MASS TRANSFER IN TURBULENT PULSATING FLOWS

The effect of flow oscillation to the mass transfer between turbulent fluid and solid wall was investigatedby measuring the mass transfer rate between fluid and pipe wall with imposed oscillating flow usingelectrochemical method.The velocity and concentration field in the viscous sublayer which controls the mass trans-fer in such a process was simulated by a simple wave model of single harmonics.Experimental results confirmthat the flow oscillation has no influene on time averaged mass transfer rate,but the phase difference betweenphase averaged velocity field and concentration field shifts with the frequency of imposed oscillating flow.Numeri-cal analysis reveals that the concentration boundarylayer which is responsible for the mass transfer is muchthinner than the viscous sublayer which greatly weakens the influence of imposed oscillating flow on mass transfer.

MASS TRANSFER IN TURBULENT PULSATING FLOWS

The effect of flow oscillation to the mass transfer between turbulent fluid and solid wall was investigated by measuring the mass transfer rate between fluid and pipe wall with imposed oscillating flow using electrochemical method. The velocity and concentration field in the viscous sublayer which controls the mass transfer in such a process was simulated by a simple wave model of single harmonics. Experimental results confirm that the flow oscillation has no influence on time averaged mass transfer rate, but the phase difference between phase averaged velocity field and concentration field shifts with the frequency of imposed oscillating flow. Numerical analysis reveals that the concentration boundary layer which is responsible for the mass transfer is much thinner than the viscous sublayer which greatly weakens the influence of imposed oscillating flow on mass transfer.