SBIR Phase I: Electro-Mechanical Micro-Vibratory Transducers for Convective Heat Transfer Enhancement

This Small Business Innovation Research (SBIR) Phase I project is focused on developing a method to adapt the use of a novel electro-mechanical micro-vibratory transducer to enhance convective heat transfer rates in heat exchangers while minimizing any added flow pressure drop. The transducer is composed of a very thin, light weight composite sheet that contains the combination sensors and vibratory actuators that are used to detect boundary layer flow conditions and to excite the viscous wall layer to control boundary layer transition and separation. The innovative approach uses localized sub-micron level wall vibrations to increase the wall skin friction while attenuating the overall turbulence level in the flow. This is expected to lower the flow pressure drop increase compared to traditional forms of heat transfer enhancement through turbulence enhancement. The power consumption of the transducer is also about three orders of magnitude smaller than the best competing active flow control devices and is expected to be insignificant in comparison to the heat transfer rates. The transducer can be easily integrated to plates, fins or tubes on the airside of a heat exchanger. The commercial viability is that it can improve waste heat recovery and utilization for manufacturing and processes industries involving gaseous phase drying. It can also make stationary and vehicle mounted heating ventilating and air-conditioning (HVAC) and power generation systems more compact and efficient. It can allow denser packaging of electronic components by facilitating heat dissipation in a smaller space.