Heat transfer augmentation for turbulent flow in circular tubes using inserts with multiple curved vortex generator elements

• Published in: International journal of thermal sciences 2022-01, Vol.171, p.107203, Article 107203
• Main Authors: Deshmukh, Prashant Wasudeo, Prabhu, Siddini Venkatesh, Vedula, Rajendra Prasad
• Format: Article
• Language: English
• Subjects: Curved delta wing; Heat transfer enhancement; Local measurements; Thermo-hydraulic performance; Vortex generator insert
• ISSN: 1290-0729; 1778-4166
• DOI: 10.1016/j.ijthermalsci.2021.107203

Measurements of local heat transfer coefficients on the circumference of a circular tube, fitted with two modified versions of an already existing axially inline curved Vortex Generator (VG) element insert are reported in this study. Measurements for average pressure drop are also presented and the air was used as the working fluid. The first modified insert is manufactured with a pair of two VG elements spaced symmetrically 180° apart but with the subsequent pairs along the axis staggered at an angle of 90°. The geometric features for the staggered insert were identical to the optimal one for the existing inline one. The staggered insert gives a more uniform circumferential and axial Nusselt number distribution. The ratio of the highest and lowest Nusselt number values for the staggered and inline case is equal to approximately 1.3 and 1.6 respectively. The average Nusselt number ratio at constant Reynolds number (10,000