Mechanical Engineering - IC Engines and Nuclear Power Plants - Discussion

Statement is: In a four stroke cycle, the minimum temperature INSIDE THE ENGINE CYLINDER.

Answer: At the end of exhaust the temperature of the cylinder is high. In the beginning of suction stroke the fresh air enters the cylinder (low temperature) and by the end of the suction stroke, the intake fresh air becomes hot (high temperature) why? Because it comes in contact with cylinder wall and gets warm and warm until the suction ends. Also by T-S diagram, it is clearly shown that minimum temperature is at the beginning of the suction stroke. So, the answer is option A.

At the end of the exhaust, the temperature of the cylinder is high. At the beginning of suction stroke the fresh air enters the cylinder (low temperature) and by the end of the suction stroke, the intake fresh air becomes hot (high temperature) why? Because it comes in contact with cylinder wall and gets warm and warm until the suction ends. Also by T-S diagram, it is clearly shown that minimum temperature is at the beginning of the suction stroke.

So, the answer is option A.

We'll the correct answer may seem B, but a closer look gives A.

This is because due to Ram Effect the end of suction stroke is at higher than atmospheric pressure, while beginning of suction stroke is at atmospheric pressure (Pressure drops with further movement of piston). Further volume at end of suction stroke is higher, so a simple application of PV=nRT can reveal the answer.

The question is slightly tricky if you call it that.

It is mentioned 'inside the cylinder' which implies that they are asking about the temperature of the working fluid present inside the cylinder, which is obviously at the lowest temperature at the beginning of suction stoke. Where as if we talk about the cylinder temperature then B is correct after reasonable assumptions.

All those who are giving the reason PV=nRT are only taking into consideration P, V and T parameters, also look at n, at the beginning of stroke n is very less and after the completion of suction stroke n will be higher, and since temp is inversely proportional to n we can also say temperature will be higher at beginning and lesser at end of suction stroke.

At the Beginning of the suction stroke, everything is hot, the air fuel mix comes in but has a lot of work to do cooling everything down. By the time it has sucked in a whole cylinder of air, the chamber cylinder temperature will be at its lowest point at the bottom of the cycle.

I think Option B is correct because at the beginning of the suction stroke high-temperature exhaust gas had just omitted.

Hence, the chamber will be still hot. By the end of the suction, stroke chamber is filled with fresh air which is at minimum temperature.

I think the answer [B] is right. Because at beginning of suction stroke exhaust gases are just delivered and hence temperature must be high and as suction happens atmospheric air comes in contact with engine cylinder and temperature reach it lowest value.

I think the answer [B] is right. Because at beginning of suction stroke exhaust gases are just delivered and hence temperature must be high and as suction happens atmospheric air comes in contact with engine cylinder and temperature reach it lowest value.

I believe option B is more appropriate, because at the beginning of the suction stroke high temperature exhaust gas had just omitted hence the chamber will be still hot. By the end of suction stroke chamber is filled with fresh air which is atm temp.