Flow Field Simulation Analysis of High Pressure Gear Pump

Figure 3-30 shows the pressure contour of the outer motor's inlet oil passage in the high pressure gear pump. When the outer motor operates at 863r/min, the maximum pressure in the inlet oil passage reaches 6.000017MPa, with a gradual pressure reduction along the flow path. This pressure drop occurs because the selected pressure oil exhibits certain viscosity and internal friction. As the oil flows through the passage, friction between the oil and the pipe walls generates heat, resulting in pressure energy loss within the high pressure gear pump system.

Low-pressure regions appear at the perpendicular contact points between the oil inlet and the flow passage, as well as at the first oil outlet's perpendicular contact with the passage. These pressure variations are caused by collisions and mutual friction between fluid particles, which are more intense in areas where the flow passage changes direction. Due to the perpendicular nature of these contact areas, more heat energy is generated, leading to significant pressure energy loss. This indicates that the inlet oil passage design of the outer motor in the high pressure gear pump is not optimal and requires optimization in these specific regions.

Figure 3-32 illustrates the velocity vector distribution in the outer motor's inlet oil passage of the high pressure gear pump. The fluid distribution in the passage appears relatively uniform; however, significant velocity vector changes and sudden variations occur at the contact areas between the oil inlet and the triangular oil passage, as well as between the oil outlet and the triangular oil passage. These velocity perturbations in the high pressure gear pump are caused by changes in both the direction and flow area at these locations.

The altered flow conditions intensify collisions between oil molecules, resulting in sudden changes in velocity vectors and subsequent local pressure losses. These findings are critical for understanding energy dissipation mechanisms within the high pressure gear pump, as velocity perturbations directly impact overall efficiency and performance.

The velocity vector analysis highlights specific areas in the high pressure gear pump design where flow separation and turbulence may occur, leading to increased noise and reduced operational efficiency. Addressing these velocity perturbations through targeted design modifications can significantly enhance the hydraulic performance of the high pressure gear pump.

Figure 3-34 presents the velocity contours for both outer and inner motors of the high pressure gear pump. Similar to the velocity vector analysis, the outer motor's flow passage exhibits a gradual pressure reduction at the oil inlet. In the region contacting the triangular oil passage, simultaneous changes in flow area and direction cause local oil velocity perturbations. This results in partial conversion of pressure energy to heat energy, leading to pressure losses within the high pressure gear pump system.

The remaining portions of the outer motor's flow passage show relatively uniform velocity changes. In contrast, the inner motor's flow passage in the high pressure gear pump exhibits more uniform velocity distribution overall. The primary perturbation occurs at the contact area between the rectangular oil passage and the triangular oil passage, where changes in flow area and direction create localized velocity variations.

These velocity contour observations are essential for optimizing the high pressure gear pump design, as they identify specific regions where energy losses occur. By modifying these critical areas to ensure more gradual transitions in flow direction and area, we can minimize velocity perturbations and improve the overall efficiency of the high pressure gear pump.

Figure 3-35 presents the simulation results of the optimized outer motor flow passage in the high pressure gear pump. The optimization focused on two key modifications: smoothing the contact regions between the motor's oil inlet and the triangular flow passage, and increasing the flow area in the corresponding regions. Additionally, the contact area between the rectangular flow passage at the oil outlet and the triangular flow passage was smoothed to reduce flow perturbations.

The optimized design of the high pressure gear pump resulted in significant reductions in pressure and velocity perturbations within the flow passage. The pressure changes, velocity vector variations, and overall velocity changes became much more gradual throughout the passage. These improvements directly contribute to reduced pressure energy loss within the high pressure gear pump system, enhancing both efficiency and performance.

The optimization of the outer motor flow passage demonstrates how targeted design modifications can address specific flow issues identified through simulation analysis. By focusing on reducing abrupt changes in flow direction and area, the revised design minimizes turbulence and energy loss in the high pressure gear pump, leading to more efficient operation.

Figure 3-36 shows the simulation analysis results for the optimized inner motor flow passage in the high pressure gear pump. The optimization strategy involved smoothing the contact regions between the inner motor's oil inlet and the triangular flow passage, as well as refining the contact area between the rectangular flow passage at the oil outlet and the triangular flow passage. These modifications were designed to address the specific flow perturbations identified in the original design analysis.

The optimization of the inner motor flow passage in the high pressure gear pump resulted in significant reductions in pressure fluctuations, velocity vector variations, and overall velocity perturbations. These improvements translate directly to reduced pressure energy loss within the system, enhancing the efficiency of the high pressure gear pump. The smoother transitions between different passage sections promote more laminar flow characteristics, minimizing turbulence and associated energy losses.

Comparing the optimized results for both inner and outer motors in the high pressure gear pump reveals that the targeted smoothing modifications effectively address the primary flow issues in both designs. The consistent approach to optimization ensures balanced performance across all components of the high pressure gear pump system, leading to improved overall efficiency and reliability.