A computational fluid dynamic analysis on the effect of front row pin geometry on the aerothermodynamic properties of a pin-vented brake disc

Abstract

Increasing demand from the consumer for higher levels of refinement from their passenger vehicles has put considerable pressure on the automotive industry to produce ever quieter cars. In order to prevent the occurrence of many forms of brake noise, especially judder and drone, excessive heating of the brake disc must be avoided, while minimizing temperature variations across the rotor. In order for this to be achieved the brake rotor must be designed such that it ensures sufficient uniform heat dissipation and thermal capacity. In high-demand braking applications, vented discs consisting of two rubbing surfaces separated by straight radial vanes are normally employed, as they utilize a greater surface area to dissipate heat. Within this paper the effects of changing the geometry of the first row of pins on aerothermodynamic properties of a pin-vented brake rotor are investigated using computational fluid dynamics (CFD). The validated CFD model shows that decreasing the thickness of the first row of pins by 10 per cent improves the mass flowrate through the rotor by 14 per cent and the heat transfer rate by 6 per cent. The results obtained can be used for the design of brake discs which are efficient with respect to heat dissipation.

An optimization study of a multiple-row pin-vented brake disc to promote brake cooling using computational fluid dynamics

“…CFD analysis of the baseline disc unearthed many interesting fluid dynamic phenomena which have been included in the previous paper [6]. Some of the key results from the initial analysis included the identification of the position of maximum and minimum values of static pressure to be on the high-pressure and suction side of the leading edge of the pins in the front row.…”

“…A full description of the validation has been included in the paper by Palmer et al [6]. It has been shown that the numerical simulations match experimental data favourably both qualitatively and quantitatively and can be used with confidence for further flow analysis.…”

“…The full details of the mathematical formulation can be found in the paper by Palmer et al [6]. For completeness, essential information is presented here.…”

“…Work by Qian [5] carried out on discs with straight radial vanes has shown that, by utilizing a parametric approach to find an optimized configuration, the average heat transfer coefficient of the brake disc could be improved by 35 per cent over a baseline design. Recently, Palmer et al [6] carried out detailed computational fluid dynamics (CFD) analysis of the flow through a pin-vented disc and optimized the first-row pin geometry for better cooling characteristics. They reported an improvement of about 10 per cent in heat transfer characteristics.…”

“…One of the largest problems facing the brake disc designer in fulfilling these criteria is identifying the balance between a design which provides a sufficiently large wetted area for the energy to be transferred to the cooling airflow and at the same time generates a sufficiently high mass flowrate to give a high heat transfer rate. This paper builds on previous work [6,7] to study the effect of the geometry of the first, second, and third rows of pins within a pin-vented rotor on its aerodynamic and thermal performance as well as to attempt to identify new design parameters defining the rotor geometry as well as its thermal and aerodynamic performance. These in turn can be utilized by the brake disc designers to design the brake rotors for optimal aerothermal performance.…”