Red_Bean_Bun
Well-Known Member
And so I was doing some research in road noise in relation to the car - came across this research by a Belgium based institution ....
https://lirias.kuleuven.be/bitstream/123456789/184517/1/08PP024.pdf
Quite interesting - To summarize .... Here's what they are saying -
- lower profile tires are noisier (Payne effect and cleat height).
- ride height has an influence. The lower the ride, the noisier it gets
(noise radiation about 100mm peaks at 80hz).
- the higher the rolling resistance the higher the road noise implying
rolling speed has an influence (stating the obvious but it's there)
- air pressure has an influence on the tone of the road noise. Low
pressure would be lower pitch while higher pressure would have a
higher pitch. This is because air pressure affects the tire sidewall
stiffness. But it takes sometime to heat up the air in the tires as rubber
is a good insulator.
- the temperature of the tires (not a it in the tires) affects noise level.
Higher temperatures changes the rubber characteristics which affects
the stiffness (makes it softer) and in return the contact patch force. The
smaller the contact force (implying a larger contact patch size), the less
the noise.
- since noise and vibration travels up through the suspension into the
chassis, the firmness of the suspension affects the amount of road
noise into the car (vertical spindle forces and preload). Too soft a
setting would create a slapping noise over road imperfections though
- noise generation are created by 3 areas
- whole tire vibrations (road roughness) < 1000hz
- tread block vibrations (tangential vibrations) > 1000hz
- aerodynamic related (tread pattern) > 1000hz
- the part of the tire that causes the most noise is the outer part
(shoulder block). So implies tires with a stiffer sidewall are noisier. But
IMHO - this could be offset by a more negative camber.
Just my 2 cents of thoughts about noise ....
https://lirias.kuleuven.be/bitstream/123456789/184517/1/08PP024.pdf
Quite interesting - To summarize .... Here's what they are saying -
- lower profile tires are noisier (Payne effect and cleat height).
- ride height has an influence. The lower the ride, the noisier it gets
(noise radiation about 100mm peaks at 80hz).
- the higher the rolling resistance the higher the road noise implying
rolling speed has an influence (stating the obvious but it's there)
- air pressure has an influence on the tone of the road noise. Low
pressure would be lower pitch while higher pressure would have a
higher pitch. This is because air pressure affects the tire sidewall
stiffness. But it takes sometime to heat up the air in the tires as rubber
is a good insulator.
- the temperature of the tires (not a it in the tires) affects noise level.
Higher temperatures changes the rubber characteristics which affects
the stiffness (makes it softer) and in return the contact patch force. The
smaller the contact force (implying a larger contact patch size), the less
the noise.
- since noise and vibration travels up through the suspension into the
chassis, the firmness of the suspension affects the amount of road
noise into the car (vertical spindle forces and preload). Too soft a
setting would create a slapping noise over road imperfections though
- noise generation are created by 3 areas
- whole tire vibrations (road roughness) < 1000hz
- tread block vibrations (tangential vibrations) > 1000hz
- aerodynamic related (tread pattern) > 1000hz
- the part of the tire that causes the most noise is the outer part
(shoulder block). So implies tires with a stiffer sidewall are noisier. But
IMHO - this could be offset by a more negative camber.
Just my 2 cents of thoughts about noise ....
