MECH 213 - 9.24.07

# MECH 213 - 9.24.07 - MECH 213 QUIZ TOMORROW up through this...

This preview shows pages 1–2. Sign up to view the full content.

MECH 213 – September 24, 2007 QUIZ TOMORROW!!! – up through this material m in – m out = Δm sys -(m out – m in ) = Δm sys Rate: o -(m out dot – m in dot) = Δm sys /Δt o ∫∫ cs ρ(V•n)dA d/dt(∫∫∫ cv ρdV) Steady flow – nothing changes over time (d/dt = 0) o Σm in dot = Σm out dot o Single inlet/outlet m in dot = m out dot = ρ 1 A 1 V 1 = ρ 2 A 2 V 2 First Law o Q net.in – W net.out + Σm in (p/ρ + u + ke + pe) in – Σm out (p/ρ + u + ke + pe) out = ΔE = m sys (u + ke + pe) sys o Q net.in dot – W net.out dot + Σm in dot(p/ρ + u + ke + pe) in – Σm out dot(p/ρ + u + ke + pe) out = ΔE/Δt = [m sys dot(u + ke + pe) sys ]/Δt In a steady state the right side disappears o Energy of a flowing fluid = θ ≡ h + ke + pe Steady State o ΔE/Δt 0 o Q net.in dot – W net.out dot = –Σm in dot(p/ρ + u + ke + pe) in + Σm out dot(p/ρ + u + ke + pe) out o Q net.in dot – W net.out dot = –Σm in dot(θ) in + Σm out dot(θ) out o Single inlet/outlet m in dot = m out dot = mdot Q net.in dot – W net.out dot = mdot(θ out – θ in ) Divide both sides by mdot q net.in

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 2

MECH 213 - 9.24.07 - MECH 213 QUIZ TOMORROW up through this...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online