Heat transfer and friction characteristics of fully developed gas flow in cross-corrugated tubes

This experimental study is concerned with gas-liquid heat exchangers relying on cross-corrugated tubes. The experiments are carried out with air flow on the inner side of the tube, cooled by a secondary outer water flow. Overall 18 different geometrical configurations are investigated. In contrast to Harleß et al. (2016) the emphasis of the present investigation is put on the cross-corrugated variant. The dimensionless corrugation pitch p/di varies between 0.283 and 1.117, the dimensionless corrugation height e/di between 0.024 and 0.087, and the corrugation angle φ between 14.7° and 48.8°. The examined Reynolds number range is 5000