The investigation of vibroacoustical activity of the combined fuel pump

A theoretical and experimental investigation of the fuel pump for a gas turbine engine is described. The combined pump consists of blade and gear units. Under the pump exploitation the graphite bearing of the blade unit was being destroyed due to the high level of vibroacoustical loading at the resonant working conditions. The complex dynamic model of the pump was created to estimate pulsation and vibration productivity of the pump. The mechanism and sources of intensive vibroacoustical stresses were identified. The complex test of the fuel system allowed us to define parameters of pulsing liquid, vibration of the pump (including natural frequencies), oscillation of torque and rotation of the driving shaft, and sound power of the pump. The test’s results have good coincidence with the modeling data and confirm the hypothesis regarding the reason for the bearing destruction. The facilities to decrease vibroacoustical stresses were proposed after analyzing the dynamical characteristics of the fuel system. The effectiveness of the facilities was proved by modeling and natural experiments. As a result of the research, vibration, pulsation, and noise activity of the pump were reduced significantly, and the defect connected with the destruction of the bearing was eliminated.