variavel0=<b>Luis E.M. Souto</b> - souto@nrva.ufsc.br Universidade Federal de Santa Catarina
<b>Cesar J. Deschamps</b> - deschamps@nrva.ufsc.br Universidade Federal de Santa Catarina
<b>Abstract.</b> The work considers an experimental investigation of the turbulent flow through radial diffusers. The understanding of this class of flow is important in a number of technological applications and has attracted the interest of several researchers. Analytical solutions are restricted to idealized conditions and, therefore, numerical modeling is the most adopted technique to investigate the phenomenon. Experimental investigations are less common and usually offer only data for the resulting force (or the respective pressure distribution) on the front disk. The present work investigates the turbulent flow in radial diffuser for both stationary and transient conditions. The transient corresponds to a pulsating flow condition established through a proportional control valve, but keeping the gap between the disks fixed. Pressure distribution on the frontal disk is examined to detect any eventual effect that this pulsating flow condition might have on the flow. Results for these two flow conditions show a very small change on the pressure distribution caused by the pulsation. However, the data suggest that such effect may become significant as the gap between the disks is increased or the diameter ratio between the front disk and the feeding orifice is decreased. Experimental data for mean velocity and turbulent normal stress are obtained for the exit cross section of the diffuser and indicate a laminarization process along the diffuser walls.
<b>Keywords.</b> radial diffuser, turbulent flow, automatic valves, compressor valves.