THERMODYNAMICS ASSIGNMENT

EC41FA2

Submitted to:Engr. Joel Gatchalian

Date Submitted:July 28, 2011

NAMES:

Almarez, MelvinBalisi, Baby LiezelClaravall, Justine Jarabe, Crystel AnnJose, Michell Anne Mercene, Ma. Laeka Ann Sarmiento, Czarina JeanTalavera, Jayson D.

1. Assuming that there are no heat effects and no frictional effects, find the kinetic energy and speed of a 3220-lb body after it falls 778 ft from rest. Start with the steady flow equation, deleting energy terms which are irrelevant.

Solution:

2. A reciprocating compressor draws in 500 cubic feet per minute of air whose density is 0.079 lb/cu.ft and discharges it with a density of 0.304 lb/cu.ft. At the suction, p1=15 psia; at discharge, p2= 80 psia. The increase in the specific internal energy is 33.8 Btu/lb and the heat transferred from the air by cooling is 13 Btu/lb. Determine the work on the air in Btu/min and in hp. Neglect change in kinetic energy.

Solution:

3. Steam enters a turbine with an enthalpy of 1292 Btu/lb and leaves with an enthalpy of 1098 Btu/lb. The transferred heat is 13 Btu/lb. What is the work in Btu/min and in hp for a flow of 2 lb/sec?

Solution:

4. A thermodynamic steady flow system receives 4.56 kg per min of a fluid where p1=137.90 kPa, v1=0.0388 m3/kg, Ѵ1=122 m/s, and u1=17.16 kJ/kg. The fluid leaves the system at a boundary where p2=551.6 kPa, v2=0.193 m3/kg, Ѵ2=183 m/s and u2=52.80 kJ/kg. During the passage through the system the fluid receives 3000 J/s of heat. Determine the work.

Solution:

5. Air flows steadily at the rate of 0.5 kg/s through an air compressor, entering at 7 m/s speed, 100 kPa pressure and 0.95 m3/kg specific volume, and leaving at 5 m/s, 700 kPa, and 0.19 m3/kg. The internal energy of the air leaving is 90 kJ/kg greater than that of the air entering. Cooling water in the compressor jackets absorbs heat from the air at the rate of 58 kW. Compute the work in kW.

Solution:

6. In a steady flow apparatus, 135 kJ of work is done by each kg of fluid. The specific volume of the fluid, pressure, and speed at the inlet are 0.37 m3/kg, 600 kPa, and 16 m/s. The inlet is 32 m above the floor, and the discharge pipe is at the floor level. The discharge conditions are 0.62 m3/kg, 100 kPa, and 270 m/s. The total heat loss between the inlet and discharge is 9 kJ/kg of fluid. In flowing through this apparatus, does the specific internal energy increase or decrease, and by how much?

Solution:

7. Steam enters a turbine stage with an enthalpy of 3628 kJ/kg at 70 m/s and leaves the same stage with an enthalpy of 2846 kJ/kg and a velocity of 124 m/s. Calculate the work done by the steam.

Solution:

Group Pictures:

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