a numerical investigation of γ-al2o3-water nanofluids heat transfer and pressure drop in a shell and tube heat exchanger

the effect of γ-al2o3 nanoparticles on heat transfer rate, baffle spacing and pressure drop in the shell side of small shell and tube heat exchangers was investigated numerically under turbulent regime. γ-al2o3-water nanofluids and pure water were used in the shell side and the tube side of heat exchangers, respectively. since the properties of γ-al2o3-water nanofluids were variable, they were defined using the user define function. the results revealed that heat transfer and pressure drop were increased with mass flow rate as well as baffle numbers. adding nanoparticles to the based fluid did not have a significant effect on pressure drop in the shell side. the best heat transfer performance of heat exchangers was for γ-al2o3-water 1 vol.% and higher nanoparticles concentration was not suitable. the suitable baffle spacing was 43.4% of the shell diameter, showing a good agreement with bell-delaware method.