Question

In a cylinder/piston arrangement, air is compressed in a reversible polytropic process to a final state...

In a cylinder/piston arrangement, air is compressed in a reversible polytropic process to a final state of 800 kPa, 500 K. Initially air is at 110 kPa and 25oC. During the compression process heat transfer takes place with the ambient maintained at 25oC. Assume air as an ideal gas (R =0.287 kJ/kg) and has constant specific heats of Cp = 1.004 kJ/kgK and Cv = 0.717 kJ/kgK. If the mass of air in the cylinder is 0.1286 kg, determine

a) the polytropic exponent n,

b) the final volume of the air,

c) the work done by the air,

d) the heat transfer and

e) the total entropy generation for the process.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A piston cylinder device contains air with a volume of 0.05 m3 at 25oC and 100...
A piston cylinder device contains air with a volume of 0.05 m3 at 25oC and 100 kPa pressure. The gas is now compressed to a final temperature of 95oC at 250 kPa. This compression is polytropic and follows PVn=constant. a. Determine how much boundary work was added to the gas [in kJ] b. How much heat was added or removed from this system during this process? [in kJ]
A piston cylinder device contains 0.15 kg of air initially at 2 MPa and 350 C....
A piston cylinder device contains 0.15 kg of air initially at 2 MPa and 350 C. First, the air expands isothermally to a pressure of 500 kPa. Then, it is compressed polytropically back to the initial pressure (2 MPa) with a polytropic exponent of 1.2. Find the work performed or introduced by or to the air for each process. Express it both times in kJ.
A 0.2 m3 piston-cylinder initially contains 400 K air. A heavy frictionless piston maintains a pressure...
A 0.2 m3 piston-cylinder initially contains 400 K air. A heavy frictionless piston maintains a pressure of 500 kPa abs. Then, a weakness in the cylinder wall blows out and creates a hole. Air escapes through the hole until the piston drops far enough to cover the hole. At that point, the volume is half the initial volume. During this process, 75 kJ of heat is transferred to the 100 kPa, 300 K surroundings. Using Cp = 1.005 kJ/kg-K and...
Air was compressed (polytropic process) from p1= 100kPa and T1= 293Kto p2= 0.3MPa and v2=0.2803m3/kg. The...
Air was compressed (polytropic process) from p1= 100kPa and T1= 293Kto p2= 0.3MPa and v2=0.2803m3/kg. The isentropic exponent of the gas and specific gas constant are 1.4 and 287 J/(kgK), respectively. Determine (a) polytropic exponent, (b) heat and work of this process, (c) change of internal energy, (d) change of entropy of air,if mass of air is 2kgand air can be treated as ideal gas.Additionally,(e) draw the process on the p-v and T-s diagrams.You can round temperature to one decimal...
Air expands in a polytropic process (n = 1.35) from 2 MPa and 1200 K to...
Air expands in a polytropic process (n = 1.35) from 2 MPa and 1200 K to 150 kPa in a piston/cylinder.   Determine per unit mass of air the work produced and the heat transferred during the expansion process in kJ/kg.
Steam, initially at 700 lbf/in.2, 550°F undergoes a polytropic process in a piston–cylinder assembly to a...
Steam, initially at 700 lbf/in.2, 550°F undergoes a polytropic process in a piston–cylinder assembly to a final pressure of 2200 lbf/in.2 Kinetic and potential energy effects are negligible. Determine the heat transfer, in Btu per lb of steam, for a polytropic exponent of 1.4, (a) using data from the steam tables. (b) assuming ideal gas behavior.
5 kg of air in a piston cylinder assembly undergoes a Carnot power cycle. Heat is...
5 kg of air in a piston cylinder assembly undergoes a Carnot power cycle. Heat is received at temperature?1=727°C and rejected at ?3=27°C.During the heat input process, the pressure changes from ?1=1200kPa to ?2=900kPa, respectively. Assume the air behaves as an ideal gas with constant specific heats. Determine: a.pressures [kPa] at beginning and end of the isothermal heat rejection process (?3,?4) b.heat transfer from high temperature source [kJ] c.thermal efficiency d.net work output for cycle [kJ]
Your new engine design consists of a piston cylinder arrangement. The engine operates with mostly air...
Your new engine design consists of a piston cylinder arrangement. The engine operates with mostly air and a small amount of fuel. The system undergoes a cycle. The initial Pressure and temperature are p1= 1bar and T1= 27°C. The system undergoes a power cycle consisting of the following process: Process 1-2                         constant volume to a pressure, P2 of 4 bars Process 2-3                         expansion of pv=constant Process 3-1                         constant-pressure compression Draw the system and pv diagrams If P2 is 4...
Air in a closed piston cylinder device is initially at 800 K and at 250 kPa....
Air in a closed piston cylinder device is initially at 800 K and at 250 kPa. The air undergoes a process until it is at 2200 K and at 750 kPa. What is the change in the air's specific entropy during this process (kJ/kgK)?
A mass of one kg of water within a piston–cylinder assembly undergoes a constant-pressure process from...
A mass of one kg of water within a piston–cylinder assembly undergoes a constant-pressure process from saturated vapor at 500 kPa to a temperature of 260°C. Kinetic and potential energy effects are negligible. For the water: a) Evaluate the work, in kJ, b) If the work is 30 kJ, evaluate the heat transfer, in kJ, c) If the heat transfer is negligible, evaluate the entropy production in kJ/K d) Determine if the process is reversible, irreversible, or impossible.