On Heat Transfer enhancement in Diesel Engine Cylinder Head Using γ-Al2O3/water nanofluid with different nanoparticle sizes
In the current work, an experimental investigation of γ-Al2O3/water characteristics nanofluid was performed for convective cooling of engine cylinder head for fully developed turbulent regime. Nanoparticles of different sizes were mixed in distilled water with constant volume fraction of 1% through the experiments. The cylinder head was simulated as a rectangular duct, of an aspect ratio of 0.8, with a cast iron test specimen from actual cylinder head of diesel engine. The effect of different nanoparticle sizes (30, 100, and 150 nm), bulk temperature (60°C, 70°C, and 80°C), and flow velocity (1, 1.5 and 2 m/s) were investigated at variable heat fluxes. The experimental results revealed that the obtained enhancement of convective heat transfer coefficient is inversely proportional to both nanoparticle diameter and bulk temperature and directly proportional to the coolant flow velocity. Also, the highest achieved enhancement over the pure base fluid in heat transfer coefficient is 88.74% at 30 nm particle size. The γ-Al2O3/water nanofluid showed promising results for intensive study with different operating conditions.