Tech Briefs

FSI Analysis of a Breaking Pipe

The 3D fully coupled FSI analysis given here was performed by a Nuclear Power Station using ADINA.

The animation shown above depicts the velocity vectors and pressure contours during the failure of the main steam pipe of a boiling water nuclear reactor. The geometry as shown is a section of the complete pipe, with more details provided in the schematic below. The fluid domain is composed of the region inside and outside the pipe. The vapor is modeled as a high-speed compressible flow. The pipe is modeled as an elastic isotropic material.

The pressure within the pipe is initially at 7 MPa and the steam temperature is 559 K. Outside the pipe, the pressure is initially at 0.1 MPa. After the pipe breaks, the steam flows out of the pipe causing a sudden drop in pressure that propagates rapidly in both directions along the pipe. These results are used to assess the integrity of the pipe upstream and downstream. The time history of the pressure wave propagation into the reactor pressure vessel is also useful.

For more information on ADINA FSI, please refer to our page on fluid-structure interaction.