Investigations on aligned pipe bundles pyramid-shaped roughened and smooth pipes

Automatic translation: Heat transfer coefficients and flow resistance coefficients are used reported on 5 tube bundles of different tube pitch and Pipe roughness was obtained. The investigations were carried out at Reynolds numbers between 4 * 10⁴ . . . .10⁶. Through the artificial Roughening the pipes resulted in an increase in the heat transfer coefficient of up to 50% compared to a pipe arrangement equal pitch and technically smooth pipes possible without This is the case with the aligned pipe arrangements examined would have been associated with an increase in flow resistance. In addition, the artificial roughening of the pipes caused a Evening out the speed profile behind the heat exchanger. The report also discusses pipe vibrations, observed during the experiments and in extreme cases led to the destruction of a heat exchanger The investigations were carried out within the framework of a cooperation agreement carried out with the Wieland-Werke in Ulm.