Hydrodynamic effects of hybrid nanofluid jet on the heat transfer augmentation

Abstract

In industrial and energy systems, precise temperature control is indispensable. This study investigates the impact of hybrid nanofluids and certain jet hydrodynamic effects on enhancing the cooling efficiency on a heated copper surface. γ-Al2O3-MWCNT/water hybrid nanofluids consisting of Aluminum oxide (Al2O3) and Multi-Walled Carbon Nanotube (MWCNT) in de-ionized water with a mixing ratio of 60:40 was prepared and characterized. Nanofluid volume fraction (0.05 vol% ≤ Φ ≤ 0.3 vol%) and jet hydrodynamic parameters; dimensionless jet-to-target gap (1 ≤ β ≤ 5), dimensionless jet diameter (0.05 ≤ Ⴋ ≤ 0.17), and Reynolds number (8000 < Re < 28,000) were examined. In comparison to de-ionized water, peak heat transfer enhancement of approximately 21% was achieved with this jet cooling system, with nanofluid volume fraction (Φ = 0.3 vol%), Reynold number (Re ≈ 15,000) jet-to-target gap (β = 4), and dimensionless jet-diameter (Ⴋ = 0.10). Generally, the study reveals that the heat transfer rate increases with Reynolds number, and nanofluid volume fraction, but varies with jet-to-target gap, and jet-diameter. Jet-to-target gap (β = 4) and dimensionless jet diameter (Ⴋ = 0.10) are optimum jet hydrodynamics settings for best cooling performance. The hybrid nanofluid had better thermal augmentation than de-ionized water in all cases examined.

Keywords

• Jet impingent cooling
• Heat transfer enhancement
• Nanofluid
• Hydrodynamic effect