This paper investigates the enhancement of heat transfer coefficient and Nusselt number of a nanofluid containing nanoparticles (γ-AL2O3) with a particle size of 20 nm and volume fraction of 0.1%-0.3% (V/V). Effects of temperature and concentration of nanoparticles on Nusselt number changes and heat transfer coefficient in a double pipe heat exchanger with counter turbulent flow are investigate...

Nanofluids are stable suspensions of nanoparticles in conventional heat transfer fluids (base fluids) that exhibit better thermal characteristics compared to those of the base fluids. It is important to clarify various aspects of nanofluids behavior. In order to identify the thermal and hydrodynamic behavior of nanofluids flowing through non-circular ducts, in the present study the laminar flow...

A numerical simulation model for laminar flow of nanofluids in a pipe with constant heat flux on the wall was built to study the effect of the Reynolds number on convective heat transfer and pressure loss. The investigation was performed for hybrid nanofluids consisting of CuO-Cu nanoparticles and compared with CuO and Cu in which the nanoparticles have a spherical shape with size 50, 50, 50nm ...

Nanofluids are a new class of thermal vectors potentially able to drastically increase the heat transfer properties of base fluids such as water, glycol and oil. Nanoparticles of various materials, size (<100 nm), shapes and concentrations can be added to the base fluid to enhance the transport properties. In particular, the knowledge of thermal conductivity and viscosity is essential to study ...

a nanofluid is a dilute liquid suspension of particles with at least one critical dimension smaller than ~100 nm. research works so far suggest that nanofluids offer excellent heat transfer enhancement over conventional base fluids. the enhancement depends on several factors such as particle shape, particle size distribution, volume fraction of nanoparticles, temperature, ph, and thermal conduc...

Nowadays, heat exchangers with twisted-tape inserts have widely been applied for enhancing the convective heat transfer in various industries such as thermal power plants, chemical processing plants, air conditioning equipment, refrigerators, petrochemical, biomedical and food processing plants. In general, twisted tape insert introduces swirl into the bulk flow which consequently disrupts a th...