Use of CFD code to calculate heat transfer coefficients in pipes with extended surface and turbulent promoters

Abstract

In this project, heat transfer and pressure drop performance of pipes with extended surface and different twisted tape inserts were simulated with ANSYS Fluent © software. The studied pipes were characterized by height and length of the surface crests and the twist of the twisted tape insert. After a superficial exploration of meshes and turbulence models for a single pipe, k-w SST model was chosen to make further. The results obtained with CFD were compared with experimental data to confirm the veracity of the simulations, which show a higher exactitude for temperature outlet compared to pressure drop. After that, it was seen how the geometric characteristics affect to heat transfer and pressure drop. Both heat transfer and pressure drop increase when the insert curvature and the crests size increase, in other words, when turbulence is promoted. Finally, the Thermal Performance Factor was calculated to see if the heat transfer enhancement was worth the pressure drop increase. The TPF showed a result >1, confirming that the performance of the modified pipes is better than a plain cylindrical pipe