Numerical modeling for soot formation procedure in laminar pressurized nonpremixed flames

The Full Transport Equation approach is one of the accurate methods to predict the laminar non-premixed flame with soot formation and radiation heat transfer, but this approach requires excessive computational costs in the case of detailed chemistry with soot evolution. On the contrary, the laminar flamelet model [1] has an advantage that separate fluid dynamics and gaseous chemical reaction by using flamelet equation and conserved scalar; mixture fraction in term of computational efficiency. However, the soot formation and radiation heat transport have long enough time scales compared to the reaction mechanism of gas species, so the original laminar non-premixed flamelet method is not suitable for controlling together due to the these different time scales. Thus, to overcome these disadvantages and make sure of the efficiency in laminar non-premixed flame with soot formation and radiation, we modified the transient flamelet model based on RIF (Representative Interactive Flamelet) concept [2] coupled with semi-empirical two equation soot model [3] involving nucleation, surface growth, oxidation and agglomeration. Therefore, the present soot model calculates soot mass fraction and soot number density in mixture fraction space by coupling the gas chemistry with soot formation. But, only reaction rates of soot mass fraction and number density are used for transporting soot in flow field. To validate the present model, numerical results including soot volume fraction and temperature are compared with experimental data [4].