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Fluid Mechanics & Thermodynamics 2 > Thermo > Flashcards

Flashcards in Thermo Deck (9)
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1

S.F.E.E.

Q̇-Ẇ = ṁ(Δh + ΔKE + ΔPE)

2

Equation for rate of Heat transfer

Q̇ = ṁCpΔT

3

Efficiency or COP

Desired Energy / Input Energy

η = Wout / Qin
Refrigerator COP = Qc / Win
Heat Pump COP = Qh / Win

4

1st Law

ΔU = ΔQ - ΔW

5

2nd Law

No engine can be built whose interactions are only positive work and heat transfer from a constant temperature body.

No heat engine can be 100% efficient.

6

Reversible heat engine efficiency

ηR = 1 - QL/QH = 1- TL/TH
this also leads to
Q1/T1 = Q2/T2

7

Carnot Cycle

Heat transfers are isothermal and work transfers are isentropic ∴ rectangular on T-S diagram.

8

Reversible process heat transfer

QR = ∫TdS

9

Brayton Cycle and Back Work

S.F.E.E. used to model energy transfers.
Back work = Wcompressor / Wturbine