Aerodynamic investigations of ventilated brake discs

Abstract The heat dissipation and performance of a ventilated brake disc strongly depends on the aerodynamic characteristics of the flow through the rotor passages. The aim of this investigation was to provide an improved understanding of ventilated brake rotor flow phenomena, with a view to improving heat dissipation, as well as providing a measurement data set for validation of computational fluid dynamics methods. The flow fields at the exit of four different brake rotor geometries, rotated in free air, were measured using a five-hole pressure probe and a hot-wire anemometry system. The principal measurements were taken using two-component hot-wire techniques and were used to determine mean and unsteady flow characteristics at the exit of the brake rotors. Using phase-locked data processing, it was possible to reveal the spatial and temporal flow variation within individual rotor passages. The effects of disc geometry and rotational speed on the mean flow, passage turbulence intensity, and mass flow were determined. The rotor exit jet and wake flow were clearly observed as characterized by the passage geometry as well as definite regions of high and low turbulence. The aerodynamic flow characteristics were found to be reasonably independent of rotational speed but highly dependent upon rotor geometry.

[1]  Fred Z. Shen,et al.  Computational Flow Analysis of Brake Cooling , 1997 .

[2]  F. E. Jørgensen,et al.  How to measure turbulence with hot-wire anemometers - a practical guide , 2002 .

[3]  H. Krain Swirling Impeller Flow , 1988 .

[4]  Bruno Eck Fans; design and operation of centrifugal, axial-flow, and cross-flow fans , 1973 .

[5]  Ross Gilbert,et al.  Analysis of the Flow Through a Vented Automotive Brake Rotor , 2003 .

[7]  R. J. Goldstein,et al.  Fluid Mechanics Measurements , 1983 .

[8]  A. E. Sisson,et al.  Thermal Analysis of Vented Brake Rotors , 1978 .

[9]  Todd Garrett Wetzel,et al.  Heat Transfer in a Complex Trailing Edge Passage for a High Pressure Turbine Blade - Part 1: Experimental Measurements. Part 1; Experimental Measurements , 2000 .

[10]  Rudolf Limpert,et al.  THE THERMAL PERFORMANCE OF AUTOMOTIVE DISC BRAKES , 1975 .

[11]  Frank P. Bleier Fan Handbook: Selection, Application, and Design , 1997 .

[12]  Giovanna Barigozzi,et al.  Experimental Investigation of the Mean and Turbulent Flow Characteristics at the Exit of Automotive Vented Brake Discs , 2002 .

[13]  G. P. Voller,et al.  Analysis of automotive disc brake cooling characteristics , 2003 .

[14]  Marina Ubaldi,et al.  Detailed flow measurements within the impeller and the vaneless diffuser of a centrifugal turbomachine , 1998 .

[15]  David Japikse,et al.  Introduction to Turbomachinery , 1994 .

[16]  Rudolf Limpert Cooling Analysis of Disc Brake Rotors , 1975 .

[17]  Roland L. Ruhl,et al.  Ventilated Brake Rotor Air Flow Investigation , 1997 .

[18]  Anwar R. Daudi 72 Curved Fins and Air Director Idea Increases Airflow through Brake Rotors , 1999 .

[19]  A. Whitfield,et al.  Design of radial turbomachines , 1990 .

[20]  B. Lakshminarayana Fluid dynamics and heat transfer of turbomachinery , 1995 .

[21]  J. R. Wood,et al.  Experimental and Computational Investigation of the NASA Low-Speed Centrifugal Compressor Flow Field , 1992 .