18.306 Lecture 14 - Tue 2021 04 13 - Virtual % ============================================================================== Example: "Shock structure" Shock as a traveling wave for u_t + Q(u)_x = (nu*u_x), nu = nu(u) > 0. Q convex or concave. Show it satisfies Rankine-Hugoniot and entropy. Show it gives shock in limit nu \to 0 Example: Show "energy" decreases for u_t + Q(u)_x = (nu*u_x), nu = nu(u) > 0. Show that, for traveling wave, energy loss is independent of nu \to 0. Compute energy loss for shock solution of u_t + Q(u)_x = 0. #031 SKIP, but make connection with last point [u^2 is dissipated by shock]. #032a SKIP #032b Source term does not affect shock conditions. #033a Weak derivatives and weak solutions. Examples to do: u_t + (0.5*u^2)_x = -a*u with triangle initial condition. u_t + (0.5*u^2)_x = 0 Formation of S and N waves from compact data. % % ============================================================================== EOF