bill nye scienceguy!
Jan2-08, 03:32 PM
ice as in internal combustion engine, sorry for confusion
1. The problem statement, all variables and given/known data
I'm given an engine operating on the dual cycle and asked to find the thermal efficiency and the mean effective pressure. the compression ratio is 18:1, the temperature at the start of the compression 300K and the pressure is 100kN/m^2. the pressure ratio for the constant volume part of the heating process is 1.5:1 and the volume ratio for the constant pressure part is 1.2:1. im taking gamma to be 1.4.
2. Relevant equations
compression ratio = rv
pressure ratio = a
volume ratio = rc
gamma = y
eff. = 1 - (1/rv^(y-1))[((a.rc^y)-1/((a-1) + ya(rc-1))]
3. The attempt at a solution
I found the efficiency to be 67.9% but now i need to find the mean effective pressure and im stuck. obviously i know its work output over swept volume but im at a loss to find either for the dual cycle.
help please.
1. The problem statement, all variables and given/known data
I'm given an engine operating on the dual cycle and asked to find the thermal efficiency and the mean effective pressure. the compression ratio is 18:1, the temperature at the start of the compression 300K and the pressure is 100kN/m^2. the pressure ratio for the constant volume part of the heating process is 1.5:1 and the volume ratio for the constant pressure part is 1.2:1. im taking gamma to be 1.4.
2. Relevant equations
compression ratio = rv
pressure ratio = a
volume ratio = rc
gamma = y
eff. = 1 - (1/rv^(y-1))[((a.rc^y)-1/((a-1) + ya(rc-1))]
3. The attempt at a solution
I found the efficiency to be 67.9% but now i need to find the mean effective pressure and im stuck. obviously i know its work output over swept volume but im at a loss to find either for the dual cycle.
help please.