Hybrid Nanofluids for Enhanced Liquid Cooling in Pumped Loops

The adoption of a universal extended-life coolant (ELC) formulation to service the Army’s ground and airborne vehicles will dramatically reduce the maintenance burden and waste associated with the use of conventional, supplemental coolant additive based engine coolants, allowing maintenance intervals to be extended from annual to 5-year or longer schedules. This transition presents an opportunity to introduce novel inorganic additives to provide enhanced heat transfer efficiency across a wide range of military equipment. The proposed effort envisions the development of “Smart Coolant” technology, allowing for a unique heat transfer enhancement in ELCs which can be specifically tailored to the operational temperatures of internal combustion engines. The resulting smart coolant will not only enhance the cooling system’s heat transfer efficiency, but it will also provide a unique heat-sinking effect at high temperatures to better stabilize operational temperatures and provide greatly enhanced protection for engines in danger of overheating. The present program is a collaboration between NEI Corporation and North Carolina A&T State University (STTR partner) and an industrial partner. The proposed Phase II program builds upon the substantial progress made in Phase I towards providing a significant enhancement in the thermal efficiency of advanced coolants for use in U.S. Army vehicles using a small concentration of well dispersed and stable nanoparticles which have the unique ability to remove heat from the cooling system over a desired temperature range, only releasing that heat when engine temperatures have normalized. Proof of concept was demonstrated in Phase I. In addition, the structure and morphology of the nanoparticles was characterized, providing a path for optimization in Phase II. The primary objective of the Phase II program is to scale the nanoparticle synthesis process such that optimized samples of sufficient volume may be produced to allow for more extensive study and to facilitate more extensive standardized and field testing. This will allow us to demonstrate the commercial feasibility of manufacturing an enhanced, universal, smart coolant suitable for use in the Army’s ground and airborne platforms. The proposed Phase II effort combines NCA&T’s unique bottom-up nanoparticle synthesis process, and NEI’s extensive experience in nanofluid development and commercialization, to create novel smart coolants with unique protective properties. The goal is to provide the Army with a universal HD ELC smart coolant technology with significant enhancement in heat transfer efficiency, in the range of 25-50%. The Phase II work plan includes nanoparticle synthesis optimization, process scale-up, coolant dispersion optimization, characterization, standardized testing and analysis, culminating in the delivery of a 5-gallon quantity of smart coolant to the Army for testing and validation. We expect the TRL to be 5 at the end of the Phase II program.