$(40$ pts$.)$ Using a combination of correlations and simplified theory, estimate propane$-$air flame thicknesses for $P=1,10,$ and $100$ atm for $=1$ and $T_u=300K.$

$(20$ pts$.)$ A premixed propane$-$air mixture emerges from a round nozzle with a uniform velocity of $70c\frac{m}{s}.$ The laminar flame speed of the propane$-$air mixture is $32c\frac{m}{s}.$ A flame is lit at the nozzle exit. What is the cone angle of this flame? Is it constant?