Papers by HAMZA BABAR
International Journal of Heat and Mass Transfer, 2025
Efficient thermal management is critical in high-power-density systems found in electronics, elec... more Efficient thermal management is critical in high-power-density systems found in electronics, electric vehicles, renewable energy devices, aerospace platforms, and data centres. This study aims to enhance thermal performance through the development of nature-inspired heat sink geometries integrated with advanced nanofluids. Two novel biomimetic configurations, Inline Arranged Airfoil Integrated Curvilinear Pin-Fin (IACPF) and Inline Arranged Airfoil Integrated Corrugated Curvilinear Pin-Fin (AICCPF) were experimentally evaluated across heating powers of 75-300 W and flow rates ranging from 200 to 450 mL/min. These heat sinks were tested using mono and hybrid nanofluids formulated with silver (Ag), silicon carbide (SiC), and beryllium oxide (BeO) nanoparticles, chosen for their high thermal conductivity, dispersion stability, and economic viability. The experimental methodology focused on assessing thermal and hydraulic performance through key parameters including Nusselt number, thermal resistance, wall temperature, and pressure drop. Comparative study showed that, using water as the working fluid at 75 W, the AICCPF heat sink delivered a 10.23% improvement in Nusselt number over the IACPF. When benchmarked against a conventional straight-channel heat sink, the AICCPF design at 150 W demonstrated a 103% enhancement in Nusselt number, confirming its geometric effectiveness. Among nanofluids, the highest convective enhancement was achieved using Ag/SiC hybrid nanofluid, yielding a peak improvement of 22.29% in the AICCPF configuration. Pressure drops remained within manageable limits, with a maximum increase of 15.86%. These findings demonstrate that combining biomimetic heat sink architectures with thermally optimised nanofluids achieves high thermal performance while maintaining acceptable hydraulic penalties. The proposed approach offers scalable, energy-efficient solutions for next-generation cooling applications.
Journal of Molecular Liquids, 2019
The objective of compiling this study is to seek the attention of young scholars and experts work... more The objective of compiling this study is to seek the attention of young scholars and experts working in the field of heat transfer by discussing the applications and challenges of hybrid nanofluids with a concise discussion on its history, synthesis techniques, thermophysical properties, research gaps, future directions, current status, and the leading groups, organizations, and countries around the world. Applications in different fields like solar energy, heat pipes, automotive industry, manufacturing industry, heat exchangers, cooling of electronic equipment's etc. have been reviewed and discussed in this study. Nanofluids are part of these inventions that possess the ability of uprising the field of heat transfer, but instead of its superior thermal, electrical, and optical properties, advancement in the form of hybrid nanofluids and a numerous study conducted around the world, investigators and manufacturers are still facing the problem of practicing nanofluids in heat transfer devices used commercially and even in an individual's life. This problem works like a magnet, capturing the attention of research societies working around the world by inspiring them to take control and lead this field to the destination of domestic and commercial implementation. With the help of this article, authors endeavored to identify some important work orientations and existing problems that interrupted its performance and implementation for the convenience of captivated scholars. The most recent research work has improved the thermophysical properties of nanofluids by introducing hybrid nanofluids, working on preparation techniques, and by adding the surfactants to improve its stability but still need a lot of attention for the development of correlations/models that can predict the thermophysical properties and heat transfer characteristics, to make it cost-effective, improve its stability, and finally its implementation.
The purpose of carrying out this research work is to further amplify the advantages of implementi... more The purpose of carrying out this research work is to further amplify the advantages of implementing geothermal air conditioning system in Pakistan. The temperature of the soil at a certain depth remains consistent irrespective of the ambient temperature, the consistency in temperature of the soil all over the year provides a new way to the researchers, scholars, and scientists to work on the different techniques and methods of extracting the energy of ground for heating and cooling applications. To effectively utilize the natural source of energy (geothermal energy), a heat-exchange system has to be constructed. This is typically an arrangement of pipes with selected piping material and loop design, buried in the ground. Among many available circulating mediums, air and water are most widely used to harness energy from the ground in winter and vice versa in summer. A similar system has been proposed that can provide a sustainable solution for the alarming energy crisis in Pakistan. Soil temperature at a certain depth, adequate piping material, configuration and the coefficient of performance (COF) of the installed system evaluated experimentally. The temperature gradient of 23°C on average has been achieved from the developed working model.
Titanium dioxide (TiO 2) has been used extensively because of its unique thermal and electric pro... more Titanium dioxide (TiO 2) has been used extensively because of its unique thermal and electric properties. Different techniques have been used for the preparation of TiO 2 nanofluids which include single-step and two-step methods. In the natural world, TiO 2 exists in three different crystalline forms as anatase, brookite, and rutile. Nanoparticles are not used directly in many heat transfer applications, and this provides a major challenge to researchers to advance towards stable nanofluid preparation methods. The primary step involved in the preparation of nanofluid is the production of nano-sized solid particles by using a suitable technique, and then these particles are dispersed into base fluids like oil, water, paraffin oil or ethylene glycol. However, nanofluid can also be prepared directly by using a liquid chemical method or vapor deposition technique (VDT). Nanofluids are mostly used in heat transfer applications and the size and cost of the heat transfer device depend upon the working fluid properties, thus, in the past decade scientists have made great efforts to formulate stable and cost-effective nanofluids with enhanced thermophysical properties. This review focuses on the different synthesis techniques and important physical properties (thermal conductivity and viscosity) that need to be considered very carefully during the preparation of TiO 2 nanofluids for desired applications.
Titanium dioxide (TiO 2) has been used extensively because of its unique thermal and electric pro... more Titanium dioxide (TiO 2) has been used extensively because of its unique thermal and electric properties. Different techniques have been used for the preparation of TiO 2 nanofluids which include single-step and two-step methods. In the natural world, TiO 2 exists in three different crystalline forms as anatase, brookite, and rutile. Nanoparticles are not used directly in many heat transfer applications, and this provides a major challenge to researchers to advance towards stable nanofluid preparation methods. The primary step involved in the preparation of nanofluid is the production of nano-sized solid particles by using a suitable technique, and then these particles are dispersed into base fluids like oil, water, paraffin oil or ethylene glycol. However, nanofluid can also be prepared directly by using a liquid chemical method or vapor deposition technique (VDT). Nanofluids are mostly used in heat transfer applications and the size and cost of the heat transfer device depend upon the working fluid properties, thus, in the past decade scientists have made great efforts to formulate stable and cost-effective nanofluids with enhanced thermophysical properties. This review focuses on the different synthesis techniques and important physical properties (thermal conductivity and viscosity) that need to be considered very carefully during the preparation of TiO 2 nanofluids for desired applications.
Titanium dioxide (TiO 2) has been used extensively because of its unique thermal and electric pro... more Titanium dioxide (TiO 2) has been used extensively because of its unique thermal and electric properties. Different techniques have been used for the preparation of TiO 2 nanofluids which include single-step and two-step methods. In the natural world, TiO 2 exists in three different crystalline forms as anatase, brookite, and rutile. Nanoparticles are not used directly in many heat transfer applications, and this provides a major challenge to researchers to advance towards stable nanofluid preparation methods. The primary step involved in the preparation of nanofluid is the production of nano-sized solid particles by using a suitable technique, and then these particles are dispersed into base fluids like oil, water, paraffin oil or ethylene glycol. However, nanofluid can also be prepared directly by using a liquid chemical method or vapor deposition technique (VDT). Nanofluids are mostly used in heat transfer applications and the size and cost of the heat transfer device depend upon the working fluid properties, thus, in the past decade scientists have made great efforts to formulate stable and cost-effective nanofluids with enhanced thermophysical properties. This review focuses on the different synthesis techniques and important physical properties (thermal conductivity and viscosity) that need to be considered very carefully during the preparation of TiO 2 nanofluids for desired applications.
Conference Presentations by HAMZA BABAR
HYBRID NANOFLUIDS: TECHNIQUES AND CHALLENGES OF STABILITY ENHANCEMENT, 2018
To date, enormous evaluative work has been conducted on hybrid-nanofluids to explore their heat t... more To date, enormous evaluative work has been conducted on hybrid-nanofluids to explore their heat transfer and physical features. Brief summary of the findings of most recent studies is presented in this review. Pivotal analysis of past studies revealed that hybrid nanofluids are highly effective heat transfer media owing to their elevated thermal and physical characteristics. But the sole issue associated with these fluids is their instability. Short stability lasting period of hybrid-nanofluid has faded the feasibility of their commercial use despite of tempting features like elevated thermal and rheological characteristics. Some of the known ways of stabilizing these fluids include sonication, addition of dispersant, and controlling their pH value. Comprehensive details of aforementioned techniques along with associated challenges as well as stability determining methods such as Zeta-potential, sedimentation period, spectral absorption, and centrifugation, have been presented in this review. Controlling the nanoparticle size, concentration, and rheological aspects leads to better stability. Considering the thermal features and stability period, potential of different hybrid-nanofluids for future work has been discussed in the concluding section of this paper.
Books by HAMZA BABAR
Application of Nanofluids for Thermal Management of Photovoltaic Modules: A Review, 2018
Mounting temperature impedes the conversion efficiency of photovoltaic systems. Studies have show... more Mounting temperature impedes the conversion efficiency of photovoltaic systems. Studies have shown drastic efficiency escalation of PV modules, if cooled by nanofluids. Ability of nanofluids to supplement the efficiency improvement of PV cells has sought attention of researchers. This chapter presents the magnitude of improved efficiency found by different researchers due to the cooling via nanofluids. The effect of factors (such as, nanoparticle size, nanofluid concentration, flowrate of nanofluid and geometry of channel containing nanofluid) influencing the efficiency of PV systems has been discussed. Collective results of different researchers indicate that the efficiency of the PV/T systems (using nanofluids as coolant) increases with increasing flowrate. Efficiency of these systems increases with increasing concentration of nanofluid up to a certain amount, but as the concentration gets above this certain value, the efficiency tends to decline due to agglomeration/clustering of nanoparticles. Pertaining to the most recent studies, stability of nanoparticles is still the major unresolved issue, hindering the commercial scale application of nanofluids for the cooling of PV panels. Eventually, the environmental and economic advantages of these systems are presented.
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Papers by HAMZA BABAR
Conference Presentations by HAMZA BABAR
Books by HAMZA BABAR