ME 475/675 Introduction to Combustion Lecture 37

Announcements HW16 Ch. 9 (8, 10, 12) Due ? Term Project (3% of grade) Nothing dangerous please! Proposals due Today by 5 PM (part of project grade) them to Rachel Green After review we may recommend some changes Indicate on proposal if you want 2% added to HW or Final You may need to resubmit your proposal if you didn’t include this before I will assume it will be added to HW unless you request otherwise Instructions: Must meet with Rachel to discuss proposal before the end of day Wednesday 26 th Times to meet with Rachel Green about projects Wednesdays, 11-3 pm HREL 306 Fridays, 1-3pmHREL 306 Mondays, 11-4 pm HREL 306 Schedule other times by ing

Ch. 9 Laminar Diffusion Flames (not premixed)

Variables and Boundary Conditions

Conservation Equations (radial coordinates, p. 314)

Dimensionless Similarity Variable

Jet “half” radius Slow Fast

Fuel Mass Fraction

Example 9.1 A jet of ethylene (C 2 H 4 ) exits a 10-mm-diameter nozzle into still air at 300 K and 1 atm. Compare the spreading angles and axial locations where the jet centerline mass fraction drops to the stoichiometric alue for initial jet velocities of 10 cm/s and 1.0 cm/s. The viscosity of ethylene at 300 k is 102.3x10 -7 Ns/m 2. This is a model for flame length