This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 7.2. ADIABATIC, ISOCHORIC KINETICS 277 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.2 0.4 0.6 0.8 1.0 1.2 1.4 * 1 Figure 7.14: 1 versus for ignition problem. For our system with = 20 and q = 10, we estimate the dimensionless ignition time as i = exp 20 (20)(10) = 2 . 42583 10 6 . (7.359) This is a surprisingly good estimate, given the complexity of the problem. Recall the nu- merical solution showed ignition for 2 . 7 10 6 . In terms of dimensional time, ignition time prediction becomes t i = exp a q , (7.360) = 1 a parenleftbigg RT o E parenrightbigg parenleftBigg c v T o h o T o ,A h o T o ,B parenrightBigg exp parenleftbigg E RT o parenrightbigg . (7.361) Note the ignition is suppressed if the ignition time is lengthened, which happens when he activation energy E is increased, since the exponential sensitivity is stronger than the algebraic sensitivity, the energy of combustion ( h o T o ,A h o T o ,B ) is decreased because it takes longer to react...
View Full Document
This note was uploaded on 11/26/2011 for the course EGN 3381 taught by Professor Park-sou during the Fall '11 term at FSU.
- Fall '11