Question

A steel tube (k)of inner and outer diameters D, 24 mm and D, 30 mm, respectively, is used to transfer heat from hot gases flowing over the tube (h 250 ) to cold water flowing through the tube (h 9000) (a) An overall surface efficiency exists for both the hot surface h) and cold surface without any fins on the pipe, what are the values of oh and no.e? (b) Find the hot-side overall heat transfer coefficient Uh without fins. Also show U 298 m Note* (UrA) o you can define the overall heat transfer coeficient based on either surface, but then this surface. The final units on U are the same as h, U (e) To enhance heat transfer, 16 straight rectangular fins made of the same material are equally spaced around the ircumference of the tube. The t = 1 mm thick fins run down the entire pipe, and protrude from the surface a length L 10 mm. Determine the new Uh and Ue Compare how Un and Ue changes with the addition of the fins. Finally, compare (per unit length) the product UA with and without fins. Note* Fin Parameter → η, → ,h → Un

Please help with parts a, b, and c

Answer 1

Givn d.te o30 mm Outer Drection uid o Creu cohich Cold aig

he.t cieu 333.3311 예.cnd 다 wie fi-t ngn-l