MOMENTUM, HEAT, AND MASS-TRANSFER ANALOGY FOR DRAG-REDUCING SOLUTIONS

The new, generalized form of the analogy among momentum, heat, and mas s transfer for both Newtonian and drag-reducing solutions is presented . This work rests on the understanding that the shift in turbulent spe ctra due to the presence of additives must be taken into account becau se different portions of the turbulent spectra unequally affect the ra tes of momentum, heat, and mass transfer. These effects are accounted for through the turbulent Schmidt (Sc-t) or turbulent Prandtl (Pr-t) n umber in a manner analogous to the way that Sc (or Pr) number accounts for contributions of molecular transport. The proposed approach was v erified by (1) comparing the qualitative prediction for Sc-t number an d the calculated values from mass transfer data and (2) comparing pred icted and experimental data for heat transfer.