Natural Heat Transfer from Finned Heat Exchanger Fixed in Variable Diverge Duct

EasyChair Preprint no. 8509

Abstract

In the present work, an experimental study of natural heat transfer from heated cylinders fixed in variable shape (diverge air duct) made from Pyrex glass. Two finned cylinders made from mild iron, outer diameter12mm, inner diameter10 mm, rectangle fins dimensions 70 x 40 mm. The angle of the two walls of the duct was changed to six angles α: 0°, 3°, 5°,7°,10°, and 15° with the vertical to make diverge shape. The cylinders were fixed inside the duct at top, center, and bottom in three locations. The cylinders were heated by the supply of variable power of constant heat flux 88,177, 390, and 680 w/ m2. The study was done with Rayleigh numbers (15x104to 12 x103). the heat was carried by free convection by atmosphere air. The results of experimental found that, for top location, the value of Nusselt number decrease by 15 % at ԛ•= 88 W/ m2 when increase the value of angle from 0° to 3°, and decreased by 25 % at ԛ•= 680 W/ m2 when increase the value of angle from 0° to 10°. For center location, the value of Nusselt number decrease by 21.6 % at ԛ•= 88 W/ m2 when increase the value of angle from 0° to 3°, and decrease by 13.7 % at ԛ•= 680 W/ m2 when increase the value of angle from 0° to 10°. For bottom location, the value of Nusselt number decrease by 50 % at ԛ•= 88 W/ m2 when increase the value of angle from 0° to 5°, and decrease by 21 % at ԛ•= 680 W/ m2 when increasing the value of angle from 0° to 15°.The best location for the heat exchanger was at the bottom, and the best angle was 0°.

Keyphrases: Diverge, Heat convection, Natural convection, rectangle fins, two finned cylinder, variable air duct

@Booklet{EasyChair:8509,
  author = {Hassan K. Abdullah and Mohammed A. Hassan},
  title = {Natural Heat Transfer from Finned Heat Exchanger Fixed in Variable Diverge Duct},
  howpublished = {EasyChair Preprint no. 8509},

  year = {EasyChair, 2022}}