Research on the velocity shock and energy loss of T-junction and arc-juncton in aircraft hydraulic system

Two pumps supply oil in parallel in the large aircraft. Due to different frequencies of the pumps, the flow field at T-junction of two oil convergence remains unclear. In this paper, the flow field of T-junction pipe was analyzed at two working status using Shear Stress Transport (SST) model and Finite Volume Method (FVM) in ANSYS/CFX. Our simulation identified the variation law of velocity peak at T-junction and it is found that the eddy and velocity shock exists in the corner of the T-junction. Aiming at this problem, an arc-junction was designed to replace the traditional T-junction. Based on the simulation, the eddy disappeared and the maximum of velocity peak decreased than T-junction. However, the curvature radius of the arc is a key factor which affects the fluid confluence, so 8 series of ρ was tested to get the law of the variation of max velocity. The velocity shock and energy loss are two evaluated index, and through simulation the optimal ρ was got, it can be concluded that the velocity shock decreased when ρ increased and the energy loss reached the minimum value at ρ = 32.52mm.