Mechanical Engineering, Fluid Flow and Transfer Processes, Energy Engineering and Power Technology, Energy
7
Scopus Publications
Scopus Publications
Experimental Study on MWCNT–Graphene/Water Hybrid Nanofluids Preparation, Characterization, Thermophysical Characteristics, and Rheology for Heat Transfer Azharuddin, Prashant Saini ASME Journal of Heat and Mass Transfer, 2026 In many applications, conventional process fluids are insufficient to achieve high-intensity heat transfer. Hybrid nanofluids (HNFs) are advanced heat transfer fluids primarily utilized for thermal energy transportation in various applications. This study aims to characterize multiwalled carbon nanotube (MWCNT) and graphene nanoparticles with scanning electron microscopy (SEM), X-ray Diffraction (XRD), and Fourier Transform Infrared using instrument QUANTA 450, Rigaku Ultima IV, and SHIMADZU IRSprit, respectively. Different concentrations of HNFs were prepared consisting of MWCNT and graphene in water. The two-step technique employed for HNFs preparation involves stirring and sonication. Moreover, ultraviolet (UV) spectroscopy and particle size analysis (PSA) are used to characterize HNFs. Furthermore, the thermal and physical properties of HNFs are examined by experimental methods, covering a temperature range of 25 °C–75 °C. The investigational results demonstrate that the thermal conductivity improves by 32.87% for 0.03 vol. %, as temperature rises to 75 °C, when compared to water. Specific heat rises with temperature, while it reduces with nanoparticles' loading. The HNF's dynamic viscosity decreases with an increase in temperature. Density improves with the addition of nanoparticles. Rheology shows Newtonian behavior across the entire range of shear rates. Prepared HNFs are commended as a medium for heat transfer in numerous fields.
ENHANCING THERMODYNAMIC PERFORMANCE OF HEAT EXCHANGER USING AQUEOUS MWCNT-GRAPHENE HYBRID NANOFLUID: AN EXPERIMENTAL STUDY ON VARYING CONCENTRATIONS Azharuddin, Prashant Saini Journal of Enhanced Heat Transfer, 2025 In recent years, significant work has been carried out on hybrid nanofluids, which are supposed to be the next generation heat transfer fluid because they have better thermophysical properties. This study involves the characterization and dispersion of nanoparticles (multi walled carbon nanotube &#91;MWCNT&#93; and graphene) in H<sub>2</sub>O (1:1 mass ratio) to prepare hybrid nanofluid (HNF) at different concentrations (0.01 vol&#37; to 0.03 vol&#37;) by a two-step method. This experimental study was conducted to examine the impact of flow rate (115 lph to 155 lph) on heat transfers, energy efficiency, and exergy efficiency in a shell and tube heat exchanger using MWCNT-graphene/H<sub>2</sub>O as a working fluid. In addition, this study also investigates significant dimensionless numbers such as Reynolds (Re), Prandtl (Pr), and Nusselt number (Nu), as well as friction factor (F<sub>f</sub>), pressure drop, and thermal performance factor (TPF). The results reveal that actual, average, overall heat transfer, &eta;<sub>en</sub>, and &eta;<sub>ex</sub> of HNFs are 10.23&#37;, 14.49&#37;, 17.47&#37;, 10.26&#37;, and 9.12&#37; greater on the shell side compared to H<sub>2</sub>O at a mean flow rate (135 lph). On the tube side, these values are 19.97&#37;, 23.94&#37;, 34.28&#37;, 20.00&#37;, and 60.35&#37; higher than H<sub>2</sub>O. The convective heat transfer on tube side is 33.95&#37; higher than shell side. The shell side experiences a decrease in log mean temperature difference (LMTD) of 2.52&#37;, while the tube side has a decrease of 7.64&#37; compared to the H<sub>2</sub>O. A decrease in the F<sub>f</sub> leads to an increase in pressure drop. The TPF for HNFs is more than one, suggesting that prepared HNFs offer advantages in enhancing the overall performance of a shell and tube heat exchanger.
Energy, exergy and economic assessments of novel sustainable solar powered evacuated tube collector integrated active desalination system Angesh Kumar Shukla, Prashant Saini, Azharuddi, Vijay Kumar Dwivedi Desalination and Water Treatment, 2023 Novel sustainable solar powered combined desalination and hot water system is investigated based on energy, exergy and economic performances experimentally. For the purpose, evacuated tube collector integrated serpentine based active desalination unit is fabricated to fulfil the potable water and hot water supply especially in hospitals, hill station buildings and remote locations. Experimental investigations are performed for various mass flow rates in serpentine at different basin water depth (0.03, 0.04 and 0.05 m) over nine typical days. Effect of solar insolation and atmosphere temperature on potable water yield and system energy and exergy efficiencies are analyzed under real weather conditions. Measurements reveal that, maximum daily potable water yield, energy efficiency, exergy efficiency and hot water temperature are obtained as 5.10 kg/m 2 ·day, 42.39%, 4.45% and 67°C, respectively at 0.03 m water depth and lower mass flow rate. Additionally, potable water cost per litre (CPL) found minimum as 0.04073 $/L/m 2 for 25 y of operating life of system.
Thermodynamic Analyses of Shell and Tube Heat Exchanger Using Different Hybrid Nanofluid MWCNT-graphene/Water Concentrations Prashant Azharuddin, Jeeoot Singh, Khurshed Rashid, Ram Tripathi, Shahid Jamal, et al. Nanoworld Journal, 2023 Azharuddin, Prashant Saini, Jeeoot Singh, Mohd Khurshed Rashid, Ram Ji Tripathi and Shahid Jamal Current research involves investigating the heat transfer and thermal performances of a STHE utilizing MWCNT-Graphene/water HNF concentrations experimentally. MWCNT-Graphene nanoparticles are mixed with water (base fluid) to create different HNF test samples.
