1. Pressure change across a 1-d deflagration From the mass and momentum equations for a 1-d wave, find the fractional pressure change P1P1P2 Across a stoichiometric, methane-air flame as a function of the reactant density (1), laminar flame speed (SL), a pseudo "thermal energy" of the reactants defined to be R1T1, the temperature ratio across the flame (T2/T1), and the molecular weight ratio across the flame (MW2/MW1). You may assume the gases are ideal in your analysis. Using your expression, then determine the pressure change across a stoichiometric methane-air flame with reactants at 300K and 1atm. ( SL=0.37m/sec,Tad=2220K) Hint: start from momentum equation to solve the pressure change cross the flame, use gas eq (assume methane-air mixture at 300K and 1atm ) to estimate some values to help the simplification of the relationship