Experimental investigation of the mean and turbulent flow characteristics at the exit of automotive vented brake discs

The paper reports on an experimental investigation of the mean and turbulent flow structure at the exit of vented automotive brake discs. The main goal is to obtain a deeper insight of the aero-thermal phenomena upon which the brake efficiency strongly depends; a second important result is the generation of a comprehensive data set for CFD code validation. Two disc geometries were tested: a backward curved blade and a multiple pin configuration. The experiments were mainly focused on the evaluation of local and global fluid dynamic features, as vented mass flow rate and turbulence characteristics at the disc exit. Results in terms of mean and turbulence velocity component distributions and vented mass flow rate through the brake disc passages allow a comprehensive description of the flow behavior, together with a comparison between the two disc geometries. Once the mean and turbulent flow field at the disc exit was characterized, the effect of the presence of the caliper was investigated on both brake geometries. Effects on the total mass flow rate processed by the disc were evidenced as well as local distortion of the flow. A discussion of the caliper effects on the flow structure inside the channel, based on the measurements at the channel exit, is also reported.