Assessment of the Use of Nanofluids in Spacecraft Active Thermal Control Systems

Abstract

The addition of metallic nanoparticles to a base heat transfer fluid can dramatically increase its thermal conductivity. These nanofluids have been shown to have advantages in some heat transport systems. Their enhanced properties can allow lower system volumetric flow rates and can reduce the required pumping power. Nanofluids have been suggested for use as working fluids for spacecraft Active Thermal Control Systems (ATCSs). However, there are no studies showing the end-to-end effect of nanofluids on the design and performance of spacecraft ATCSs.In the present work, a parametric study is performed to assess the use of nanofluids in a spacecraft ATCSs. The design parameters of the current Orion capsule and the tabulated thermophysical properties of nanofluids are used to assess the possible benefits of nanofluids and how their incorporation affects the overall design of a spacecraft ATCS. The study shows that the unique system and component-level design parameters of spacecraft ATCSs render them best suited for pure working fluids. The addition of nanoparticles to typical spacecraft thermal control working fluids actually results in an increase in the system mass and required pumping power. The addition of metallic nanoparticles to a base heat transfer fluid can substantially increase its thermal conductivity. These nanofluids have been shown to have advantages in some heat transport systems. Their thermal properties allow the system volumetric flow rate to be reduced, thus reducing the required pumping power. Nanofluids have been suggested as working fluids in spacecraft Active Thermal Control Systems (ATCSs). However, spacecraft ATCSs are unique in that they have stringent temperature control requirements and use specialized heat transfer devices. In the present work, a parametric study was performed to assess the use of nanofluids in spacecraft ATCSs. The tabulated thermophysical properties of various nanofluids, the design requirements of NASA's Orion ATCS and the performance parameters of its key heat transfer components were used to assess the effects of the incorporation of nanofluids. The study shows that the unique system and component-level design parameters of spacecraft ATCSs do not lend themselves to the use of nanofluids. The addition of nanoparticles to typical spacecraft internal flow loop working fluids actually results in an increase in either the system mass or the required pumping power, the opposite of the hoped-for effect. The intermediate results obtained in the study also suggest that that the addition of nanoparticles to an external ATCS loop is not likely to result in a significant overall system benefit.

Numerical and experimental analysis of performance in a compact plate heat exchanger using graphene oxide/water nanofluid

“…Plate heat exchangers PHEs are widely used in manufacturing and engineering applications since early 1930s due to lesser in price, compact in size, ease of maintenance and installation, better thermal efficiency, lesser pressure drop and pumping power. The motive for working on PHE with nanofluids as coolants comes from a parametric study performed to estimate usefulness of nanofluids for dissipating heat from Active Thermal Control systems of NASA's Orion Capsule (Ungar and Erickson, 2011). The PHE with nanofluid as coolant is useful in chemical processing units, electronics cooling systems, aerospace application for cooling aircraft fluids, power industry for transformer cooling, etc.…”

Finite element modeling of conjugate mixed convection flow of Al2O3–water nanofluid from an inclined slender hollow cylinder

“…Choi [20] described the thermal conductivity enhancement potential of fluids composed of nanometer-sized particles (nanoparticles, nanofibers, nanotubes, nanowires, nanorods, nanosheets or droplets) dispersed in a base fluid which he designated as 'nanofluids'. The main driving force for nanofluid dynamics research lies in a wide range of applications which include astronautical [21], medical [22,23], materials processing [24], solar energy systems [25] and propulsion and combustion engineering [26,27]. Significant computational and mathematical studies of thermal convection flows of nanofluids have therefore appeared.…”

Selected aspects of the nanofluids utilization as the heat transfer carriers

“…The effect of nanofluids utilization in a spacecraft active thermal control system was assessed from a system perspective [53]. A detailed analysis based on the special thermal system specifications, requirements, and component performance showed that the addition of nanofluids to the internal fluid loop (the whole system consisted of -"internal" and "external" loops, however the results are presented only for the internal one) did not result in the mass or power benefits.…”