This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Determination of the amplitude of the friction forces variation inherent to a coastdown test (typical noise amplitude), comparing it with the aerodynamic drag force and raise the sensitive of the coastdown test to the variation of the vehicle coefficient of drag (Cd)
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 03, 2018 by SAE International in United States
Annotation ability available
This paper has the objective to present the study of typical friction forces variation (noise) on a vehicle coastdown test @ 110 km/h, correlate with the drag force raised in wind tunnel and finally compared them to determine the sensitivity of Cd variation which can be detected on an “A to B” coastdown test procedure. As “A to B”, comparison test means testing the vehicle with a known aero Cd compare to another one, creating real technical parameters. For this study, we used real data from certification coastdowns tests for a same vehicle configuration in the most controlled possible conditions (all tests performed in CAPG track facilities) and real vehicle aerodynamic data raised from the wind tunnel.
CitationHoll, A. and Santos, A., "Determination of the amplitude of the friction forces variation inherent to a coastdown test (typical noise amplitude), comparing it with the aerodynamic drag force and raise the sensitive of the coastdown test to the variation of the vehicle coefficient of drag (Cd)," SAE Technical Paper 2018-36-0187, 2018, https://doi.org/10.4271/2018-36-0187.
- Passmore M. A. and Le Good G. M. R. “A Detailed Drag Study Using the Coastdown Method”. SAE Paper n. 940420, 1994.
- Walter J. A, Pruess D. J., Romberg G. F. “Coastdown / wind tunnel drag correlation and uncertainty analysis”. SAE Paper n. 2001-01-0630, 2001.
- Zolet T., Rosa S. C., Bicalho S. “Correlation between Aerodynamic drag found on CFD simulations, Wind tunnel testing and coastdown testing”. SAE Paper n. 2015-36-0345, 2015.
- Brazilian Standard. “Light duty road vehicles – Road load Measurement and dynamometer simulation using coastdown Techniques” ABNT-NBR10312 Standard, Rev. September 2014.
- White, R. A., Korst. “The determination of vehicle drag contributions from coast-down tests”. SAE paper No. 720099, 1972.
- Lopes R., Carbonara A. “A brief discussion on vehicle coast down comparative analysis”. SAE Paper n. 2017-36-0199, 2017.