MEEN 315 PRINCIPLES OF THERMODYNAMICS SPRING 2017 Homework Cover page Student Last Name Student First Name UIN Section Select 204 OR 504 HW Date Submitted 4 Grading Completion All problems attempted Quality Neatness clarity legible Accuracy Accuracy of selected problem s Cover page this page attached on the top and all pages stapled together Total 10 points Max Score 4 1 4 1 Your Score 10 This cover page should be completed and stapled to the top of your homework solution MEEN 315 PRINCIPLES OF THERMODYNAMICS SPRING 2017 Homework Assignment 2 Due Feb 14 2017 At the beginning of the class Topics covered Properties and processes for pure substances Problem 1 Determine the missing properties for water H2O for each state given Show your three step decision process i e 1 list two known properties 2 determine the phase 3 look up properties from the correct table and show all calculations made for each case Fill in the table with your final answers Phase quality T Phase name X F X 1 0 230 450 212 400 P psia v ft3 lbm u Btu lbm h Btu lbm 200 2 0 1000 Problem 2 Determine the missing properties for refrigerant R134a CF3CH2F for each state given Show your three step decision process i e 1 list two known properties 2 determine the phase 3 look up interpolate properties from the correct table and show all calculations made for each case Fill in the table with your final answers Phase quality T Phase name X C Sat vapor P kPa 425 180 800 2000 v m3 kg u kJ kg h kJ kg 0 1224 305 70 Problem 3 A rigid sealed cylinder is filled completely with 100 lbm of pure water at 70 F and atmospheric pressure Determine a the volume of the tank ft3 Later a pump is used to extract 15 lbm of water from the cylinder The water remaining in the cylinder eventually reaches thermal equilibrium with the surroundings at 70 F Determine b the final specific volume and c the final pressure psia Initial State 100 lbm H2O 70 F 1 atm Final State m2 m1 15 lbm 70 F MEEN 315 PRINCIPLES OF THERMODYNAMICS SPRING 2017 Problem 4 A piston cylinder apparatus contains 5 kg of refrigerant R 134a at 200 kPa and 20 C The piston is slowly pressed downward by a force applied to the piston The compression process is slow such that the temperature of the system remains constant At some point the system becomes nearly incompressible regardless of the amount of applied force For the process a determine the initial and final volume m3 c determine the final pressure kPa minimum c draw the process on a P v diagram labeling the initial and final states and including the vapor dome on the diagram Initial State Final State piston R134a Applied Force F 200 kPa 20 C piston 20 C Problem 5 A rigid tank contains a partition that divides the tank into two sections each having a volume of 2 ft3 The left side contains 1 5 lbm of refrigerant R 134a at a pressure of 50 psia and the right side contains 2 lbm of refrigerant R 134a at 30 psia The partition is then ruptured and the contents are allowed to mix Heat transfer occurs with the surroundings until the entire tank contents reach a new equilibrium temperature of 60 F For this process determine a the initial temperature of the left and right sections F b the final pressure in the tank psia Initial State 2 ft3 1 5 lbm R134a 50 psia Partition 2 ft3 2 lbm R134a 30 psia Final State 60 F 4 ft3 3 5 lbm
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