Effect of Al2O3 nanoparticles on the performance of passive double slope solar still

Recently, the suspension of hybrid nanoparticles in conventional fluids has been investigated as a technique for improving the thermophysical properties of nanofluids. The dearth of documentation on the trio influence of volume concentration, base fluid, and temperature on the electrical conductivity and viscosity of hybrid alumina–ferrofluids [Al2O3–Fe2O3 (25:75 mass%)] has led to this study. The effective viscosity and electrical conductivity of the deionized water (DW)-based and ethylene glycol (EG)–DW-based (50:50 vol%) hybrid alumina–ferrofluids were measured at temperatures of 20–50 °C and volume concentrations of 0.05–0.75%. Based on the importance of soft computing methods to engineers, adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) were used for predicting the relative viscosity and electrical conductivity of the two types of hybrid ferrofluids. The measured data for viscosity and electrical conductivity were used in the modeling. Model performances were evaluated using the root mean squared error index. Viscosity was enhanced by 3.23–43.64% and 2.79–49.38%, while electrical conductivity was increased by 163.37–1692.16% and 717.14–7618.89% for the DW- and EG–DIW-based hybrid ferrofluids, respectively, compared with the respective base fluids. Increasing volume concentration augmented the viscosity and electrical conductivity of all the hybrid alumina–ferrofluids, whereas a rise in temperature enhanced their electrical conductivity and detracted the viscosity. DW-based hybrid alumina–ferrofluid was observed to have a lower viscosity and higher electrical conductivity than the EG–DW-based counterpart. The results showed that the optimum ANN and ANFIS models have a maximum error of less than 4.5% and 3.9% for relative viscosity and electrical conductivity, respectively, which were lower than those proposed using regression analysis. With the hybrid alumina–ferrofluids possessing a lower viscosity relative to single-particle ferrofluids, they are recommended for engineering application.

Influence of base fluid, temperature, and concentration on the thermophysical properties of hybrid nanofluids of alumina–ferrofluid: experimental data, modeling through enhanced ANN, ANFIS, and curve fitting

Effect of nanofluids on the performance of passive double slope solar still: a comparative study using characteristic curve.

https://repository.up.ac.za/bitstream/handle/2263/21537/Meyer_Influence(2013).pdf;sequence=1

The influence of multi-walled carbon nanotubes on single-phase heat transfer and pressure drop characteristics in the transitional flow regime of smooth tubes

Exergoeconomic and enviroeconomic analyses of hybrid double slope solar still loaded with nanofluids

In this communication, simple formulas (based on the latest experimental tabulated data) for 11 physical properties of liquid ordinary water substance at saturation state—saturation pressure, density, volumetric thermal expansion coefficient, specific volume of saturated vapor, specific enthalpy, specific heal, latent heal of vaporization, thermal conductivity, dynamic viscosity, Prandtl number, and surface tension as a function of temperature (from 0 to 150°C)—which are used in heat transfer calculations for heat exchangers in heating systems and also for many other technological applications, are presented. Also, the uncertainties of these formulas are given. In most practical cases the pressure of liquid water is within the range from 1 to 10 absolute bar, which makes it possible to neglect the effect of pressure. All properties of saturated liquid water calculated with the recommended formulas are tabulated with a temperature increment of 5°.

C. O. Popiel

Papers

Simple Formulas for Thermophysical Properties of Liquid Water for Heat Transfer Calculations (from 0°C to 150°C)