Influence Analysis of the Rounding Technique of Spiral Groove Root on the Performance of Upstream Pumping Mechanical Seal

In order to improve the performance of the upstream pumping mechanical seal, and considering one specific spiral groove upstream pumping mechanical seal, an improvement project about the groove structure on the seal surface is put forward. The slipping mesh technique was adopted to simulate the internal flow. After simulation, the pressure pulsation at different monitor points are compared and analyzed, and BVF (boundary vortex flow) diagnosis method is used to analyze the results, which is to explore the relationship between groove type and sealing performance. The results shows that the groove root with fillet compared to acute angle can improve the effect of dynamic pressure at the root of groove and increase static pressure in high pressure area. But overlarge round radius will weaken the pumping effect of spiral groove and increase vortex flow. It can also increase flow loss at groove root area, which will reduce of opening force of liquid film and increase the amplitude of pressure pulsation that affect the stability of the sealing performance. Hence, an optimum radius groove length ratio Rr exists, which can acquire the largest sealing performance and good stability, and this can provide reference to improve the upstream pumping mechanical seal performance.