Heat transfer enhancement by a sinusoidal wavy plate having punched triangular vortex generators

Abstract

The impact of punched triangular longitudinal vortex generators and sinusoidal wavy plates on convective heat transfer was investigated using a variety of approaches. The experiments were performed in a rectangular duct with flat plate-punched triangular vortex generators (PTVGs) and sinusoidal wavy plate-punched triangular vortex generators (SW-PTVGs) under different Re numbers (10,000, 20,000, 30,000, and 50,000), four different wave lengths (Lw) (40 mm, 50 mm, 60 mm, and 70 mm), attack angles of punched winglet (θ) (15°, 30°, 45°, and 75°) and a distance of punched winglet from the channel bottom (b) to winglet height (H) (b/H = 0.04, 0.08, 0.16, and 0.24). To reduce the number of trials, the Taguchi technique was utilized, thereby reducing the number of trials from 45 to 16. The highest thermal performance factor was determined as approximately 2.2 in Case 2, which was observed in Case 2 with b/H value of 0.08, Re = 10,000, θ = 30°, and Lw = 50 and fin-type 0°. The highest thermal performance factor achieved 2.2 as a result of the vortex generator, sinusoidal structure, and punched hole. The Re number, which is fairly high at 68.16%, has the most influence on the friction factor. The contribution rate of the Re number, which has the greatest effect on the Nu number, is 55%, which means that the Re number is highly effective for performance.