Download - air standard, fuel air and actual cycles
Internal Combustion
Fundamentals
Prof. (Dr.) M P Poonia Director
NITTTR, Chandigarh
AIR STANDARD CYCLE
EFFECT OF SPECIFIC HEAT
1-2-3-4 Constant Specific Heat
1-2”-3”-4” Variable Specific Heat
P
V
EFFECT OF DISSOCIATION
P
V
Tmax
POOR UTILISATION OF HEAT
Flame front Fuel spray flame
Premixed charge (gasoline)
Non-premixed charge (Diesel)
Spark plug Fuel injector
Fuel + air mixture Air only
PREMIXED vs. NON-PREMIXED CHARGE
ENGINES
IDEAL HEAT ADDITION
THE IDEAL AİR STANDARD OTTO
CYCLE
ACTUAL HEAT ADDITION
LOSSES IN ACTUAL CYCLES
TIME LOSS
HEAT LOSS
HEAT LOSS
BLOW DOWN LOSS
BLOW DOWN LOSS
BLOW BYE LOSSES
RUBBING FRICTION LOSS
PUMPING LOSS
Blow Down Loss
Heat Transfer Loss
Combustion Loss
Pumping LossV
P
LOSSES DURING CYCLE
MAGNITUDE OF LOSSES
MAGNITUDE OF LOSSES
The actual efficiency of a good engine is about ……… of the estimated air fuel cycle efficiency.a) 100%b) 85%c) 50%d) 25
FAQ
Fuel air efficiency is less than air standard efficiency by an amount equal toa) pumping lossb) friction lossc) loss due to specific heat and chemical equilibriumd) exhaust blow down loss
FAQ
Fuel air ratio affects maximum power output of the engine due toa) higher specific heatsb) chemical equilibrium lossesc) all of the mentionedd) none of the mentioned
FAQ
As compared to air cycle, in actual working, the effect of variation in specific heats is toa) increase maximum pressure and maximum temperatureb) reduce maximum pressure and maximum temperaturec) increase maximum pressure and decrease maximum temperatured) none of the mentioned
FAQ
As compared to air cycle, in actual working, the effect of variation in specific heats is toa) increase maximum pressure and maximum temperatureb) reduce maximum pressure and maximum temperaturec) increase maximum pressure and decrease maximum temperatured) none of the mentioned
FAQ
Thanks