139x Filetype PPTX File size 0.12 MB Source: blanchard.ep.wisc.edu
Introduction Sensitivity Analysis = the study of how uncertainty in the output of a model can be apportioned to different input parameters Local sensitivity = focus on sensitivity at a particular set of input parameters, usually using gradients or partial derivatives Global or domain-wide sensitivity = consider entire range of inputs Typical Approach Consider a Point Reactor Kinetics problem 1.8 =0.08 dP 1.7 increased by 50% 0 P(t)C(t) dt 1.6 dC 1.5 P(t) C(t) ) t1.4 ( dt P P(0) P 1 1.3 0 1.2 P C(0) 0 1.1 1 0 0.5 1 1.5 2 2.5 3 time (s) Results P(t) normalized to P0 Mean lifetime normalized to -3 baseline value (0.001 s) 3 x 10 t=3 s 2 ) 1 t ( P n i e g n 0 a h c e v i t a l-1 e r -2 -3 -0.1 -0.05 0 0.05 0.1 0.15 relative change in Results P(t) normalized to P0 Mean lifetime normalized to baseline value (0.001 s) 0.02 0.015 t=0.1 s 0.01 ) t ( P n i 0.005 e g n a h c 0 e v i t a l e r-0.005 -0.01 -0.015 -0.1 -0.05 0 0.05 0.1 0.15 relative change in Putting all on one chart – t=0.1 s 0.025 0.02 0.015 ) 0 t ( 0.01 P n i n o 0.005 i t a i r a v 0 s s e l -0.005 n o i s n e -0.01 m i d -0.015 -0.02 -0.025 -0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 dimensionless variation in input variable
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