Specific Heat Capacity Of Nanofluids Research Articles

A Review on the Viscous and Thermal Transport Properties of Nanofluids

In modern science and engineering nanofluids are playing a vital role in the application of heat transfer devices due to their effective properties. Addition of nanoparticles in the fluid can alter thermophysical properties of the nanofluid. Experimental and theoretical studies are essential to understand the change in fluid dynamics aspects of the fluid by the addition of nanoparticles. This paper presents a brief review on the viscous and thermal transport effects of nanofluids. The main emphasis is on the comparison of previous theoretical and experimental studies for thermophysical properties of nanofluids. These properties include density, viscosity, thermal conductivity and specific heat capacity of nanofluids.

A phonon thermodynamics approach of gold nanofluids synthesized in solution plasma

The phonon thermodynamics theory for liquids was applied to explain the thermal characteristics of gold nanofluids synthesized by a simple, one-step, and chemical-free method using an electrical discharge in a liquid environment termed solution plasma process. The specific heat capacity of nanofluids was measured with a differential scanning calorimeter using the ratio between the differential heat flow rate and the heating rate. The decrease of the specific heat capacity with 10% of gold nanofluids relative to water was explained by the decrease of Frenkel relaxation time with 22%, considering a solid-like state model of liquids.

Study of viscosity and specific heat capacity characteristics of water-based Al2O3 nanofluids at low particle concentrations

In this paper, the specific heat capacity and viscosity properties of water-based nanofluids containing alumina nanoparticles of 47 nm average particle diameter at low concentrations are studied. Nanofluids were prepared with deionised water as base fluid at room temperature by adding nanoparticles at low volume concentration in the range of 0.01%–1% to measure viscosity. The effect of temperature on viscosity of the nanofluid was determined based on the experiments conducted in the temperature range of 25°C to 45°C. The results indicate a nonlinear increase of viscosity with particle concentration due to aggregation of particles. The estimated specific heat capacity of the nanofluid decreased with increase of particle concentration due to increase in thermal diffusivity. Generalised regression equations for estimating the viscosity and specific heat capacity of nanofluids for a particular range of particle concentration, particle diameter and temperature are established.

Thermal and rheological characteristics of CuO–Base oil nanofluid flow inside a circular tube

In the present experimental investigation, stable CuO–Base oil nanofluids with different particle weight fractions of 0.2% to 2% are prepared. Then, these fluids are used for heat transfer measurements as well as rheological behavior investigation. Density, thermal conductivities, viscosities and specific heat capacities of base fluid and all nanofluids at different temperatures are measured and the effect of nanoparticles concentration on fluid properties is investigated. Also, heat transfer characteristics of CuO–Base oil nanofluids laminar flow in a smooth tube under constant heat flux are studied experimentally. Experimental results clearly indicate that addition of nanoparticles into the base fluid enhances the thermal conductivity of the fluid and the enhancement increases with increasing of particle concentration. For the particle concentrations tested, nanofluids exhibit Newtonian behavior. It is observed that the dynamic viscosity substantially increases with the increase in nanoparticle concentration and this increase is more pronounced at the lower temperatures of the nanofluid. The specific heat capacity of nanofluids is significantly less than that of base fluid and it is decreased with the increase in nanofluid concentration. The results show that for a specific nanoparticle concentration, there is an increase in heat transfer coefficient of nanofluid flow compared to pure oil flow. A maximum increase of 12.7% in Heat Transfer coefficient was observed for 2 wt.% nanofluid at the highest Reynolds number studied in this investigation. Furthermore, heat transfer coefficients obtained using experimental fluid properties are compared to those obtained using the existing theoretical models for fluid properties.

Enhancement of specific heat capacity of high-temperature silica-nanofluids synthesized in alkali chloride salt eutectics for solar thermal-energy storage applications

In this study, we report the anomalous enhancement of specific heat capacity of high-temperature nanofluids. Alkali metal chloride salt eutectics were doped with silica nanoparticles at 1% mass concentration. The specific heat capacity of the nanofluid was enhanced by 14.5%. Dispersion behavior of the nanoparticles in the eutectic was confirmed by scanning electron microscopy (SEM). Three independent competing transport mechanisms are enumerated to explain this anomalous behavior.