Research on centrifugal compressor disk containment of auxiliary power unit

To investigate the centrifugal compressor disk containment of auxiliary power unit (APU) in gas turbine, research on specific compressor is conducted in combination of simulations and tests. Nonlinear explicit finite element analysis of tri-hub fragments impacting containment assembly is carried out using LS-DYNA. Impacting characteristics in each period are discussed. Strength of the outer cover, the back shroud and the connecting bolts between them is further studied through simulation. The results show that the fragments interact with the outer cover and the back shroud both in rotating plane and axial direction. The internal energy is mostly composed of the strain energy of the impeller. Insufficient strength of each component leads to an uncontained result. Potential failure modes are discussed. Verification tests on high-speed spin tester revealing both contained and uncontained cases have been conducted and showed that the outer cover, the back shroud and the connecting bolts between them all play a significant role to containment. Adequate strength of these components is essential. Otherwise the outer cover will detach away and the back shroud will be damaged.