Numerical approximation of Knudsen layer for the Euler-Poisson system Fréderique Charles, Nicolas Vauchelet, Christophe Besse, Thierry Goudon, Ingrid Lacroix–Violet, Jean-Paul Dudon and Laurent Navoret ESAIM: Proc., 32 (2011) 177-194 Published online: 03 November 2011 DOI: 10.1051/proc/2011020