The coast-down method is the way to determine the vehicle drag value and its relationship to the aerodynamic configuration and tyre parameters under conditions of real atmospheric turbulence and road covering. Since all coast-down techniques available are based on the measurements of the test object speed or its deceleration which are the main source of experimental data errors, it is of great importance to phase these variables out of use. This paper describes the method based on the time—distance function to be derived by a new solution of the coast-down equation that is free from speed and deceleration. This enables a considerable group of measurement error sources to be eliminated and the coast-down technique sensitivity to be increased; so the small drag alterations due to the changes in vehicle aerodynamic configuration or tyre parameters, such as load, inflation pressure and temperature, can be detected. Road—tunnel and road—bench correlation fields are essentially enriched for the vehicle design purposes.
Improvement in vehicle aerodynamic drag and rolling resistance determination from coast-down tests
1998-05-01
12 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Improvement in vehicle aerodynamic drag and rolling resistance determination from coast-down tests
Online Contents | 1998
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