Experimental investigation of performance improvement of double-pipe heat exchangers with novel perforated elliptic turbulators

In the present study, heat transfer and thermal efficiency of double-pipe exchangers with novel Double-Perforated Inclined Elliptic (DPIE) turbulators were experimentally investigated. The range Reynolds number was between 5000 18,000 under turbulent flow regime. inclination angle elliptic inserts (?), perforation diameters (d) varied from 15° to 25°, 0.5 mm < d 1.5 mm, respectively. perforated vortex generators can significantly increase perturbations disrupt boundary layer enhance without noticeable impact on friction loss. experiments revealed that average Nusselt increased by 217.4% using DPIE compared tube generators. recirculations through perforations turbulators, fluid mixing walls core area. maximum parameter 1.849 obtained for d/b = 0.25 ?=25?. Friction factor increment 14.0% observed double typical perforations. It found is around 39.4% louvered strips main benefits proposed are their much higher previous at wide numbers, simple installation together low manufacturing costs.