MIT 2 141 - WORK-TO-HEAT TRANSDUCTION IN THERMO-FLUID SYSTEMS (27 pages)

Previewing pages 1, 2, 3, 25, 26, 27 of 27 page document View the full content.
View Full Document

WORK-TO-HEAT TRANSDUCTION IN THERMO-FLUID SYSTEMS



Previewing pages 1, 2, 3, 25, 26, 27 of actual document.

View the full content.
View Full Document
View Full Document

WORK-TO-HEAT TRANSDUCTION IN THERMO-FLUID SYSTEMS

74 views


Pages:
27
School:
Massachusetts Institute of Technology
Course:
2 141 - Modeling and Simulation of Dynamic Systems

Unformatted text preview:

WORK TO HEAT TRANSDUCTION IN THERMO FLUID SYSTEMS ENERGY BASED MODELING IS BUILT ON THERMODYNAMICS the fundamental science of physical processes THERMODYNAMICS IS TO PHYSICAL SYSTEM DYNAMICS WHAT GEOMETRY IS TO MECHANICS WHY SHOULD WE CARE ABOUT THERMAL PHENOMENA they can profoundly influence dynamic behavior Mod Sim Dyn Syst Work to heat transduction page 1 EXAMPLE A CLOSED BICYCLE PUMP work in air sealed outlet COMPRESSIBLE GAS AIR IN A CLOSED CONTAINER WITH VARIABLE VOLUME Compress the gas and it gets hot When the gas is hotter than its surroundings the temperature gradient induces heat flow Mod Sim Dyn Syst Work to heat transduction page 2 THIS IS ANOTHER FORM OF ENERGY TRANSDUCTION mechanical work to compress the gas is converted to heat governed by the first law ENERGY TRANSDUCTION IS BILATERAL IT WORKS BOTH WAYS Heat the gas and its pressure increases If the pressure moves the piston to increase gas volume mechanical work is done Mod Sim Dyn Syst Work to heat transduction page 3 QUESTION If you do work on the gas can you get all of it back Answer No due to the second law Under what conditions is this energy loss significant How do we integrate this behavior with our previous models AT LEAST TWO DIFFERENT PHENOMENA ARE INVOLVED energy storage power dissipation Mod Sim Dyn Syst Work to heat transduction page 4 ENERGY STORAGE IN A COMPRESSIBLE GAS ENERGY IS ADDED TO OR TAKEN FROM THE GAS IN TWO FORMS mechanical work or heat MODEL THIS AS A MULTIPORT ENERGY STORAGE ELEMENT but of what kind Mod Sim Dyn Syst Work to heat transduction page 5 A RELEVANT STATEMENT OF THE FIRST LAW U Q W U internal energy of the gas Q heat added to the gas W work done by expansion of the gas Notation and sign convention are standard for engineering thermodynamics APPLY THIS ON AN INSTANT BY INSTANT BASIS USING ITS DIFFERENTIAL FORM dU dQ dW Mod Sim Dyn Syst Work to heat transduction page 6 ON THE MECHANICAL SIDE dW PdV P pressure V volume THE GAS BEHAVES AS A CAPACITOR ON THE



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view WORK-TO-HEAT TRANSDUCTION IN THERMO-FLUID SYSTEMS and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view WORK-TO-HEAT TRANSDUCTION IN THERMO-FLUID SYSTEMS and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?