Project III Premixed Flames OBJECTIVE: Use the Chemkin and Gaseq software to study premixed methane/hydrogen-air combustion waves. 1) 2) 3) 4) Determine and discuss the flame structure for a methane-air flame at 300K, 1 atm. Examine the flame “structure” and discuss the accuracy of the two zone structure assumed in the flame speed derivation in class. Also, discuss the other assumptions made in the class derivation in light of the computed results. Determine the dependence of the flame speed, flame thickness, and ratio of reaction zone to preheat zone thickness upon H2/CH4 ratio ranging from pure H2 to pure CH4. Fix the same adiabatic flame temperature as in (1); i.e., you will need to run each case at a different stoichiometry to fix flame temperature. Analyze the results and suggest the mechanism(s) and key physics controlling these results. Using the GasEQ software, determine the corresponding C-J detonation wave speed for the same parameter set. Discuss the results and compare and contrast the dependence of the wave pressure ratio upon the varied parameter. Extra Credit (up to +10 pts): 1) It is often of interest to obtain some quantitative assessment of the rate of heat release at a certain point in a flow field. However, the rate of heat release is difficult to measure directly. Based on the above results, is it possible to estimate (quantitatively) the rate of heat release by measuring the concentrations of certain radicals (e.g., can the rate of heat release be related to the CH concentration)? If so, which radicals serve as the best markers of heat release? Chemkin You will need to use the Chemkin software package for these calculations. PREMIX models a one-dimensional premixed flame. The Chemkin software is available in the AE Computer Lab (Knight 3rd floor). Every on-campus student in class has an account on these networked computers; instructions for logging in are posted on the computer room door. The room is unlocked during the day. Your buzz card should give you access to the building and the computer room at other times. Please note that you only have write access to your own folder. So you will need to set your working directory to some subfolder of your own user folder.