From 2007 to 2021

Recent research progress has proven that hybrid nanofluids (HNFs) are superior to single-particle nanofluids (SPNFs) and traditional thermal fluids. This article attempts to review and conduct a bibliometric study on hybrid nanofluid research (HNFR) to foster well-informed future research. The HNFR covered the properties (thermal, optical, and tribological), convective flow and heat transfer performance in different channels, enclosures, ducts, and thermal transfer applications, lubrication and cooling characteristics (machining, rolling, and automobile parts), and thermal energy storage characteristics. Data of scientific publications on HNFR were sourced from the SCOPUS database from 2007 to 2021 to conduct bibliometric analysis using VOS viewer. HNFR showed an increasing growth in scientific publications from 2007 (2 articles) to 2021 (663 articles) with a total of 1644 articles, indicating the growing and wide acceptance of HNFs as advanced thermal media. Engineering (with 32% of publications) is the field of study that participated most in HNFR with MWCNT, water, and thermal conductivity as the most studied nanoparticle, base fluid, and property, respectively. The bibliometric study showed that Pop I., Ton Duc Thang University, and India are the most productive author, institution, and country that participated in HNFR, respectively. Suresh (2012) and the Journal of Thermal Analysis and Calorimetry are the most cited article and journal with 430 and 2624 citations, respectively. In addition, the Ton Duc Thang University (Vietnam) is the highest funder regarding HNFR. Top research topics involved the determination of thermophysical properties of HNFs, heat transfer and flow performance for natural and mixed convection, and magnetohydrodynamics. In addition to the need to intensify studies on HNFs, future research outlook involves the utilization of electric and magnetic stimulus, bio-based and magnetic HNFs, green and ionic base fluids, turbulators, and optimization of mixing ratio of hybrid nanoparticles.