Influence of surfactants on thermal performance of Al2O3/water nanofluids in a two-phase closed thermosyphon
Seungyeop Baek, Dongwook Shin, Jung-Pil Noh, Byeong-Keun Choi, Sunchul Huh, Hyomin Jeong, Yonmo Sung
Abstract
An experimental study was conducted to investigate the effect of surface tension and thermal conductivity of distilled water (DW) and 0.5 wt% alumina nanofluid with or without 1.5 wt% SDBS on a two-phase closed thermosyphon (TPCT). The TPCT thermal performance test was performed under varying conditions of filling ratio (30%, 50%, and 70%) and heat input power (5, 10, and 15 W). The surface tension and thermal conductivity of the working fluids were compared to confirm the effect of adding 1.5 wt% SDBS to DW and 0.5 wt% alumina nanofluid at 298 and 293 K, respectively. The surface tension of the DW decreased by approximately 58.7%, while the thermal conductivity decreased by approximately 2.1%. When the thermal conductivities of the DW and alumina nanofluids were almost the same, the decrease in the surface tension of the working fluids, approximately 6.7%, could reduce the thermal resistance. Even with a 58.7% decrease in surface tension and 2.1% decrease in thermal conductivity, the thermal resistance of the TPCT decreased. However, with a 58.3% decrease in surface tension and 5.6% decrease in thermal conductivity, the thermal resistance increased.