1. ME 475/675 Introduction to Combustion Lecture 34

2. Announcements Integrated BS/MS Degree http://www.unr.edu/engineering/academics/accelerated Term Project Add 2% to HW http://wolfweb.unr.edu/homepage/greiner/teaching/MECH.475.675.Combustion/TermProjectAssignment.pdf

3. Midterm 2 Scaled = 10xSqrt(Raw) Scaled average = 82

4. Flame Quenching, Mixture Flammability, Ignition

5. Cold Wall Quenching Quenching distance d Smallest dimension d that allows flame to pass Experimentally determined by shutting off flow of a premixed stabilized flame d tube = (1.2 to 1.5) d tube d d

6. Simplified Quenching Analysis for a slot b=2 b>2

7. Quenching will take place when b=2 b>2

8. Data, Table 8.4 page 291

9. Example 8.4, page 290 Turn in next time for EC

10. Flammability Limits

11. Example 8.5, p 294 (turn in next time for EC) A full propane cylinder from a camp stove leaks its contents of 1.02 lbm (0.464 kg) into a 12’x14’x8’ (4.66 m x 4.27 m x 2.44) room at 20C and 1 atm. After a long time, the fuel gas and room are well mixed. Is the mixture in the room flammable?

12. Ignition

13. Energy to bring critical volume to T b