scholarly journals Performance of Heat Transfer and Friction Factor of Heat Exchanger with Al2o3/ Water Nano Fluids

This paper summary of heat transfer characteristics and nano fluids mechanics by using single phase convection techniques. Gas having less thermal conductivity compare than the liquids having high thermal conductivity. The heat transfer enhancement improved by using nano fluids Al2O3 compared with base water. The heat transfer enhancement was analysed with plain tube and twisted tape inserts with nano fluids. The experimental investigation was analysed and reading was taken to improve the heat transfer and friction flow characteristics. The Reynolds number varies from different ranges with plain water and Nano fluids. The experimental record of nano fluid heat transfer value was increased with 2.89 percentage compare with the experimental record of plain water. The nano fluids has more concentration than the plain water.

2015 ◽  
Vol 93 (7) ◽  
pp. 725-733 ◽  
Author(s):  
M. Ghalambaz ◽  
E. Izadpanahi ◽  
A. Noghrehabadi ◽  
A. Chamkha

The boundary layer heat and mass transfer of nanofluids over an isothermal stretching sheet is analyzed using a drift-flux model. The relative slip velocity between the nanoparticles and the base fluid is taken into account. The nanoparticles’ volume fractions at the surface of the sheet are considered to be adjusted passively. The thermal conductivity and the dynamic viscosity of the nanofluid are considered as functions of the local volume fraction of the nanoparticles. A non-dimensional parameter, heat transfer enhancement ratio, is introduced, which shows the alteration of the thermal convective coefficient of the nanofluid compared to the base fluid. The governing partial differential equations are reduced into a set of nonlinear ordinary differential equations using appropriate similarity transformations and then solved numerically using the fourth-order Runge–Kutta and Newton–Raphson methods along with the shooting technique. The effects of six non-dimensional parameters, namely, the Prandtl number of the base fluid Prbf, Lewis number Le, Brownian motion parameter Nb, thermophoresis parameter Nt, variable thermal conductivity parameter Nc and the variable viscosity parameter Nv, on the velocity, temperature, and concentration profiles as well as the reduced Nusselt number and the enhancement ratio are investigated. Finally, case studies for Al2O3 and Cu nanoparticles dispersed in water are performed. It is found that increases in the ambient values of the nanoparticles volume fraction cause decreases in both the dimensionless shear stress f″(0) and the reduced Nusselt number Nur. Furthermore, an augmentation of the ambient value of the volume fraction of nanoparticles results in an increase the heat transfer enhancement ratio hnf/hbf. Therefore, using nanoparticles produces heat transfer enhancement from the sheet.


Lab on a Chip ◽  
2014 ◽  
Vol 14 (17) ◽  
pp. 3419-3426 ◽  
Author(s):  
Pyshar Yi ◽  
Robiatun A. Awang ◽  
Wayne S. T. Rowe ◽  
Kourosh Kalantar-zadeh ◽  
Khashayar Khoshmanesh

This work introduces a method to enhance the thermal conductivity of PDMS microfluidic platforms through the use of PDMS/Al2O3 nanocomposites.


Sign in / Sign up

Export Citation Format

Share Document