The last two decades have seen exponential increases in the power density and complexity of electronic and optical systems. These power density increases also demand more advanced thermal management strategies. Additionally, worldwide energy consumption associated with space cooling has increased substantially thereby demanding more efficient space cooling technologies.
Mainstream has been performing R&D in thermal control technology since its inception in 1986. This research ranges from fundamental characterization of heat and mass transport phenomena to the development of improved efficiency, ruggedized, military environmental control units that consume less logistic fuel than legacy systems.
Most of Mainstream’s thermal-fluids R&D is funded by federal sponsors including the Army, Navy, Air Force, the Department of Energy (DOE), NASA, and the National Science Foundation (NSF), among others. We also have excellent working relationships with many industrial partners who utilize Mainstream’s expertise and experience in thermal control technology.
Our thermal control technology R&D is focused on the following four areas:
Military Environmental Control Products
Space cooling and refrigeration are responsible for a large portion of the fuel consumption among deployed troops. As a result, the DoD is constantly demanding more efficient environmental control units (ECUs) and refrigeration units (RUs). Mainstream is well positioned in this field with our high-efficiency improved environmental control units (IECU) for rigid-walled shelter cooling, our ducted modular environmental control units (MECUs) for tent cooling, and our containerized RU for food, ice, and reserve blood supply storage. All of these units are ruggedized for the military environment and are constantly being refined for enhanced efficiency and reliability. See our Products page for more information.
- Four IECU variants for through-wall cooling: 9,000-36,000 Btu/hr (3/4 – 3 tonR), both single- and three-phase power
- ECUs for duct-fed cooling: 5-tonR ducted ECU currently in production, and a 3-tonR variant in development
- RUs for tricon and quadcon containers: function as a freezer, refrigerator, or heater to maintain container setpoints from -10 to 60°F (pictured)
Purpose-Built Thermal Management Systems
Federal and commercial entities frequently need purpose-built thermal management systems (TMSs) for atypical applications. Mainstream has developed TMSs for cooling of communication equipment on Venus, cooling of high energy laser weapon systems, cooling of wide bandwidth radar jamming electronics, and many other exotic applications where thermal management is critical to functionality.
- Single-phase and two-phase laser weapon cooling systems (TMS for the Office of Naval Research’s High Energy Fiber Laser (HEFL) program pictured)
- Man-portable micro-climate TMSs for soldier and HAZMAT personnel cooling
- Modular cooling systems for rack-mounted high power electronics
High Heat Flux Cooling Component Development
As the power density of central processing units, radar electronics, laser diodes, and other high power electronic components increases, so do the cooling demands. Mainstream specializes in the cooling of high heat flux components and has developed many novel technologies to enhance local heat transfer coefficients.
- Synthetic jets in microchannels generate turbulent-like heat transfer coefficients even when the bulk flow is laminar (pictured – click image to play animation)
- Cavitation-enhanced microchannel cooling increases the thermodynamic quality range over which annular flow occurs
- Saturated spray cooling for ultra-high heat flux
Thermal Energy Storage Component Development
Thermal energy storage (TES) has a variety of applications in real-world systems. Off-peak load-shifting for space cooling, electronic overheat mitigation, isothermal boundary control, and pulsed power (i.e. laser) systems are a few potential uses of thermal energy storage materials and devices. Mainstream has developed phase change material (PCM) â€“based TES devices for a number of military and commercial applications. Porous heat spreaders can be added to the PCM to form a composite that increases the storage and recharge rate in more demanding applications.
- Experimentally validated PCM TES device multiphysics modeling (pictured – click image to play animation)
- Heat spreader/PCM composites demonstrated in high vibration environments and for over 2,800 thermal cycles
- TES technology meshes well TMS and high heat flux focus areas
Our Labs and Capabilities
Mainstream has a diverse set of capabilities for the development of thermal control solutions including:
- Brass-board system characterization
- Simulated environments and environmental cycling
- Heat transfer coefficient measurements
- Commercial finite element analysis (FEA) and computational fluid dynamics (CFD) tools
- Computational process analysis software tools
Mainstream’s 85,000-ft2 facility in Rockledge, FL includes extensive laboratories and supporting facilities. The facilities used most often for our thermal control technology programs are:
- Simulated environment chamber
- High power thermal lab
- Low power thermal lab (for brass-board demonstrations, fundamental heat transfer measurements, etc.)
- CNC machine shop (for prototype development that includes 5-axis CNC mill, several 4-axis mills and lathes, welding facilities)