1. ENGR-25_Prob_6-12_Solution.ppt 1 Bruce Mayer, PE Engineering-25: Computational Methods Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu Engineering 25 Prob 8-8 Solution Tutorial

2. ENGR-25_Prob_6-12_Solution.ppt 2 Bruce Mayer, PE Engineering-25: Computational Methods The Conduction Eqn  The General Equation:  Electricity → Ohm’s Law  Heat → Fourier’s Law [FlowRate] = [Conductance]·[PressureChange]

3. ENGR-25_Prob_6-12_Solution.ppt 3 Bruce Mayer, PE Engineering-25: Computational Methods The Conduction Eqn  The General Equation:  Fluids → Poiseuille's s Law  Diffusion → Fick’s Law [FlowRate] = [Conductance]·[PressureChange]

4. ENGR-25_Prob_6-12_Solution.ppt 4 Bruce Mayer, PE Engineering-25: Computational Methods U vs R  CONDUTANCE and RESISTANCE are simply INVERSES  So WWhat are the UNITS of “R19” Insulation?

5. ENGR-25_Prob_6-12_Solution.ppt 5 Bruce Mayer, PE Engineering-25: Computational Methods ANCE vs IVITY  ConductANCE from ConductIVITY: σ  G  ConductANCE from ConductIVITY: k  U th

6. ENGR-25_Prob_6-12_Solution.ppt 6 Bruce Mayer, PE Engineering-25: Computational Methods ANCE vs IVITY  ConductANCE from ConductIVITY: D  U D  Note that “IVITY” is a MATERIAL Property that is INdependent of material GeoMetry and/or Physical Size

7. ENGR-25_Prob_6-12_Solution.ppt 7 Bruce Mayer, PE Engineering-25: Computational Methods ANCE vs IVITY i.e.; “IVITY” is intrinsic or inherent to the NATURE of the Material and  “ANCE”, on the other hand, depends on “IVITY” and the Physical SIZE & SHAPE of the Material Object (W/m·K)

8. ENGR-25_Prob_6-12_Solution.ppt 8 Bruce Mayer, PE Engineering-25: Computational Methods P 8-8

9. ENGR-25_Prob_6-12_Solution.ppt 9 Bruce Mayer, PE Engineering-25: Computational Methods

10. ENGR-25_Prob_6-12_Solution.ppt 10 Bruce Mayer, PE Engineering-25: Computational Methods

11. ENGR-25_Prob_6-12_Solution.ppt 11 Bruce Mayer, PE Engineering-25: Computational Methods

12. ENGR-25_Prob_6-12_Solution.ppt 12 Bruce Mayer, PE Engineering-25: Computational Methods The MATLAB Code

13. ENGR-25_Prob_6-12_Solution.ppt 13 Bruce Mayer, PE Engineering-25: Computational Methods The Results

14. ENGR-25_Prob_6-12_Solution.ppt 14 Bruce Mayer, PE Engineering-25: Computational Methods Bar Chart  Most Temp-Drop Occurs Across the Insulation