Textbook in PDF format Modeling of Combustion Systems provides accessible instruction for the operator or engineer to model combustion responses such as NOx, CO, flame dimensions, or heat flux as a function of input factors, such as excess oxygen, firing rate, furnace temperature, and fuel type. Retaining the emphasis on practical semiempirical modeling of boilers, process heaters, and reactors, such as ethylene cracking units and ammonia and hydrogen reformers, the second edition expands the approach to include combustion air fans and representation of complex models (direct numerical simulations or computational fluid dynamics) in concise forms. It also shows how to design experiments to collect the most data with the fewest experiments and model real unit behavior with engineering accuracy