Numerical Simulation Of Imcompletely Combustion Process Of Nanopatrticles Prepared By Flame CVD Method

Hongyong Xie and Wei Zhang etc. had prepared carbon black through imcomplete combustion method. They used propane and air as materials and changed the ratio of fuel air in preparing carbon black in different operational conditions. Cabon black nanopatrticles intermingled into TiO₂ nanopatrticles that make TiO₂ have more catalysis capability. On the basis of the experimental work, this paper simulates complete and imcomplete combustion process of propane and air to provide physical insights for the experimental work.There have been several decades for numerical simulation of turbulent combustion, and the research of premix and diffusion combustion is also quite extensively. But the simulation of detailed chemical mechanism has only sloved laminar flow combustion. This paper uses self-define scalar method to simulate turbulent combustion with detailed rection mechanism of propane from Casimir. Program the chemical reaction rates of composition transfer equation and modify the source term of Energy.Because abundant acetylene have been detected in combustion, so we adopt the hypothesis of acetylene leading to carbon black. Simulate the nucleation and surface growth processes of carbon black and analyze them what effects dominate carbon balck growth process.This paper using self-define scalar method simulates combustion process. The simulation progress is divided into the following sections.(1)Simulation of flameUsing commercial CFD-code Fluent, the simulation of gas velocity and temperature profile in propane/air turbulent diffusion flame for carbon black nanoparticle production have been detailed performed with three different k-ε turbulent models. The results show that standard k-εturbulent model at non-equilibrium wall fuction is priority to the other models. Also simulating the other there conditions, the results are consistent with experiments.(2) Simulation of propane combustion process by self-define scalar methodThis method defines reaction compositions as self-define scalars in Fluent, computes the mass, momentum, energy and composition conservation equations through defining chemical reaction as source term, and modifies the energy equation by the energy change caused by chemical reaction. Compare this method with one step reation model (EDM) and validate the correctness of this method and the mechanism. Comparisons have been made on flame length, temperature, and C₂H₂ distribution between simulated and experimental data.(3) Simulation of carbon black formation process by self-define scalar method...