indice - Parcol

Flow Regime condition sub-critico Subsonic Critical critico Hypercritical
ipercritico
causa del
cause of aerodynamic
turbolence turbolenza + supersonic onde d'urto
rumore
turbolenza a valle della
turbolence downstream of v.c.
supersonic onde d'urto impact supersoniche
waves
noise
v.c.
impact supersoniche waves
aerodinamico
p c
pvcc
1 2
p
< ⋅
22
p
⋅ c
pvcc
≤ p2 < pvcc p
1 2
2
p
22
p2 p2 ≥ p2c pvcc ≤ p2 < p2c 1- 2
/ / /
p p
FL
2
-
1
p
pvc
1
γ
γ −
⎞
⎠ ⎟
p 2
1 γ + 1
⎛
⎝ ⎜
/
pvcc
2 p1−F 2
L ⋅( p1−pvcc )
p c
/ / /
2p ⋅ M p
1⋅
⎛ 1
( −1) ⋅ 1⋅R⋅T p
1 ⎝ vc
⎜
⎞
⎠ ⎟
⎡ γ −1
⎤
⎢ γ ⎥
γ ρ
⎢
−1⎥
⎢
⎥
⎣⎢
⎦⎥
Mvc
/
γ 1
M j / 2 ⎛ p1⋅p2c γ
1
γ −1⎝p2
⋅pvcc
⎜
⎞
⎠ ⎟
⎡
− ⎤
⎢
⎥
⎢
− ⎥
⎢
⎥
⎣⎢
⎦⎥
4 L 2
6,6 F
− 3,4⋅10 ⋅1,4
L 2
6,6 F
1,4
10−4 ⋅ Mvc
3,6
4
10 Mj L 2
− 6,6 F ⋅ 10 Mj2
−4 ⋅ ⋅
2
acoustic efficienza efficiency acustica
η
η⋅Wm
p1−p2 p1−pvcc Wm
η⋅FL ⋅Wm
2 η⋅
Wa
7
Fig. 3 Rendimento e potenza acustica per i differenti regimi.