Theoretical study on performance of mechanical seals with double parabolic rotating and stationary rings
For the problems of short range and easy tail shaft leakage of autonomous underwater unmanned vehicle(AUV),with the mechanical seal used in the tail shaft drive system of AUV as the research object,a two-dimensional axisymmetric mathematical model was established for a hydrostatic mechanical seal with double parabola faces(DPHS-MS),and the model was experimentally validated;Considering the effects of variation of the sealed fluid viscosity with temperature and pressure,finite difference method was used to numerically analyze and calculate the coupled mathematical model composed of the Reynolds equation,energy equation and other equations;Sealing performance parameters were compared among DPHS-MS,a hydrostatic mechanical seal with single parabola face(PHS-MS),and a hydrostatic mechanical seal within convergent face(CHS-MS)at same geometry and environmental parameters.The results show that the leakage of DPHS-MS is smaller than that of PHS-MS and CHS-MS,and the range and safety reliability of AUV are improved,the range can be increased by more than 1 km under the same working conditions;The influence rules of geometric parameters on the performance of DPHS-MS were obtained,and the geometric parameter design values of DPHS-MS were optimized.The research results can provide theoretical design basis for improving the mechanical sealing effect of AUV tail shaft.