The existing leakage models,which include smooth plane leakage model,rough and waveform surface leakage model,and tapered-face leakage model,can not be applied to describing the active state of contacting mechanical s...The existing leakage models,which include smooth plane leakage model,rough and waveform surface leakage model,and tapered-face leakage model,can not be applied to describing the active state of contacting mechanical seal.In these models,only prime microscopic surface topography and constant leakage rate are taken into consideration.Based on fractal geometry theory,a leakage model was established with consideration of the change of microscopic surface topography and time-correlation of leakage rate.The relationship between leakage rate,the change of microscopic surface topography of seal surface and leaking channel under operation conditions was described quantitatively by fractal parameter with unattached dimension.There existed an optimum fractal parameter during the mechanical seal running,which corresponded to the lowest leakage rate.The research results helped to ascertain the roughness and waviness of seal surface,and to select machining methods of sealing members.According to the leakage model presented in this paper,the leakage rate of contacting mechanical seal can be forecasted,which may be used as reference in the maintenance and operation of mechanical seals.展开更多
Available leakage models of gasket seal are stated in the paper.The sealing test of noncompressed asbestos gaskets and flexible graphite reinforced gaskets are carried out and the parameters of the leakage rate formul...Available leakage models of gasket seal are stated in the paper.The sealing test of noncompressed asbestos gaskets and flexible graphite reinforced gaskets are carried out and the parameters of the leakage rate formula of porous media model are obtained.On the basis of this work it is possible that the seal design procedure prescribed in the codes in effect and mainly based on the strength criterion will be developed into the “tightness design procedure”based on the criterion of the maximal allowable leakage rate.展开更多
文摘The existing leakage models,which include smooth plane leakage model,rough and waveform surface leakage model,and tapered-face leakage model,can not be applied to describing the active state of contacting mechanical seal.In these models,only prime microscopic surface topography and constant leakage rate are taken into consideration.Based on fractal geometry theory,a leakage model was established with consideration of the change of microscopic surface topography and time-correlation of leakage rate.The relationship between leakage rate,the change of microscopic surface topography of seal surface and leaking channel under operation conditions was described quantitatively by fractal parameter with unattached dimension.There existed an optimum fractal parameter during the mechanical seal running,which corresponded to the lowest leakage rate.The research results helped to ascertain the roughness and waviness of seal surface,and to select machining methods of sealing members.According to the leakage model presented in this paper,the leakage rate of contacting mechanical seal can be forecasted,which may be used as reference in the maintenance and operation of mechanical seals.
文摘Available leakage models of gasket seal are stated in the paper.The sealing test of noncompressed asbestos gaskets and flexible graphite reinforced gaskets are carried out and the parameters of the leakage rate formula of porous media model are obtained.On the basis of this work it is possible that the seal design procedure prescribed in the codes in effect and mainly based on the strength criterion will be developed into the “tightness design procedure”based on the criterion of the maximal allowable leakage rate.
