Physique des écoulements turbulents - Centre Acoustique du LMFA ...
Physique des écoulements turbulents - Centre Acoustique du LMFA ...
Physique des écoulements turbulents - Centre Acoustique du LMFA ...
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15<br />
A short intro<strong>du</strong>ction to turbulent flows <br />
Relation between the skin-friction coefficient Cf and the friction coefficient ψ<br />
(coefficient de frottement local et coefficient de perte de charges)<br />
p1<br />
τw = µ dU<br />
dr<br />
✻<br />
❄<br />
D<br />
<br />
<br />
<br />
<br />
r=R<br />
∆p ≡ p1 − p2 = 4cf<br />
p2<br />
Cf ≡ τw<br />
1<br />
2 ρU2 d<br />
<br />
Σ<br />
∆p ≡ ψ L<br />
D<br />
<br />
ρu·(u · n) dΣ = −<br />
0 = (−p1 + p2) πD2<br />
4<br />
L 1<br />
D 2 ρU2 d = ψ L 1<br />
D 2 ρU2 d<br />
<strong>Physique</strong> <strong>des</strong> <strong>écoulements</strong> <strong>turbulents</strong> @ Christophe Bailly – ECL’12<br />
Σ<br />
1<br />
2 ρU2 d<br />
<br />
pndΣ+ τ(n)dΣ<br />
Σ<br />
+ πDL µdU<br />
dr<br />
ψ ≡ 4cf<br />
<br />
<br />
<br />
<br />
r=R
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