<span style="font-size:15.0pt;mso-bidi-font-size:16.0pt;color:black;letter-spacing: -.05pt" lang="EN-US">Effect of heat transfer enhancement and NO_x emission using <span style="font-size:15.0pt;mso-bidi-font-size:16.0pt" lang="EN-US">Al₂O₃/water nanofluid as coolant in CI engine </span></span>

Abstract

<span style="font-size:9.0pt;mso-bidi-font-size:12.0pt;color:black;letter-spacing: -.25pt" lang="EN-US">Heat transfer characteristics of <span style="font-size:9.0pt;mso-bidi-font-size:12.0pt" lang="EN-US">Al₂O₃/water nanofluids are studied in a shell and tube heat exchanger under laminar flow condition when used as coolant for a single cylinder diesel engine.<b style="mso-bidi-font-weight:normal"> </b>Nanofluids are prepared using the two-step method with various volume concentrations of 0.5, 1, 1.5 and 2%. The effect of Peclet number and various volume concentrations on heat transfer characteristics and pressure drop is investigated under laminar flow condition. Based on the results, an increase in volume concentration of nanoparticles in the base fluid causes significant enhancement of heat transfer characteristics compared to distilled water. At a Peclet number of about 3000, the enhancement of the overall heat transfer coefficient at 0.5, 1, 1.5 and 2% Al₂O₃ nanoparticle volume concentration was about 11%, 18%, 23% and 25%, respectively under no load condition . The measured pressure loss with the use of nanofluids is almost negligible when compared to water at all Peclet numbers. Experiments are also performed on a diesel engine to assess the effect of nanofluids on its emission characteristics. The investigation shows that using nanofluids resulted in 12.5% reduction of NOx emissions at full load and about 3-5% at no load and part load.<b style="mso-bidi-font-weight:normal"></b>

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