High winds and speed

[roachcoach]

One for the physicists I think .

Driving to work this morning in the winds I was wondering, are you more, less or equally likely to be affected by sideways gusts of wind as your overall speed increases?

I have no idea, but I was curious as I watched a little pug in the inside lane of a DC going quote slowly get blown all over the place and other equally small cars in the other lane going quicker seemingly less affected.

[StottyZr]

I was wondering exactly this last night!

Then I thought about it and, wouldn't the sideways forces be exactly the same so you would experiance the same shove.

[roachcoach]

No idea, I wondered if since your kinetic energy increases with speed you're carrying more going faster therefore it may take more 'force' to disrupt you.

I have no idea though, which is why I asked.

[joe58]

I also wonder if your going quicker would your grip on the road not increase as well? But then would that have a difference o pushing you everywhere.

Have you considered that the people on the inside lane going slower as they are poorer drivers and therefore couldn't control the car as well. Compared to say the better drivers going quicker and therefore could control the car?

[LawrenceOfArabia]

Probably depends on the aerodynamics of the car? i.e. a heavy car that has lots of downforce will be more planted to the ground at high speed compared to a light car with very little downforce.

Just a stab in the dark...

[mgmrw]

from experience, depends on the car.

MG ZR on coilovers, weighed not a lot. And at 55 in high winds, was kicked around like a golf ball. If you pushed it up to the limit (give or take 10%) it felt like it cut through the wind easier and held on to the road better.

Focus estate, not so much...... SAAB 9-3: that big and heavy, it notices nothing barring an earthquake nudging the top end of the richter scale.

[cptsideways]

Apparent lateral wind speeds reduce with speed, so yes the faster you go the less the sidewinds whould effect you. However as most road cars have negative downforce at speed (they effectively get lighter) the effects of sidewinds will become more noticeable, so probably cancel each other out. There is also the kinetic energy factor which would add to the equation.

[AJI]

Its more to do with the fact that a side wind can momentarily force the vehicle 'off-course', if you're travelling faster your reaction time will allow the deflection to be greater. If you're travelling slower then it will be less due to your reaction time and subsequent correction on the steering.


edit to add : its not the constant higher speed wind that is the issue....when warnings of high wind speeds are 'advertised' it is more to do with the gusts, or the rapid change from one lateral wind speed to another. This is what causes the change in direction you see from the HGVs, creating a safety issue with lane wandering and/or veering off the road or into other traffic.

Edited by AJI on Tuesday 13th September 12:05

[ChiChoAndy]

Surely this is the same as the falling bullet scenario. It matter not what speed the bullet is going the effect of gravity is not changed. Why would that change if the force is gravity, or a crosswind?

[BarnatosGhost]

a faster car is putting more treadblocks onto the ground per second, which each offer a tiny amount of deflection. I'd think a faster (and lighter due to lift) car would be deflected more.

After all, if you test a principle by testing the extremes, a stationary car isn't deflected at all, whilst a speed-record car at 700mph is deflected by a huge amount.

It is only once a car starts moving that the tyre-flex allows any deflection at all, so I think it stands to reason that more speed allows more deflection. I'd be delighted to be proved wrong though.

Edited by BarnatosGhost on Tuesday 13th September 11:46