New methods for harvesting waste energy can allow for reduced fossil fuel-dependence, off-grid power generation and more efficient vehicles and buildings. Traditional thermoelectric materials can be used for these applications; however, their use is limited due to their relatively low thermal conductivities and low melting temperatures. The proposed research project centers on a new thermal-to-electrical energy harvesting/conversion method comprised of a capillary-sized heat pipe filled with magnetic fluid that operates via temperature difference. When the magnetic fluid inside the oscillating heat pipe (OHP) is exposed to a solenoid, an electrical alternating-current is generated. The high thermal conductivity and temperature stability of OHPs will allow for their utilization in conditions and applications where traditional thermoelectric materials are not viable. This new waste-heat recovery process will provide a new method for energy recovery and thermal management in a wide range of energy efficient applications.
The project's research objective is to better understand "thermofluidic induction" a unique thermo-kinetic-electromagnetic energy conversion process inherent to temperature-driven flow of magnetic nanofluid near a solenoid which can result in heat transfer enhancement and electrical power generation. Well-designed experiments on various OHP platforms will be conducted to determine the influence of the design and operating parameters on the performance of these OHPs in terms of heat flux and electrical power generation. Various nanofluids will be synthesized and then characterized using a wide range of techniques, including dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM), in order to determine their physical and thermal characteristics before and after OHP-operation. The effects of thermal fatigue and nanoparticle settling will be studied. A transparent OHP will also be constructed to better understand the extent to which the nanofluid and OHP operating parameters affect energy harvesting, fluid mechanics and heat transfer. Thermo-kinetic-electromagnetic modeling will be accomplished by utilizing and modifying available multiphysics software on select OHP models. The research objectives are to determine: (1) the extent to which the magnetic field and heat transfer are coupled in thermally-driven, pulsating capillary flow of ferro-nanofluid near a solenoid, (2) how to effectively transfer heat and/or generate a magnetic field in an oscillating heat pipe by varying specific design parameters, (3) the extent to which thermally-driven, pulsating capillary flows of ferro-nanofluids can: (i) enhance heat transfer and/or (ii) affect nanoparticle suspendability (agglomeration) and particle size/distribution (i.e. thermal fatigue of nanofluids) and finally (4) a novel, multiphysics analytical/numerical model that aids in predicting heat transfer and electrical power generation inherent to thermofluidic induction.
