Analysis of the Water Hammer Effect and Structural Response Characteristics in the Fire-Resistant Oil System of Gas Turbine Units

In gas turbine fire-resistant oil systems, valve actuations induce transient pressure fluctuations and the water hammer effect, causing pressure oscillations and structural vibrations. This study uses a coupled CFD and transient structural simulation to analyze the effects of different valve strategies on pressure wave propagation and structural response. Results show that a higher valve opening rate leads to a more significant water hammer effect, increasing structural deformation and stress. The maximum equivalent stress was verified at 201.9 MPa, maintaining a 30% safety margin and meeting American Society of Mechanical Engineers (ASME) B31.3 requirements. Finally, a “slow-fast-slow” (S-shaped) valve strategy is proposed to significantly improve the system’s pressure response characteristics, providing theoretical and engineering guidance for safe operation.