Computational fluid dynamics investigation of a misaligned-phase parallel external gear pump

To clarify the flow characteristics of the misaligned-phase parallel external gear pump with different phases and rotational speeds, the flow pulsation and cavitation of the misaligned-phase parallel external gear pump under different working conditions were systematically studied by combining theoretical analysis with tridimensional numerical simulation. The flow pulsation characteristics of the misaligned-phase parallel external gear pump are analyzed. Compared with the same-phase gear pump, the flow pulsation of the misaligned-phase parallel external gear pump was reduced. When the phase angle is ϕ = π / z , the pressure and flow pulsations of the parallel gear pump are minimum, the flow pulsation is less than 1/4 of the same-phase gear pump. The relationship between cavitation and phase angle of the misaligned-phase parallel external gear pump is verified. When the rotational speed is different, with the increase in the rotational speed, the amplitude of the pressure fluctuation increases, and the effect of pressure pulsation overlapping and counteracting each other in the misaligned phase is more ideal. The flow does not fluctuate with the rotational speed and is only related to the phase angle, the cavitation is aggravated with the increase in the rotational speed.