TurboClub

the flutter that occurs in your turbo car occurs because air comes back from your closed throttle plate and hits the compressed air coming from your turbo, inducing something called Compressor Surge.

a typical surge event consists of high pressure spike followed by a sharp drop in pressure and then a slow recovery back to the stable operating point pressure.

a significant low momentum fluid blockage develops in the diffuser at a stable operating point just above the stalling mass flow. With a further constriction of the mass flow, the blockage in the diffuser cause the large pressure spike observed at the start of the surge cycle (the begining of flutter). Furthermore, during the high pressure spike (closing your throttle plate), the flow in the diffuser completely reverses and flows up into the vaneless space (the snail shape of your compressor cover).

At the point of minimum pressure in the diffuser, forward flow in the turbo is reestablished (this is because your turbo is still spinning and trying to compress air, but the high pressure shock in the outlet hasn't let it until this point) in the form of a supersonic shock front that propagates back down through the outlet.

The supersonic shock front forces the remnants of the reversing flow out of the diffuser, producing a Low pressure zone in the compressor outlet.

As the pressure slowly recovers in the compressor outlet, the high speed flow subsides and the flow field approaches the stable operating point conditions of high speed flow entering the compressor and low speed flow within/exiting the compressor outlet (the air coming out of your compressor is still traveling fast, but compared to the atmospheric pressured air entering, it is considered low velocity relative to the intake).

the reverse flow occurring during compressor surge is influenced by the pressure waves emanating from the passing compressor blades. it has been shown that pressure fluctuations in the compressor housing/outlet are caused by pressure waves emanating from the impeller blades.

wa666ou kirjutas:äkki sa mõtled seda "ba-ba-ba-ba-ba-baa" (kui gaasi kõrge rõhu pealt lahti laseb). Ingl.k nimetatakse seda compressor surge (fluttering sound) ehk siis kui bov laseb buusti välja, läheb ometigi osa õhku tagasi turbo poole ja labadele see mitte ei meeldi (hakkavad tagurpidi käima).

mõni spets võiks paremini selgitada.

Veel üks video: http://videos.streetfire.net/search/tur ... 7fbe6c.htm

miil kirjutas:

Veel üks video: http://videos.streetfire.net/search/tur ... 7fbe6c.htm

Mina blow-offi kinnises ja lahtises olekus throttle response'i vahest aru ei saanud (kutt ise ütleb: "notice how the engine reacts so much faster"). Võibolla tuleb see minu eelarvamusest, sest ma ei saa aru mis takistust põhjustab turbo sisselaskele (võibolla mõne komakohataguse protsendi), eriti veel tühikäigupööretel kus õhuvool 10x väiksem maksimaalsest õhuvoolust . Äkki keegi seletab.

Siin on veel üks video, kus võrreldakse teist tüüpi BOViga. Sealt näha, et klapp ise reageerib küll kiiresti.