Olivier22 wrote:I never thought I would ever have to argue against such an absurd statement ... but ok:nikolaj wrote:Olivier22 wrote:An air filter is rigid anyway, this argument does not stand up
Hello, the carcass of the air filter is often metallic, its perimeter is a perforated plate, or a stainless steel grid, but its internal honeycomb structure is in various fibers assembled, like cardboard weaves, but breathable, otherwise the air would never pass ... but it moves much more than you say ... every time the engine runs and sucks +/- air (hence the comparison with the lungs, or an accordion) ...
1- An accordion structure can be deformed, its surface does not change.
2- In 90% of the cases, the air passes through the filter from the outside to the inside, so according to your reasoning it would tend to compress, not to inflate.
3- As you say, flexible filters (foam or cotton) are armed, and they are bilaterally. They are therefore held rigidly in the 2 sense. As for the paper filters, they are rigid by nature (on them the armature serves mainly to prevent them from crashing because of the support of the air box on the joints).
If that's not enough, I should be able to make a video this weekend ...
Hello to you, most air filters draw air on their periphery, then through the formed cells, the incoming air exerts a pressure on all surfaces +/- permeable to the air (tight weaves or + / - loose), and often have an internal metal grid which stops any excessive undesirable deformation, then the admitted air circulates in the connecting tubes towards the turbo and the admission chambers, which seems little or not perceptible to the At first glance, inevitably happens, as in the sails of the boat or the curtains of our houses .... which filters the air + / -... but ok if you make a video, pass also so in slow motion to compare...
"fluid mechanics" ...