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We want study the damaging effects of the violent collapse of two-phase structures on the functioning of hydromechanics componants and energy systems (turbopumps, fuel injectors, propellers...). Indeed the implosion of gas bubbles appearing within these components generates high-amplitude peaks of pressure due to the propagation and interference of waves as well as a phenomenon of high-speed micro-jet. These phenomena can degrade the performances and damage the solid walls.

In a first study, a weak fluid-structure coupling was set up on the basis of the codes SCB (two-phase code, finite volumes) and FreeFem (mechanical code, finite elements). The considered case consists in a gas bubble impacted by a normal shock wave.

The objectives of the internship are:

  1. to improve the numerical integration inside the solid (second order scheme);
  2. to test various laws of behavior for the material allowing to describe the plastic deformation (elasto-plastic law, Johnson-Cook, etc);
  3. to evaluate a compressible formulation where the density in the solid varies.

The response of the solid to the bubble collapse will be studied. The effect of the distance between the bubble and the wall will be investigated for 2D cases.