*Proceeding Paper* **Heat Transfer Enhancement in Louvered Fin Flat Tube Radiator Using Hybrid Nanofluids †**

**Waqar Ali \*, Abid Hussain, Ahmed Usman, Khalid Mahmood, Muhammad Mubashir Iqbal and Haris Khan**

Mechanical Engineering Department, University of Engineering and Technology, Taxila 47050, Pakistan; abid.hussain@uettaxila.edu.pk (A.H.); muhammadmubashar928@gmail.com (M.M.I.)

**\*** Correspondence: waqaralibalti1996@gmail.com

† Presented at the Third International Conference on Advances in Mechanical Engineering 2023 (ICAME-23), Islamabad, Pakistan, 24 August 2023.

**Abstract:** This research explores the potential of hybrid nanofluids to improve the thermal efficiency of a car's louvered fin flat-tube radiator. Hybrid nanofluids were prepared by combining distilled water with a 0.1% vol. concentration of SiO2 and MWCNT nanoparticles, using different ratios of nanoparticles: 80:20, 50:50, and 20:80. The experimental analysis focused on examining the heattransfer performance of the radiator. The results clearly demonstrated a significant improvement in the radiator's thermal performance when using hybrid nanofluids. These nanofluids effectively enhanced the rate and coefficient of heat transfer. Notably, an increase of 15.6% in the Nusselt number was observed with the SiO2–MWCNT 20:80 water containing a 0.1% volumetric concentration of nanoparticles. Overall, the findings highlight the promising application of hybrid nanofluids in boosting the thermal efficacy of car radiators.

**Keywords:** hybrid nanofluids; flat tube radiator; CFD; thermal performance; heat-transfer coefficient
