Download Thermodynamics Exam 2 - ENSC 2213 - Prof. Arland Johannes and more Exams Thermodynamics in PDF only on Docsity! DISCUSSION SECTION # NAME ENSC 2213 THERMODYNAMICS FALL 2011 – EXAM 2 Instructions for taking examinations 1. Do not open the exam until you are told to do so. When told to start, put your name on each page and your discussion section number in the space provided above. 2. This test is open book, open syllabus, roadmap and two page of notes. 3. Do not exchange anything with your neighbors during the exam. 4. Show all work. Use diagrams, show control volumes as needed and define your system! Identify reference points clearly and unambiguously. Write equations in variable form before entering numbers. Answers that are unsupported will not be accepted. Cross out (clearly) or erase all work that you do not want to be graded. 5. All answers should be given to a reasonable degree of precision - usually to three significant figures. Excessive or insufficient precision will be penalized. 6. Every answer must include correct units. 7. Identify your final answer by boxing it in. 8. The examination will be stopped promptly at the appropriate time. Stop writing when told to do so and pass the exam papers towards the aisle immediately. 9. Unless you finish prior to 10 minutes before the exam finish time, please remain in your seat until all exam papers have been picked up. 10. The number in parentheses in each problem indicates the number of points for that problem. Note that problems may not be of equal weight. ENSC 2213 Thermodynamics NAME EXAM 2 / 10-21-11 2 (25) Problem 1. Each of the five parts below is a separate problem. Please calculate the appropriate quantity. You do not have to draw a picture and the system is always the fluid. a) Propane is enclosed in a container at 20C. If the specific volume of the propane in the container is 0.03 m3/kg, determine the quality. b) Determine the specific volume of ammonia in ft3/lbm at a pressure of 20 lbf/in 2 and a temperature of 50F. c) Determine the specific volume in ft3/ lbm of propane at 131F and 20 psia. d) Determine the internal energy in kJ/kg of water at a pressure of 23.4 bar and a temperature of 417C. e) Determine the enthalpy in kJ/kg of water at a pressure of 25 bar and a temperature of 80C. ENSC 2213 Thermodynamics NAME EXAM 2 / 10-21-11 5 ENSC 2213 Thermodynamics NAME EXAM 2 / 10-21-11 6 (25) Problem 4. You have been asked to finish the design of a steam turbine. The design calls for steam to flow into the turbine through an inlet pipe having a diameter of 0.2 m. At the inlet, the velocity is 100 m/s at conditions of 14 MPa and 600C. The steam exits the turbine through a pipe of diameter 0.8 m at conditions of 500 kPa and 180C. You may assume that kinetic and potential energy changes are negligible. Determine, a) the mass flow rate of the steam flowing through the turbine in kg/h. b) the velocity of the steam at the exit in m/s. c) assuming the turbine operates with no heat loss to the surroundings, calculate the power output of the turbine in kW. ENSC 2213 Thermodynamics NAME EXAM 2 / 10-21-11 7
