New Improved Method for Heat Transfer Calculation Inside Rough Pipes

An improved method for heat transfer calculations inside rough tubes is provided. The model has been obtained from a second assessment developed early by the authors on fluid flow in single-phase inside rough tubes. The proposed correlation has been verified by comparison with a total of 1666 experimental available data of 34 different Newtonian fluids, including air, gases, water and organic liquids. The proposed model covers a validity range for Prandtl number ranging from 0.65 to 4.52x10(4), values of Reynolds number from 2.4 x 10(3) to 822 x 10(6), a range of relative roughness ranging from 5 x 10(-2) to 2 x 10(-6), and viscosity ratio from 0.0048 to 181.5. The proposed model provides a good correlation for 2.4 x 10(3) <= Re < 10(4) and 10(4) <= Re < 8.32 x 10(6), with an average error of 18.3% for 70.4% of the data and 16.6% for 74.8% of the data, respectively. The method presents a satisfactory agreement with the experimental data in each interval evaluated; therefore, the model can be considered accurate enough for practical applications. At the present time, a method with similar characteristics is unknown in the available technical literature.

Automated summary

An improved method for heat transfer calculations inside rough tubes has been proposed and verified with a wide range of experimental data. The model shows good correlation within specified ranges of parameters, making it accurate and reliable for practical applications. No similar method with comparable characteristics is currently available in technical literature.