Method for determining the aerodynamic moment of resistance of a wheel
AssigneesCompagnie Generale Des Etablissements Michelin, Michelin Recherche et Technique S.A.
InventorBenoit Gardarin, Jr.
Life of this patent
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Abstract
A method for determining the aerodynamic moment of resistance Maero-EM of a wheel by calculating the variation with respect to time, of the product of the rotational speed of at least one wheel set in rotation about an axis and of the inertia of the said wheel about the said axis, the wheel being equipped with a device for picking off and recording the numerical values of its rotational speed. The wheel is protected by a removable cap and in is subjected to a flow of air.
Claims7
A method for determining the aerodynamic moment of resistance, Maero-EM of a wheel that is equipped with a device for picking off and recording the numerical values of its rotational speed and that is protected by a removable cap, comprising:
- setting the wheel in contact with a rolling road initially at a time t0;
- taking the wheel out of contact with the road at a time t1 subsequent to t0, while at the same time continuing to subject the wheel to a flow of air
- recording numerical values of the rotational speed of the wheel set in rotation about an axis;
- calculating the variation, with respect to time, of the product of the rotational speed of the wheel set in rotation about an axis, and of the inertia of the wheel about the axis,
- inputting the measurements of the rotational speed ω(t) of the wheel, picked up as a function of time, into the following mathematical formula:
- IEM(dω(t)/dt)=Maero-EM(t)+Mf(t) (I)
- where
- IEM represents the value of the moment of inertia of the wheel about the axis of rotation,
- ω(t) represents the instantaneous rotational speed of the wheel,
- Mf(t) represents the value of the moment of friction of the hub of the wheel, and
- Maero-EM(t) represents the instantaneous aerodynamic moment of the wheel.
Dependencies are inferred from the claim text.