عنوان مقاله [English]
In the present study a three-dimensional simulation of shell and tube heat exchanger has been studied under turbulent conditions using computational fluid dynamics. Initially the shell side fluid was pure water and in the next step 〖Al〗_2 O_3/Water nanofluids was considered. Then, performance of the heat exchanger, was compared in two states. There are about 1100000 cells at each heat exchanger. To simulate the thermal and rheological behavior of nanofluids, the C programming language was used in a user defined function tab.The results show that the use of nanofluids increases heat transfer rate about 9% and reduces the velocity in the shell side compared with the pure water base fluid. A theoretical model and two experimental models to estimate the viscosity of nanofluids were compared with each other. The results showed that in low concentrations of nanoparticles, the models are compatible with each other.