Experimental evaluation of performance intensification of double-pipe heat exchangers with rotary elliptical inserts

In this experimental work, heat transfer and thermal performance factor of double-pipe exchanger pipes with rotated inclined elliptical (RIE) inserts are examined. The rotation angle the turbulators (?), slant (?), perforation diameters (dp) were in range 0????90?, 15????25?, 0.5mm?dp?1.5mm, respectively. perforations can substantially intensify flow unsteadiness disturb boundary layer to improve without a perceptible effect on pressure drop. analysis showed that is improved up 30.7% by utilizing RIE comparison non-rotated elliptic (NRIE) turbulators. recirculating flows across rise fluid mixing amongst tube wall central region. highest 2.23 achieved for ?=90?, dp/b=0.250 ?=25?. obtained study noticeably higher than previous studies, increasing manufacturing costs. coefficient enhanced 59.95% NRIE vortex generators dp=1.5 mm typical louvered strips perforations.