How to simulate the CO and CO2 concentration? Is balanced chemical equation is enough or some simulated pressure and temperature data vs Crank angle is also needed just like NOx. Can any one please share me some good article in which simulation is explain step by step?
You generally cannot determine the CO/CO2 split from a balanced chemical reaction alone since there will be other fuel-rich species whenever there is CO, and the elemental balances of C H and O are insufficient to determine the amounts of CO, CO2, H2, H2O, O2, N2 and possibly CH4. There are too many unknowns for the number of equations.You probably realize that at peak combustion temperatures, CO2 and H2O decompose to form some CO and H2, even in the presence of O2. Therefore, a simple element balance under fuel-lean conditions (assuming there is no CO or H2 or other fuel-rich species) is not accurate. Furthermore, if you are interested in chemical details, the major radical species O, H, OH, N and CH or soot precursors, such as C2Hx, or pollutants, such as NO, NO2 etc. you are in worse shape still. A chemical equilibrium calculation, which supplements the element balances with thermodynamic equilibrium calculations, is generally sufficient to estimate the major stable species. If you also need radicals, you will need to use a chemical kinetics.
Hello Anas Rao,
this is indeed a very interesting topic. As professor Baxter wrote, the composition of the exhaust gases of an IC engine is function of several factors, including air-fuel ratio, the fuel composition, temperature, pressure, etc. I would suggest you to begin chosing some operation points (temperature, pressure, stechiometry) and then calculate the chemical equilibrium for those conditions. You can use the CEA NASA code, that is on line available: https://www.grc.nasa.gov/WWW/CEAWeb/
The CEA code already has some fuels in its library, like Jet A and the main hydrocarbons (methane, propane, iso-ocatne, n-heptane, etc). It is a very helpful tool.
Simulation of these two emissions concentration during combustion in I.C. Engines is really hard to achieve because the process itself is time and space dependent. The concentrations of fuel and air are different at different zones in the combustion chamber specially if the engine is a CI engine. One thing you can do is to keep some of the operating parameters constant like speed,load,fuel consumption injection timing ...etc and then take measurements of these constituents in the exhaust and repeat by changing one of the.operating parameters and then you may come up with an empirical correlation relating the concentrations with some engine operating parameters and then you can compare these results with your theoretical model.
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