2nd Year Gas-Power Cyles Flashcards
What do we use to tackles these questions?
The PERFECT GAS LAWS! :)
What is the OTTO cycle?
The ideal cycle used to compare car engine cycles
What are the 4 processes in an OTTO cycle?
1-2 Isentropic compression 2-3 Heat Transfer (constant Volume) 3-4 Isentropic Expansion 4-1 Heat transfer (Constant Volume)
What are useful equations for the isentropic cycles?
Q=0 -W=ΔU w = P2V2-P1V1 / 1-n Work in or out
What are useful equations for the constant volume heat transfer cycles?
W=0 Q=mCvΔT Q in or out
What do the process paths on an OTTO cycle look like?
What is a compression ratio?
Rv = v1/v2 = v4/v3
How can the thermal effiiency by calculated?
efficiency = 1 - 1/Rv^y-1
What is the JOULE / BRAYTON Cycle?
An ieal cycle used to compare turbines and jet engines
What are the proceeses of a BRAYTON / JOULE cycle?
1-2 Isentropic Compression
2-3 Heat transfer (Const Pressure)
3-4 Isentropic Expansion
4-1 Heat transfer (constant Pressure)
What are usefull equations for the constant pressure processes?
Q=mCpΔT
w = -ʃV dP
What are the specifics of an Industral JOULE process?
Wnet = Wout + Win
(Win = -ve)
Wnet = Wturb - Wcomp
What are the specifics of an Aerospace JOULE process?
Wturb = Wcomp
Wnet = 0
Turbine: ΔH = ΔKE = 0
Efficiency = ΔKE/Qin
Thrust = mVel(out) - mVel(in)
What do the process paths of a JOULE cyle look like?
