. Airports need inset flashers to add runway length and more efficiently use strictly limited land allocations. An new inset flasher design was optimized both optically and electrically. Phase 1 program feasibility was demonstrated by comparing prototype performance with FAA specifications and current systems and by assessing the practicality and value of the other program innovations. A flasher fixture based on a Phase 1 prototype was optimized, fabricated, and tested, forming a Phase 2 prototype to be commercialized. Thoughtventions Unlimited LLC, specializing and research and development, and Flight Light, Inc., a manufacturer of airport lighting systems, teamed to bring state of the art optics and commercial practice to the program. A flasher fixture based on a Phase 1 prototype was optimized, fabricated, and tested, forming a Phase 2 prototype to be commercialized.

DOT/FAA Contract # DTRS57-00-C-10008, "An Optimized Semi-Flush Flasher," $100,000, Dec. 8, 1999 to November 1, 2000. DOT/FAA Contract # DTRS57-01-C-10032, "An Optimized Semi-Flush Flasher," $750,000, Apr. 6, 2001 to April 5, 2004. Contract Mod/addition Feb 03 add 60k$ end 23 Jun 2004.

Status: Program was successfully completed and a prototype delivered to the FAA for testing and evaluation. No further work was performed because the program was only performed by the FAA to force the major commercial companies to create an equivalent product, which they did and was purchased by the FAA.


This program developed vacuum windows that could transmit high power microwave/RF energy. This was a necessary enabling technology for plasma heating for nuclear fusion. Strengthened sapphire coupled with stress redistribution has led to a very large experimental increase in load capacity of sapphire windows compared with commercial sapphire. These results were confirmed through modeling and experimental testing. Greatly increased design strength translates into much thinner windows and greatly reduced microwave absorption, which leads to much greater power transmission capability. A MW power level microwave window fixture was designed, modeled, fabricated, and tested. Also as part of the STTR program, a novel resonant ring testing apparatus was designed and used for high power testing at ORNL using inexpensive, low power microwave drivers amplified in the ring.

Department of Energy, Contract # DE-FG02-95ER86038, "Low Loss Sapphire Windows for High Power Microwave Transmission," $600,000, 7 July, 1995, to 30 September, 1999.

Status: Program was successful but superceded by the advent of diamond windows with superior thermal performance.


A low mass, low power, low cost, high temperature prototype furnace was developed for use in space. Vacuum and radiation insulation coupled with low conductive support paths provide a means to almost eliminate heat losses from the furnace, allowing high temperatures to be achieved using low power. A cylindrical configuration provides strength, access, and simplicity. A novel vacuum pump was proposed to use the vacuum of space without losing radiation through the pumping port, while tolerating pulsed back pressure. Core temperatures up to 1000°C can be achieved using less than 100 W of power. Experimentally a furnace was demonstrated achieving 600°C using 50 W of power for a 100 cm3 volume. Cooling is not needed and other support systems are minimal. Direct optical access is provided by heat-reflecting windows. The furnace has the potential to be a centerpiece for research and development of materials processing in space.

NASA Marshall Space Flight Center, Contract # NAS8-99040, "Low Mass, Low Power, Low Cost Space Furnace," $70,000, Dec. 15, 1998 to June 14, 1999.

Status: On hold until space applications develops or NASA interest resumes.


A manufacturing process is being developed for producing a stable high-temperature sapphire fiber cladding. Phase 1 research has demonstrated an adherent, thin, and complete cladding that is stable and inert at high temperatures in oxidizing atmospheres. Sapphire fibers are well suited to the task of sensing harsh environments, tolerating temperatures well above 1500°C and strong chemicals, but a high temperature, inert cladding for these fibers is not commercially available. The details of the cladding process will be defined and optimized. Testing and specification will include the measurement of basic mechanical properties and optical fiber properties at room temperature up to very high temperatures. The detailed equipment and techniques required for production of clad sapphire fibers will be defined. A prototype cladding manufacturing facility will be developed.

DOD, AFOSR Contract # F49620-98-C-0063, "High Temperature Sapphire Fiber Cladding," $100,000, Sept. 1, 1998, to Feb. 28, 1999.

Status: Cladding now available commercially at TvU to temperatures of 1000°C.


This project sought to develop a solid argon binder to allow powder metal injection molding (MIM) of reactive metal parts. Parts made of reactive metals such as titanium are already extensively made using powder metallurgy, but many valuable metals are so reactive at high temperature that any currently available binder will react with and contaminate the part during MIM processing. Solid argon has the proper mechanical behavior and is totally inert. The development of this binder would parallel that of other binders, modified by the conditions of its formation as well as its physical and debinding characteristics that fundamentally change its behavior as a binder. Binder properties, the binder/powder ratio, the mixing procedure, the injection molding process, and the debinding process will be explored experimentally to optimize the process using titanium as the reactive metal powder. Molding and debinding experiments were performed using titanium, however particles without oxide coatings could not be obtained, such that no green strength could be achieved.

NSF Grant # 9760106, "A Novel Binder for Reactive Metal Injection Molding," $100,000, Jan 1 to June 30, 1998.

Status: Alternative titanium sintering techniques have been developed. Concept still valid, but may not be cost effective.


Thoughtventions is developing an aircraft droplet heat exchanger (DHX) to replace the standard metal finned circulating glycol/water heat exchanger. Unmanned aerial vehicles (UAVs) are now being used for atmospheric sampling, but significant advances in aircraft performance must be achieved for sustained flight of large payloads at altitudes up to 30 km. The concept is for a circulating liquid to be sprayed into a ducted airstream to create a uniform dense droplet field that directly transfers heat from the engine cooling liquid to the atmosphere. The droplets are captured at the end of the duct by inertial separation from a sharply turning flow. A droplet heat exchanger efficiently rejects engine heat under widely varying conditions while greatly reducing heat exchanger mass and lowering aircraft drag. Reducing heat exchanger mass increases aircraft altitude capability, and together with decreased drag, increases aircraft range. Heat transfer and droplet collection can be maintained during speed and attitude changes, and the system tolerates rain, snow, and dust. Conceptual feasibility has been demonstrated together with practical experimental droplet production.

NASA Dryden Flight Research Center, Contract # NAS4-97018, "UAV Droplet Heat Exchanger," $70,000, 17 Mar. 1997, to 16 Sept. 1997, DARPA Contract # W31P4Q-09-C-0270, Energy Rejection Systems for Very High Altitude Aircraft, $99,000, Feb 4, 2009 to Aug 3, 2009.

Status: Waiting for demonstrator funding. Various related Particle Heat Exchanger concepts are being pursued at TvU using IR&D funding.


Wall injection of solid hydrogen into the supersonic airstream of a combustor was investigated to provide ultrafast distributed fuel mixing for a practical large scramjet engine NASA Marshall Space Flight Center. Modeling of a solid hydrogen particle ablating in a Mach 3 flow was done to understand the physics of the problem, to predict particle lifetime, and to define the dependence of particle lifetime on the parameters of the problem. Solid hydrogen fueling feasibility was studied to assure that the transport and injection of a particle flow is practical in an engineering sense. Studies indicated that it is practical to pump and inject the solid as a 4 K Solid H2 liquid He with a very low helium fraction; the added helium will not decrease combustion efficiency. High speed single hydrogen pellet injection into an inert gas was performed experimentally to examine actual ablation and verify modeling predictions, but the experiments at the University of Illinois were improperly performed and did not provide useful data. The proposed solid hydrogen fueling would improve fuel distribution and mixing well beyond present concepts, eliminate injector drag, and take advantage of the more standard benefits of a higher fuel density. The data and analysis from modeling, engineering studies, and the pellet experiments were combined to create a strong logical argument that solid hydrogen scramjet fueling is feasible.

NASA Marshall Space Flight Center, Contract # NAS8-40693, "Solid Hydrogen Fueling of a Air Breathing Supersonic Combustor," $70,000, 11 Jan. 1996, to 10 July 1996.

Status: Waiting for demonstration of the high ablation rate of hydrogen or Air Force interest.

U.S. Patent #6,003,300 "Technique for High Mixing Rate, Low Loss Supersonic Combustion with Solid Hydrogen and Liquid Helium Fuel," S.C. Bates, Glastonbury, CT, 1999.


Phase 1 work experimentally demonstrated fiber optic imaging inside a furnace at over 1000°C for the NASA Lewis Research Center. The innovation of this work is the use of a high temperature imaging fiber optic system as a means for non-intrusive diagnosis of high temperature and high pressure engine components and combustion systems, high temperature process development, and as a research tool for system development. Current fiber optic imaging systems provide invaluable access for remote sensing in many applications but are limited in temperature range. A sapphire fiber optic video system was designed, fabricated and tested for basic performance in a furnace in a successful feasibility demonstration.

NASA Lewis Research Center, Contract # NAS3-27568, "High Temperature Fiber Optic Imaging Apparatus," $70,000, 27 Dec. 1994, to 26 June 1995.

Status: Program awaiting development of single sapphire fiber imaging. Sapphire fibers cannot be grown at small enough diameter to allow bundles of small enough size to be made.


This project used auxiliary optical heating and optical diagnostics to control crystal growth in a transparent furnace for the NASA Marshall Space Flight Center. High temperature fiber optics were used to deposit local radiant heat into the crystallizing material. By properly distributing the optical fibers, heat was added to the crystal material through the ampoule, such that the magnitude and spatial pattern of the heating could be controlled and adjusted during crystal growth. This was done in the context of a temperature gradient imposed by standard heating coils. Phase 1 successfully demonstrated feasibility of the concept in a transparent furnace. This system is ideal for the real time control of microgravity crystal growth where gravity driven convection is not present and subtle effects dominate the growth process. These techniques may have many important commercial applications in both the growth of specific crystals and processing capabilities.

NASA Marshall Space Flight Center, Contract # NAS8-40546, "Controlled Crystal Growth Using Auxiliary Optical Heating and Optical Diagnostics," $69,317, 15 Dec. 1994, to 15 June 1995.

Status: Awaiting interest by crystal growers or the start of crystal growth at TvU.


Advanced techniques for heat containment were applied in this NASA Lewis Research Center program to build a transparent furnace operating at 1200°C. Full optical access to furnace applications is needed to diagnose the subtleties of high temperature processes under microgravity conditions, as well as for future applications in process control in space and on earth. Transparent furnaces can be used for research in crystal growth, sintering, metal joining, annealing, high temperature materials properties, and fluid behavior. There are many specific applications in these areas for both NASA and commercial interests. Transparent furnace technology will be a key space station capability, allowing astronauts to interactively perform materials processing experiments in microgravity. The development of a high temperature transparent furnace creates many new opportunities for high temperature material processing research and process control applications. The Phase 2 program will give NASA important new capabilities for advances in materials processing science, and is expected to have broad commercial potential. The furnace was exhibited at the NASA Technology 2007 show in Boston, and then delivered to NASA Lewis for their research.

NASA Lewis Research Center, Contract # NAS3-27664, "High Temperature Transparent Furnace Development," $669,995, 27 Dec. 1993, to 30 September, 1997.

Status: This furnace is an established and sold TvU commercial product.


Feasibility research for the creation of a solid hydrogen pellet combustion apparatus was performed, together with an analysis of pellet behavior and scale-up issues for a full scale propulsion system based on a mixture of a high energy density material (HEDM) in solid hydrogen. A detailed design of a solid hydrogen pellet injector, a detailed design of a pulse combustor to be used for combustion of these pellets, a preliminary model of pellet ablation, techniques for rapid hydrogen gas to solid condensation, techniques for high mass flux pumping of solid hydrogen, and a compilation of the engineering properties of solid hydrogen were developed. An experimental program was developed to fuel a pulse combustor with solid hydrogen pellets that would allow studies of both the combustion behavior of the solid hydrogen and the material itself.

USAF Phillips Laboratory, Contract # F04611-93-C-0086, "Prototype Cryogenic Solid Hydrogen Storage and Pellet Injection," $74,995, 30 June to 30 Dec. 1993.

Status: Concept was impractical. Associated solid hydrogen and solid hydrogen pellet work is ongoing.

Thoughtventions Unlimited LLC
40 Nutmeg Lane
Glastonbury, CT 06033
Tel: (860) 657-9014
E-Mail: thought@tvu.com


Last updated: April 2017