Flow and mass transfer in a perturbed turbulent pipe flow

Flow and mass transfer phenomena in turbulent flow in a circular pipe containing a ring obstruction of rectangular cross section is studied. Mass transfer rates at the pipe wall in the separated flow region behind the obstruction are measured using the electrochemical technique (Schmidt number = 1670) within the Reynolds number range 10,000 to 100,000. Numerical computation using the TEACH computer code with the K-epsilon model of turbulence are also carried out for this flow configuration. Calculated rates of mass transfer are compared with the ones measured in the present work and show good agreement. Calculated flow behavior is compared with measurements existing in the literature. Calculations are also presented at lower Schmidt (or Prandtl) numbers showing the heat and mass transfer characteristics for other fluids of practical interest in perturbed pipe flows.