Ever stick your head out of the window of a speeding car? So much air in your face. You inhale but there is still a weird sensation like being out of breath.
Yet I don’t experience this at all when cruising down the highway on my motorcycle.
What’s going on?
I suspect that the air around the car is more turbulent. We get a sense of obstructed breathing if we try to breathe turbulent air.
Could it be the Bernoulli effect? The speed of the air flowing over your face could lower the air pressure enough to make it hard to inhale.
I’ve had the same feeling when I’ve been up a mountain in a very strong gale. It’s almost like the air is being sucked out of you. I assume it’s some kind of low pressure area being created by the turbulent flow.
I could easily believe the Bernoulli effect is responsible for it if the air is passing across the opening of your mouth. That would absolutely suck the air right out of your lungs. If the air is blowing directly down your throat though, you’d have the opposite problem, wouldn’t you? It might be hard to breathe out (though I doubt you could get such pressure that your diaphragm couldn’t overcome it).
But why is the same effect not experienced on a motorcycle? I can scoot down the highway @ 80 and not feel this sensation at all. And I don’t have a windshield on one of my bikes.
Sticking your head out of a car window means that your head is right in the middle of the laminar flow created by the body of the car. The car is moving a huge amount of air out of its way so the effect is quite pronounced. On a bike, it’s just your little (compared to a car body) head sticking up above your bike. Your head doesn’t displace much air so the Bernoulli effect is not nearly as strong.
Is this dangerous? Does one really not get enough air when breathing while sticking their head out the car window. or is it just an illusion?
I can’t envision how it could possibly be dangerous. Your breathing is less efficient with all the turbulent airflow, but you’re not being asphyxiated.