International Journal of Advanced Engineering Application

Experimental Investigation on Heat Transfer Enhancement and Pressure Drop Characteristics of Al₂O₃, TiO₂ and ZnO Nanofluids in a Shell-and-Tube Heat Exchanger Under Turbulent Flow Conditions

Author(s):Suresh Chandra Patel, Meenakshi Devi, Rajiv Nair, Prashant Kulkarni

Affiliation: Department of Mechanical Engineering, Jadavpur University, Kolkata, West Bengal, India Department of Chemical Engineering, Heritage Institute of Technology, Kolkata, West Bengal, India

Page No: 79-85

Volume issue & Publishing Year: Volume 3, Issue 5, May 2026

Journal: International Journal of Advanced Engineering Application (IJAEA)

ISSN NO: 3048-6807

DOI:

Download PDF Cite this article

Abstract:
Enhancement of convective heat transfer in shell-and-tube heat exchangers (STHXs) through substitution of conventional working fluids with engineered nanofluids represents a compelling strategy for reducing heat exchanger size and pumping energy in process industry applications. This study presents a systematic experimental investigation of the heat transfer enhancement and pressure drop penalties associated with three oxide nanofluids — aluminium oxide (Al₂O₃), titanium dioxide (TiO₂), and zinc oxide (ZnO) — suspended in distilled water at volumetric concentrations of 0.1, 0.3, and 0.5% (v/v), tested in a single-pass counter-flow STHX (shell diameter 90 mm, 7 copper tubes of 10 mm OD, tube length 1000 mm) under turbulent flow conditions (Re = 2000–12000). Nanoparticle suspensions were prepared by the two-step method with polyvinylpyrrolidone (PVP) surfactant (0.1 wt%) and characterised for particle size distribution, zeta potential, thermal conductivity, and dynamic viscosity as functions of temperature (20–70°C). The Al₂O₃/water nanofluid at 0.5 vol% achieves the highest Nusselt number enhancement of 50.4% over base fluid at Re = 12000, at the cost of a 25.7% pressure drop increase. A Performance Evaluation Criterion (PEC) analysis, incorporating both heat transfer enhancement and pumping power penalty, identifies Al₂O₃/water at 0.3 vol% as the optimum nanofluid with a PEC index of 1.148 — the highest net benefit among all tested compositions. New empirical Nusselt number correlations of the Dittus-Boelter form incorporating nanoparticle volume fraction are proposed and validated against experimental data with mean absolute error below 4.2%. Zeta potential measurements (−39.4 to −48.2 mV) confirm adequate electrostatic stabilisation of all nanofluid dispersions throughout testing.

Keywords: nanofluid, Al₂O₃, TiO₂, ZnO, shell-and-tube heat exchanger, Nusselt number, heat transfer coefficient, pressure drop, PEC, turbulent flow, thermal conductivity, Dittus-Boelter

Reference:

• [1] Choi, S. U. S., & Eastman, J. A. (1995). Enhancing thermal conductivity of fluids with nanoparticles. ASME FED, 231, 99–105.
• [2] Das, S. K., Choi, S. U. S., & Patel, H. E. (2006). Heat transfer in nanofluids: A review. Heat Transfer Engineering, 27(10), 3–19.
• [3] Duangthongsuk, W., & Wongwises, S. (2009). Heat transfer enhancement and pressure drop characteristics of TiO₂/water nanofluid in a double-tube counter flow heat exchanger. International Journal of Heat and Mass Transfer, 52(7–8), 2059–2067.
• [4] Eastman, J. A., Choi, S. U. S., Li, S., Yu, W., & Thompson, L. J. (2001). Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles. Applied Physics Letters, 78(6), 718–720.
• [5] Gnielinski, V. (1976). New equations for heat and mass transfer in turbulent pipe and channel flow. International Chemical Engineering, 16(2), 359–368.
• [6] Heris, S. Z., Etemad, S. G., & Esfahany, M. N. (2006). Experimental investigation of oxide nanofluids laminar flow convective heat transfer. International Communications in Heat and Mass Transfer, 33(4), 529–535.
• [7] Koo, J., & Kleinstreuer, C. (2005). A new thermal conductivity model for nanofluids. Journal of Nanoparticle Research, 6(6), 577–588.
• [8] Lotfi, R., Saboohi, Y., & Rashidi, A. M. (2010). Numerical study of forced convective heat transfer of nanofluids: Comparison of different approaches. International Communications in Heat and Mass Transfer, 37(1), 74–78.
• [9] Pak, B. C., & Cho, Y. I. (1998). Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles. Experimental Heat Transfer, 11(2), 151–170.
• [10] Patel, H. E., Das, S. K., Sundararajan, T., Sreekumaran Nair, A., George, B., & Pradeep, T. (2003). Thermal conductivities of naked and monolayer protected metal nanoparticle based nanofluids. Applied Physics Letters, 83(14), 2931–2933.
• [11] Timofeeva, E. V., Gavrilov, A. N., McCloskey, J. M., Tolmachev, Y. V., Sprunt, S., Lopatina, L. M., & Selinger, J. V. (2007). Thermal conductivity and particle agglomeration in alumina nanofluids. Physical Review E, 76(6), 061203.
• [12] Vajjha, R. S., & Das, D. K. (2009). Experimental determination of thermal conductivity of three nanofluids and development of new correlations. International Journal of Heat and Mass Transfer, 52(21–22), 4675–4682.
• [13] Xuan, Y., & Li, Q. (2003). Investigation on convective heat transfer and flow features of nanofluids. Journal of Heat Transfer, 125(1), 151–155.
• [14] Yu, W., France, D. M., Routbort, J. L., & Choi, S. U. S. (2008). Review and comparison of nanofluid thermal conductivity and heat transfer enhancements. Heat Transfer Engineering, 29(5), 432–460.
• [15] Zeinali Heris, S., Nasr Esfahany, M., & Etemad, S. G. (2007). Numerical investigation of nanofluid laminar convective heat transfer through a circular tube. Numerical Heat Transfer Part A, 52(11), 1043–1058.