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Heat Transfer Characteristics on Toroidal Convection Loop with Nanofluids

나노유체 토로이달 자연대류 루프에서의 열전달 특성

  • 장주찬 (충북대학교 대학원 기계공학부) ;
  • 이석호 (충북대학교 기계공학부) ;
  • 이충구 (충북대학교 기계공학부)
  • Published : 2009.04.01

Abstract

Experimental studies on single-phase toroidal circulation loop(thermosyphon) have been performed in the present study with Ag-nanofluids as a working fluids. The present paper deals with an experimental study on the heat transfer behavior of single-phase toroidal loop. Toroidal loop charged with nanofluid has been constructed and a number of tests have been carried out. Different geometric parameter, e.g., orientation has been investigated. The tests were conducted employing two fluids: distilled water and Ag-nanofluid of various volume concentrations. The experiments at Rayleigh number from $10^5$ to $10^6$ showed a systematic and slight deterioration in natural convective heat transfer. It was observed that the deterioration due to the particle concentration was in the range of 5-10%. At a given particle concentration of 0.05%, abrupt decrease in the Nusselt number and the Raleigh number was observed. The present study with toroidal loop shows that the application of nanofluids for heat transfer intensification should not be decided only by the effective thermal conductivity with increasing particle concentration.

Keywords

References

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