Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: jack_ on 19/03/2019 10:59:41

Title: Why is it hard to breathe in a fast-moving car with the window open?
Post by: jack_ on 19/03/2019 10:59:41

Katlego has been in touch to ask:

Why do we struggle with breathing when we are in a fast moving car while the window is open?

What do you think?

Title: Re: Why is it hard to breathe in a fast-moving car with the window open?
Post by: RD on 19/03/2019 12:31:28

Turbulence ...  https://en.wikipedia.org/wiki/Airway_resistance#Laminar_flow_versus_turbulent_flow

Title: Re: Why is it hard to breathe in a fast-moving car with the window open?
Post by: mrsmith2211 on 21/03/2019 04:34:39

It sounds like a personal problem, I have never experienced it even at 80mph.

Title: Re: Why is it hard to breathe in a fast-moving car with the window open?
Post by: alancalverd on 21/03/2019 08:06:53

Depends on the shape of the car and which window is open, but it's all due to Bernouilli.  In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid produces a decrease in pressure or a decrease in the fluid's potential energy. In other words, the static pressure outside the car is lower than inside, so the passing wind tends to suck the air out of your lungs. It's the same phenomenon that creates lift over the curved surface of a wing or a windmill blade.

This may explain the exhilaration of an opentopped car. Nothing to do with the wind in your hair (I don't have any) but the euphoria of partial hypoxia.

Title: Re: Why is it hard to breathe in a fast-moving car with the window open?
Post by: Petrochemicals on 22/03/2019 23:19:43

I do not know the answer but you would think its the same as a gust of wind taking your breath away.