HYDRODYNAMICS AND MASS-TRANSFER IN DECAYING ANNULAR SWIRL FLOW

This paper reports an electrochemical study of local mass transfer beh aviour in decaying annular swirl flow. Initially, flow visualisation e xperiments were conducted to observe the general behaviour of the flow . It was found that the swirl angle decays exponentially along the tub e. Measurements of pressure drop across the vaned swirl generators wer e correlated in terms of the inverse of the square of the tangent of t he vane angle and approximately the square of the mean fluid velocity for vane angles of 30-degrees and over. Measurements of the axial dist ribution of local mass transfer coefficient for the inner rod were car ried out using the electrochemical limiting diffusion current techniqu e and results were correlated for each swirl generator, in the Reynold s number range 3300-50000. It was found that the relative enhancement of mass transfer in swirl flow increases as the vane angle increases a nd Reynolds number decreases.