Temperature Dependency of Pass-By Tire Road Noise

Coast-by tire road noise is much effected by temperature. As temperature goes up, coast-by tire road noise level becomes lower in the case of passenger car tire. Temperature gradient of coast-by tire road noise is around -0.07 dB(A)/°C using air temperature. On the other hand, the tire is under torque during a pass-by test and some amount of extra noise is radiated from the tire pavement interface. Generally speaking, the level of tire road noise during pass-by mode becomes higher than coast-by mode. How much tire road noise is increased due to the applied torque and how its extra noise is effected by air temperature are reported here.

Pass-by tire road noise consists of two components. The first component is the coast-by noise and the second component is the extra noise by the torque that is obtained by the noise level calculation of pass-by minus coast-by. The second component of the extra noise comes from the slip vibration of tire tread and its noise level becomes higher as temperature goes up. As the first component and the second component have the opposite tendency with the temperature and the two components tend to cancel each other, the total temperature dependency of the pass-by tire road noise is small.