Heat transfer and pressure drop in tubes with short turbulators

The results of investigations concerning heat transfer and pressure drop in a tube with short single-turn turbulators in form of a twisted tape are presented here. The experiments were carried out in the range: 1300 less than or equal to Re less than or equal to 8000 4,3 less than or equal to Pr less than or equal to 7,0, 2,9 less than or equal to S/d less than or equal to 4,4 with water as the test fluid. The results were compared with those obtained when investigating heat transfer and flow resistance in a tube with a turbulator installed all along the tube. It was demonstrated that in certain conditions, assuming that Q = idem, F = idem and S = idem, the power demand for pumping medium can be reduced.