This paper presents results of a numerical study of mixed convection and entropy generation of Cu–water nanofluid in a square ventilating cavity at different inclination angles. Except a piece of bottom wall with a uniform heat flux, all of the cavity walls are insulated. The inlet port is placed at the bottom of the left wall and the outlet port is positioned at the top of the right wall. Entropy generation, Bejan number, average Nusselt number and heat source temperature have been investigated for Richardson numbers between 0.1 and 10, Reynolds numbers in the range of 1 and 300, solid volume fractions between 0 and 0.06 and cavity inclination angles between -900 and 900. The results show that the average Nusselt number increases withincreasing Richardson number for cavity inclination angle of 300, 600 and 900 but decreases with increasing Richardson number for inclination angle of -300, -600 and -900. Total entropy generation and entropy generation due to heat transfer decreases with increasing Richardson and Reynolds numbers, but the Bejan number increases with increasing Reynolds and Richardson numbers.

Objective(s): Acinetobacter baumannii is crucial for healthcare-associated diseases by significant local variations in the resistance scale, but its risk factors and infection courses have not been adequately studied. Carbon nanotubes are substantially circular molecules made entirely from carbon atoms and can use as nanocarriers. Through their unique characteristics, multi-wall carbon nanotubes hold great promise in the fight against multidrug-resistant bacterial infections. In this research, antimicrobial effects study and the ability to overcome antibiotic resistance evaluation of nanofluid containing functionalized carbon nanotubes on A. baumannii were done. Methods: Multi-wall carbon nanotubes provided from the United States Research and the nanofluid prepared after carbon nanotube functionalization. Microplate, Alamar Blue Cell viability assay, carried out after incubation of A. baumannii affected with the nanofluid (100μ g/ml) for 24h. Results: Antimicrobial effect of functionalized carbon nanotubes nanofluid was found on the A. baumannii in a dose-specific concentration manner Conclusions: This study showed that functionalized carbon nanotubes nanofluid could have antimicrobial effects on A. baumannii by overcoming bacterial antibiotic resistance. Although to get more accurate results, to prevent nosocomial infections, more specific cellular and molecular studies are necessary.

The aim of this paper is to analyze the problem of magneto hydrodynamic Jeffrey-Hamel flow (JHF) with nanoparticles. The governing equations for this problem are reduced to an ordinary differential equation and it is solved using new analytical method (NAM) and fourth-order Runge-Kutta Method (RK ∼ 4). The NAM is an iterative method that relies mainly on derivatives with Taylor expansion interference. In addition, the velocity profile has been computed and shown for various values of physical parameters. The objective of the present work is to investigate the effect of the angles between the plates, Reynold number, magnetic number and nanoparticles volume fraction on the velocity profile.

The main purpose of this study is to perform numerical simulation of nanofluids as the coolant in VVER-440 fuel rod bundle. The fuel rod bundle contains 60 fuel rods with length of 960 mm and 4 spacer grids. In VVER-440 fuel rod bundle the coolant fluid (water) is in high pressure and temperature condition. In the present Thermo-hydraulic simulation, water-AL2O3 nanofluids containing various volume fractions of AL2O3 nanoparticles are investigated. Calculations performed for Reynolds number of 125000 to 203000, nanoparticles fraction of 0 to 0.05 and nanoparticles diameter of 20 to 100 nm. In this literature, the effects of diameter and volume fraction of nanoparticles on thermo-hydraulic parameters are studied. To perform correct calculation, different grid qualities of fuel rod bundle are studied and results are compared with reference results. Empirical studies show that as the temperature rises, the effect of nanoparticles on enhancing thermal conductivity intensifies. So it can be said that as the VVER-440 fuel rod bundle works in high temperature condition, using the nanofluids in this rod bundle can be effective. Results of our numerical study showed that by using nanofluids as coolant fluid the heat transfer coefficient increases significantly and heat transfer enhancement raises with increase in volume fraction of nanoparticle.

This work focuses on the dynamical behavior of carbon nanotubes, including vibration, wave propagation and fluid-structure interaction. In the present research, transverse vibration of nano fluid conveying carbon nanotubes is investigated. To this end, based on the nonlocal and strain-inertia gradient continuum elasticity theories and by using rod and Euler-Bernoulli beam models, the system’s dynamical behavior is modeled and then, the governing equation of motion is solved and discretized by applying the weighted-residual Galerkin approximate method. Moreover, effect of considering nano-scale fluid flowing through the nanotube, the boundary conditions, the different elastic mediums and the van der Walls interaction between the layers of multi-walled carbon nanotubes on the natural frequencies, critical velocities and stability of the system are considered. The results show that the passing fluid flow and the axially moving of nanotube decrease the system’s natural frequencies especially for nanotubes with large internal radius and in high fluid flow and axially moving speeds of nanotube. In addition, it is observed that the natural frequencies and stability of the system strongly depend on the small-scale parameter (nano-scale), mainly in the longitudinal vibration.

A nanofluid is mixture of nano sized particles and a base fluid. This paper investigates by using laboratory based double pipe heat exchanger model, the performance of nanofluid containing about 48.46nm particle size nanoparticles (ZnO) without or with addition of nonionic surfactant Rokanol K7 (500ppm) into the base fluid double distilled water to prepared three different concentrations 1.0%, 2% and 3% (v/v) of ZnO water or ZnO-RK7. Effects of temperature and concentration of nanoparticles on viscosity and heat transfer coefficient in heat exchanger are investigated. The experimental results shows that the viscosity of nanofluids increased with increasing concentration of fluid whereas decreased with increasing temperature from 20 to 60ºC. However, it has been also observed that heat transfer coefficient increases with the operating temperature and concentration of nanoparticles. The conclusion derived for the study is that overall heat transfer coefficient enhanced with increasing concentration upto 3% of ZnO-RK7 as compared to without surfactant nanofluids.

SKD 11 tool steel is among the most popular metals in mold industries for making different kinds of cold work molds and dies with high accuracy and long service life. The demand for higher quality, lower manufacturing costs, particularly the environmentally friendly characteristics, have provided the stimuli for manufacturers and researchers to find alternative solutions. An excellent media is formed in the cutting zone by using MQL nanofluids in order to enhance the thermal conductivity and tribological characteristics; therefore, improving the machining performance. The formation of the lubricating film as well as the rolling action of nanoparticles in contact zones has gained much attention in the machining field. In this research work, the application of MQL Al2O3 nanofluids with vegetable oils and emulsion 5% is developed for slotting end milling of SKD 11 steel using normal HSS tool. The cutting forces, tool wear, tool life, and surface roughness are investigated to evaluate the effectiveness of MQL nanofluid on cutting performance. The experimental results reveal that the cutting forces and cutting temperature decrease and the surface quality and tool life enhance. Furthermore, the improvement of the thermal conductivity of nanofluids is proven when compared to pure fluids. Due to the rise of viscosity and thermal conductivity, the soybean oil-based nanofluid, which is almost inherently nontoxic, gives superior lubricating and cooling properties suitable for MQL application compared to emulsion-based nanofluids. The novel environmental friendly technology definitely brings out many technological and economic benefits in machining practice.