Why Does Smoke Rise? An Exploration of Physics Principles

[jaumzaum]

If we consider that the heating of the products created in the combustion of paper to be an almost adiabatic process (as it's extremely fast), then
$$T^{1.4} P^{-0.4} = const. $$
If we double the temperature, we multiply the pressure by 11.3
The density of an ideal gas is
$$ \rho=PM/RT$$
If we double the temperature, the density would be multiplied by 5.7

So why would the smoke rises if it became more dense?

 

[russ_watters]

If we double the temperature, we multiply the pressure by 11.3

How can that be if the combustion isn't happening in an enclosure?

 

[hutchphd]

Flame is roughly a steady state process taking place at atmospheric pressure. The smoke particles are carried upward in the warm air which rises because is is less dense than cooler room air.

 

[Dale]

we multiply the pressure by 11.3

Not if it is an open flame at atmospheric pressure