| OCR Text |
Show RHCN = (R N - Roxid - R red ) M HCN (15), where RN is the rate is the rate of nitrogen release from the fuel, M. is the molecular weight of species i, and R 'd' R d are the 1 . OXl re reaction rates for oxidation and reduction. 3. ROLE OF TURBULENT FLUCTUATION ON NO FORMATION. The kinetic mechanism of NO formation and destruction described In the above section all have been obtained from laboratory expeliments using either a laminar premixed flame or a shock tube where molecular-diffusion conditions are well defined. However, the flow in any practical combustion system is highly turbulent, which implies that temporal fluctuations in temperature and species concentrations will influence the characteristics of the flame; mean reaction rates calculated as reaction rates of averaged temperatures and concentrations can result in substantial errors. 3.1 P.D.F. APPROACH To predict NO levels, equations (4), (9), and (14) must be time integrated along streamlines in the solutions of the flow field. This implies extraction of Lagrangian information from a Eularian solution. This requires a highly resolved Eularian solution for reasonable accuracy which is computationally expensive. Instead, the conservation of the Inass fraction of NO, (m NO ) was considered (17) |
