from observation it evens out the air flow, if you run with it removed you will find when you change your filter there is a distinctive area that is dirtier than the rest. With the baffle in the filter is a uniform pattern of dirt across it. Mine has been back in for three years no and I have no intention of removing it again.
If that observation is accurate it sounds like it is evenly distributing dirt, not necessarily the air.
The dirt is airborne dust... The pattern of dirt in a filter is a damn good analogue for airflow.
The dirt is airborne dust... The pattern of dirt in a filter is a damn good analogue for airflow.
The dirt being suspended in the air is unlikely to have a consistent mass. Heavier, probably larger, particles would need a higher air velocity to move them. Higher air velocity is more likely toward the center area of the filter. A larger particle will be more visible and be trapped more easily in the outer layer of the filter material.
The grate creates turbulence that mixes the air and more evenly distributes dirt particles across the filter.
The dirt being suspended in the air is unlikely to have a consistent mass. Heavier, probably larger, particles would need a higher air velocity to move them. Higher air velocity is more likely toward the center area of the filter. A larger particle will be more visible and be trapped more easily in the outer layer of the filter material.
The grate creates turbulence that mixes the air and more evenly distributes dirt particles across the filter.
This is a good statement to (for some reason) get people on your bad side, ask me how I know ?(Fwiw I'm an engineer who's designed a few gas/air filtration systems)
This is a good statement to (for some reason) get people on your bad side, ask me how I know ?
It's even more than that - light, small particles will be fairly evenly distributed in the airflow, but ALL particles will be sorted somewhat not by velocity but by airflow path. Heavier particles have more momentum and therefore tend to travel further than light particles when flow bends, depositing them towards the outside of a curving flow. Dense particles will tend to drop out of the airstream faster. Large, light particles will tend to float more and travel further along before dropping out. Basically, you'll need to do some pretty hefty CFD to get a 100% accurate model.
All that said... First order, the distribution of dirt on the filter is going to closely map to airflow.
(Fwiw I'm an engineer who's designed a few gas/air filtration systems)
Please try searching. There are multiple threads on the subject.
It's exactly what VW says it is and it isn't installed in cars sold in hot climates.