航天飞机热控系统纳米流体冷却剂的优化

The addition of metal nanoparticles to coolants used in
thermal control systems can dramatically increase the
thermal conductivity of the base fluid. Such metal
nanoparticle-fluid composite materials are referred to as
nanofluids and their use as coolants has the potential to
reduce the weight and power requirements of spacecraft
thermal control systems. The thermal conductivity of
nanofluids is dependent on the concentration, size,
shape, surface chemistry, and aggregation state of the
constituent nanoparticles. The effects of nanoparticle
loading concentration and the aspect ratio of the
nanoparticles on the thermal conductivity and viscosity of
water and ethylene glycol based coolants were
investigated. Silver nanorods with a diameter of 55 ± 12
nm and an average length of 12.8 ± 8.5 m at a
concentration of 0.5% by volume increased the thermal
conductivity of water by 68%. The thermal conductivity of
an ethylene glycol based coolant was increased by 98%
with a silver nanorod loading concentration of 0.5% by
volume. Longer nanorods had a greater effect on the
thermal conductivity than shorter nanorods at the same
loading density. However, longer nanorods also
increased the viscosity of the base fluid to a greater
extent than shorter nanorods. TCi导热系数仪