MATHEMATICAL MODEL AND CALCULATION OF HEAT TRANSFER COEFFICIENTS OF ROUGH TURBULENT-FLOW-CARRYING CHANNELS

Semiempirical approaches to the determination of the average coeffi cients of heat transfer from rough surfaces of channels are considered. The expressions obtained on the basis of the boundary-layer models of Prandtl, Deissler, Hanratty, and von Kármán are given. The possibility of calculating the parameters of these expressions with account for the channel surface roughness is shown. A comparison of the results of calculations of Nusselt numbers for rough channels from the obtained formulas with calculations by the familiar formulas and with corresponding experimental data is made. A generalizing expression for rough channels has been obtained.
   
Author:  A. G. Laptev and M. M. Basharov
Keywords:  heat transfer, roughness, hydraulic resistance, boundary layer, turbulence
Page:  681