ME 40 Thermodynamics

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ME 40Thermodynamics

• Professor Jeff Marshall
• 231A Votey Hall
• 656-3826 jeffm_at_cems.uvm.edu
• Office Hours TTh 9-10am

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Class Details

• Class website (use Internet Explorer)
• http//www.cems.uvm.edu/jeffm/me40/me_40a_ho
  me.html
• Lecture Notes download from website and bring
  to class
• Textbook - Thermodynamics An Engineering
  Approach, Çengel Boles, McGraw-Hill, 6th ed.
• Class attendance is mandatory

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Grading

• Homework (weekly) 20
• Midterm Exam 1 25 last week of Feb
• Midterm Exam 2 25 last week of March
• Final Exam 30 5/5/08 1145am 245pm
• Notes Exams 1 2 are tentatively scheduled for
  these periods. Pre-examination review sessions
  will be held prior to each examination at dates
  times to be decided.

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Class Topics

• Basic Concepts in Thermodynamics systems,
  temperature pressure, units, energy, energy
  transfer (work heat), first law, efficiencies
  (Chapters 1 2)
• Thermodynamic Properties of Pure Substances
  phases, change of phase, tables data
  interpolation, internal energy, enthalpy,
  specific heat, ideal-gases, equations of state,
  non-ideality (Chapter 3).
• First Law Analysis of Closed Systems boundary
  work, energy balances, internal energy, enthalpy
  specific heats of gases (Chapter 4)
• First Law Analysis for Open Systems
  steady-state/flow unsteady-state flow, analysis
  of simple engineering devices (Chapter 5).
• Second Law of Thermodynamics statements of
  second law, irreversibilities, heat engines,
  refrigerators heat pumps, Carnot cycles
  (Chapter 6).
• Entropy concept of entropy, Tds relationships,
  entropy change, isentropic
• processes (Chapter 7).
• Introduction to Gas Power Systems (Chapter 9
  Sections 9.1 through 9.8)
• Introduction to Vapor Power Systems (Chapter 10
  Sections 10.1 10.6)

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What is Thermodynamics?

• ?

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What is Thermodynamics?

• Literal meaning
• Thermo ----- heat
• Dynamics ---- force
• Modern meaning Thermodynamics is the study of
  conversion between different forms of energy.

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Examples?

• Mechanical ?
• Civil ?
• Electrical ?

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Approach to Problem Solving

• 1. Understand problem
• What are you supposed to solve for?
• List given conditions
• Draw sketch with labels
• 2. Plan solution approach
• State assumptions (are the assumptions
  reasonable or just convenient?)
• Develop a plan (approach) by which the problem
  may be solved
• 3. Obtain solution
• Derive or choose appropriate mathematical
  formulas
• Plug in numbers to appropriate equations AFTER
  ALL FORMULAS HAVE BEEN OBTAINED
• Check units by using a unit equation
• Report only significant digits
• Are results reasonable?

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Example
What is known?
What do you need to find?
Plug in numbers at end
Draw a picture
State assumptions
Is answer reasonable?
Do analysis using EQUATIONS