This is an example of the multiphysics capabilities available in BEARCLAW. Two sets of conservation laws are solved simultaneously. The Euler equations of compressible gas dynamics are solved within the shock tube. The shock tube walls are assumed to be elastic strings on which the wave equation is solved. The pressure in the fluid gives a pressure loading on the shock tube walls. The motion of the shock tube walls influences the motion of the gas. A fluid-structure interaction problem with rich dynamics is thus obtained. The tube walls are pinned at the ends and at the middle where the initial discontinuity is set up. The two walls have different elastic wave velocities and linear masses. Various end boundary conditions for the gas gives rise to markedly different behavior.
An interesting aspect of the problem is the transfer of some of the initial energy of the gas to the elastic walls and then back again to the gas leading to successive deceleration and acceleration of the fluid flow.
Animation of Mach field (1.4 MB GIF file)
Animation of moving mesh, colored according to local Mach number (1.7 MB GIF file)
Animation of Mach field (1.4 MB GIF file)
Download directory in compressed tar file format
(Note: Please unpack the tar file in your CLAW home directory.)
