Abstract:
In the presented experimental study, twelve different double-sided curved blade vortex generators were produced at two blade angles (15° and 30°) based on the turbulator blade angle, blade direction, and the placement of the turbulators in the pipe. After conducting smooth pipe studies, the curved structure's winglet components were mounted on the pipe at various angles and locations, and the effects on heat transfer and pressure drop were determined for Reynolds Numbers ranging from 16,210 to 41,470. The smooth pipe results obtained were compared with the results obtained from the numerical Gnielinski, Dittus-Boelter, Blasius, and Petukhov equations. In addition, a control circuit has been developed to ensure the precision and recording reliability of the results. The root mean square error (RMSE) and mean absolute percent error (MAPE) results obtained by the controller circuit were found to be in good agreement with the results of the experimental study. Considering the results obtained with the elements placed in the pipe, the highest increases in Nusselt number and friction factor compared to the smooth pipe were 173% and 592%, respectively. The most notable Nusselt number (Nua/Nuo) and friction factor (fa/fo) increases were seen in the values of 3.41 and 6.92, respectively. The highest PEC value for the heat transfer improvement effect was approximately 1.79 for the low Reynolds Number value of 16,214. Among all the turbulators, the highest heat transfer increase was achieved with the double-sided opened blade (UD-30) type turbulator, while the lowest heat transfer increase effect was achieved with the one-bladed opened type (OC-15) turbulator. In terms of PEC, eight turbulators had a significant effect on all Reynolds values, but the remaining four had no effect. © 2022 Elsevier Masson SAS