This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Compressible Brake Fluid Turbulent Flow Simulation and Experimental Verification on Brake Bleeding Performance Improvements of an EPB Caliper
Technical Paper
2018-01-1876
ISSN: 0148-7191, e-ISSN: 2688-3627
This content contains downloadable datasets
Annotation ability available
Sector:
Language:
English
Abstract
Brake bleeding is the process of removing air bubbles present on hydraulic brake systems from the master cylinder to the calipers of a vehicle, including the brake pipes and hoses. This is very important procedure affecting on brake performance, but still has been a key issue in automobile industry for last decades because reaching best bleeding performance has a limit that there is always remaining air in brake system. In this paper, it is reported on numerical and experimental investigations into the topic of bleeding performance improvements. Compressible brake fluid turbulent flow simulation with two-phase mixture model was performed to investigate the details of the bleeding performance drop during its cycles. The rig test of the hollow cylinder was carried out in order to secure the brake consumption amount curve whose results were used for the criterion of the parametric simulations using Tait equation to estimate the property of the brake fluid with the bulk modulus of 19,535 bar and 0.00016%. It was observed that the experimental curve data from the rig test of the hollow cylinder is divided into two regions with high and low compressibility, and more volume change in the low region below 1 bar is required to gain the same pressure variation due to the compression of the tiny air bubbles. The improved design of the nut-spindle with 6 holes in circumferential direction was drawn for the better removal of the trapped air. The simulation of the improved model showed the manual bleeding performance improvements of 18.9% than the baseline model due to the holes effect on circulation of the trapped air. It was experimentally verified that the air bubbles from their visualization are compressed to form the smaller size bubbles in the process of pressurization and gathered on the topmost side, whereas they are again expanded to form the larger size bubbles in the process of pressure release and spread into the wider space. The bleeding performance for the improved model was also experimentally verified to be effective up to approximately 51% through the caliper performance tester.
Recommended Content
Technical Paper | Transient Response of Turbocharged Diesel Engines |
Technical Paper | An Air Hybrid for High Power Absorption and Discharge |
Technical Paper | Research on Constant Speed Control Strategy of Water Medium Retarders for Heavy-Duty Vehicles |
Authors
Citation
Mo, J., "Compressible Brake Fluid Turbulent Flow Simulation and Experimental Verification on Brake Bleeding Performance Improvements of an EPB Caliper," SAE Technical Paper 2018-01-1876, 2018, https://doi.org/10.4271/2018-01-1876.Data Sets - Support Documents
Title | Description | Download |
---|---|---|
Unnamed Dataset 1 | ||
Unnamed Dataset 2 | ||
Unnamed Dataset 3 | ||
Unnamed Dataset 4 |
Also In
References
- Gholizadeh , H. 2013
- Hayward , H. Research on Lubricants and Hydraulic Fluids at National Engineering Laboratory Scientific Lubrication 15 3 112 124
- Gholizadeh , H. , Burton , R. , and Schoenau , G. Fluid Bulk Modulus: A Literature Survey International Journal of Fluid Power 12 3 5 16
- Kajaste , J. , Kauranne , H. , Ellman , A. , and Pietola , M. Experimental Validation of Different Models for Bulk Modulus of Hydraulic Fluid The Ninth Scandinavian International Conference on Fluid Power SICFP Sweden June 1-3, 2005
- Merritt , H.E. Hydraulic Control Systems New York Wiley 1967
- Wilcox , D.C. Turbulence Modeling for CFD La Canada, CA DCW Industries Inc. 1988
- https://en.wikipedia.org/wiki/Tait_equation