Problem #5 (pg.57)
m=29
1000°C
m=103
20°C
3 5.4 MPa
20MPa
0.101MPa
Is this possible? Find Pmax at 3
Mass- = 22 looking at a
at Energy -- Speap (n+2+ge) in do =Pis+
-m, h, m₂h₂ + mg h₃ = 0 =>m, Ti-m₂ T₂ + m3 13-0 T3= m, T,+ m² 12
2nd Law- Sps (in) do 20
-m,5,-m₂S₂ + m3 53 20 Extreme value is when = 0
→52-5,=Cpin()-Rin()
→53-5,=CpIn()-Rin()
T -ms-mz (s,+Cpin-Rin11) +ms (S,+Cpn-Rin)
= 1+2
-Xin [()]+(1+2)[]20 In
Two Options: Find P3 or plug in the Inventor's PO to check
Inventor is wrong
CH.3: Compressible Flows and Shock Waves in Steady Flows
Mass Conservation (3.1.1)
ne
p+df v+dv
0+do
→x
p+dp
T+ dT
PV,O,P2 V202
Kdy
(2)
pvo = const
How to Solve a Problem
d(pro)=0 pvdo +ρσαν + νσαρ = 0
do+ dv+ σ
= 0
George Polya
Other Way
-pvo + (p+dp) (v+dv)(o+do) = 0
-ρνο + (pv+pdv +vdp) (o+do) = 0
{ Ignoring higher order terms
-pyo+pro+pvασ + ρσαν + νσαρ=0
do+ y + f = 0 P=0
REVIEW SESSION
no cheat sheet
• no engines
• momentum forces (pressure, viscous, gravitational)
Find force on the nozzle
""= - ((A-pande+(P2-Pa)ñ+ SA(p-pa) do Onozzle
Spando-o Spido = Frozzle
Pa+AP
F = Sopñdo
•Know laws, corollaries, perpetual motion
• Ideal gas is generally a reasonable assumption for this class