PROBLEM OF THE WEEK - Mech: Thermal/Fluids NCEES Problem 530

Today we begin a new series we're calling the "Problem of the Week." Some problems that you will encounter while preparing for the PE Exam are trickier than others, and we're going after the those that seem to cause folks the most trouble. First, we'd like to challenge you to see if you can solve the problem on your own. But we won't leave you hanging! Dr. Tom and our instructors will provide you with a video of their recommended method of solving the problem.

We're going to start with Problem 530 in the 2016 NCEES Mechanical Practice Exam for Thermal and Fluid Systems (Problem 516 in the 2011 practice exam). This problem involves finding the efficiency of a steam turbine and is a classic problem in Thermodynamics, where the ideal expansion is isentropic.

HINT: The isentropic values of the exit conditions at point 2 are not available in the MERM steam tables, so use the Mollier diagram (entropy vs enthalpy) in the MERM instead. It is remarkable how accurate the Mollier diagram can be read.

Dr. Tom's Solution to NCEES TFS Problem 530 (Dr. Tom has also worked an alternate “Bonus” problem based on Problem 530. We recommend you check that video out too.)

DTC recommends that anyone taking the PE Exam purchase the NCEES Practice Exam for the exam they are taking. It is an essential exam review resource. https://account.ncees.org/exam-prep/

Begin your review for the October Civil PE Exam today! 

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