The Effect of the Fluid Film Variable Viscosity on the Hydrostatic Thrust Spherical Bearing Performance in the Presence of Centripetal Inertia and Surface Roughness
Ahmad Waguih Yacout Elescandarany
Issue:
Volume 6, Issue 1, February 2018
Pages:
1-12
Received:
31 July 2017
Accepted:
7 August 2017
Published:
7 March 2018
Abstract: In response to the importance of the industry great need to the hydrostatic thrust spherical bearing, this study is performed. The stochastic modified Reynolds equation (developed by the author in his previous papers) applied to this type of bearings has become more developed to deal with the bearing static performance under the effect of the fluid film viscosity variation. The study showed the effect of the viscosity variation on the pressure, the load, the flow rate, the frictional torque, the friction factor, the power factor, the stiffness factor and the central pressure ratio as well as the effect of the speed parameter and the eccentricity on the temperature rise. The partial differential equation of the temperature gradient is derived from the fluid governing equations, integrated and applied to this type of bearings to calculate and predict the temperature distribution along the fluid film. The application of this temperature equation proved the excellence of the aforementioned optimum design of this bearing in our previous papers where the temperature of the outlet flow was less than 14 degrees centigrade over its inlet temperature.
Abstract: In response to the importance of the industry great need to the hydrostatic thrust spherical bearing, this study is performed. The stochastic modified Reynolds equation (developed by the author in his previous papers) applied to this type of bearings has become more developed to deal with the bearing static performance under the effect of the fluid...
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Reproducing Failure Mode and Life Prediction of Expansion Joint Using Field Data
Jung Soo Oh,
Sueng Hyun Cho,
Sung Jae Won,
Dae Kyung Kang,
Bong Soo Lee,
Joong Sik Heo
Issue:
Volume 6, Issue 1, February 2018
Pages:
13-17
Received:
26 April 2018
Published:
27 April 2018
Abstract: In this study, among plant equipment, valve and piping fitting which is vulnerable to waterhammer was selected for diagnosis. Impulsive vibration by waterhammer was measured and applied to HIL simulator as operation data using HILS method for reproducing failure mode and life prediction of them. For effective measuring vibration, accelerometer was adapted for in the poor surroundings. Measurement results shows max. peak-to-peak vibration displacement was 21.40 mm caused by waterhammer on the valve etc., which could affect structure stability of plant equipment. After that, using the acquired data, the vibration durability of the expansion joint was tested. Meanwhile, in the case of vibration durability, internal pressure in the expansion joint was proposed as main stress factor of durability life, life prediction model was induced by curve fitting along with the datum at each pressure and verified. Thus, a further study will develop mixed life prediction model which will contain another stress factor such as temperature.
Abstract: In this study, among plant equipment, valve and piping fitting which is vulnerable to waterhammer was selected for diagnosis. Impulsive vibration by waterhammer was measured and applied to HIL simulator as operation data using HILS method for reproducing failure mode and life prediction of them. For effective measuring vibration, accelerometer was ...
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