As a result of analysis Miheev’s correlation equations for Nusselt number calculation in case of forced convection in pipes, with the help of multiply linear and non-linear regression and statistical analysis, new correlations are suggested. Using new correlations in heat transfer calculation, there is no need in iteration solver. The equations for transition flow regime were formulated. This makes it possible to take account of transition flow regime in heat transfer and hydraulic calculations.
A comparative analysis of the experimental values of the hydraulic resistance coefficient λ in the mixed friction turbulent mode zone (ZMF) with the values calculated by the most common calculation dependencies has been carried out. It is found that if the co-equivalent roughness is determined on the basis of the solution of the inverse problem, then any of these formulas can be used to calculate λ in the ZMF with an error acceptable for engineering calculations. To reduce the error of friction head hτ calculation using Leibenzon's formula, the approximation of Altshul's formula was performed, as a result of which new coefficients β and m for ZMF were calculated and the boundary Reynolds numbers for this zone were specified.
