Modeling and simulation of oil leakage in radial lip seals

Yıldız, Meltem
Radial lip seals are used to prevent leakage between machine elements in many industrial applications. During operation, fluid film between seal lip and shaft surface generates a pressure distribution on the lip which is elastically deformed due to hydrodynamic pressure. Surface roughness parameters in terms of moments of height profile distribution (rms roughness, skewness and kurtosis) affect the rate of oil leakage. A computer program is developed for elastohydrodynamic analysis of radial lip seals. Both the fluid mechanics of the lubricating film and the elastic deformation of the lip are taken into consideration to determine the hydrodynamic pressure distribution and the oil flow through the seal lip. The effect of shaft surface roughness on hydrodynamic analysis is taken into account by using average Reynolds equation with flow factors. For non-Gaussian surfaces, the modified flow factors are used to investigate the effects of skewness and kurtosis on the oil leakage. Numerical tests are performed for different skewness, kurtosis and initial seal tightness values. Results show that when a seal is mounted with a high initial tightness, the hydrodynamic pressure developed is not enough to deform the lip to form a fluid film between the shaft and the seal lip. It is observed that for the same rms roughness and skewness, the side flow rate increases as the kurtosis value increases. However, for the same rms roughness and kurtosis values, the side flow rate decreases for all skewness values.


Effect of Turbine Blade Tip Cooling Configuration on Tip Leakage Flow and Heat Transfer
Sakaoglu, Sergen; Kahveci, Harika Senem (ASME International, 2020-02-01)
The pressure difference between suction and pressure sides of a turbine blade leads to tip leakage flow, which adversely affects the first-stage high-pressure (HP) turbine blade tip aerodynamics. In modern gas turbines, HP turbine blade tips are exposed to extreme thermal conditions requiring cooling. If the coolant jet directed into the blade tip gap cannot counter the leakage flow, it will simply add up to the pressure losses due to leakage. Therefore, the compromise between the aerodynamic loss and the g...
Exact solution of rotating FGM shaft problem in the elastoplastic state of stress
Akis, Tolga; Eraslan, Ahmet Nedim (Springer Science and Business Media LLC, 2007-10-01)
Plane strain analytical solutions to estimate purely elastic, partially plastic and fully plastic deformation behavior of rotating functionally graded (FGM) hollow shafts are presented. The modulus of elasticity of the shaft material is assumed to vary nonlinearly in the radial direction. Tresca's yield criterion and its associated flow rule are used to formulate three different plastic regions for an ideal plastic material. By considerina different material compositions as well as a wide range of bore radi...
Investigation of wear behavior of aged and non-aged SiC-reinforced AlSi7Mg2 metal matrix composites in dry sliding conditions
ÇELİK, YAHYA HIŞMAN; Demir, Mehmet Emin; KILIÇKAP, EROL; Kalkanlı, Ali (Springer Science and Business Media LLC, 2020-01-01)
Metal matrix composites (MMCs) with their splendid mechanical properties have been specifically designed for use in fields such as aerospace and aviation. The presence of hard ceramic particles in MMC increases the hardness of the matrix product and decreases its coefficient of friction. Therefore, the wear resistance is improved. Moreover, the mechanical properties of these composite materials can be improved by applying heat treatments. In this study, AlSi7Mg2 MMCs with 15 wt% SiC reinforcement were produ...
Analysis and design for aluminum forging process
Öztürk, Hüseyin; Gökler, Mustafa İlhan; Department of Mechanical Engineering (2008)
Aluminum forging products has been increasingly used in automotive and aerospace industry due to their lightness and strength. In this study, aluminum forging processes of a particular industrial part for the two different alloys (Al 7075 and Al 6061) have been analyzed. The forging part, forging process and the required dies have been designed according to the aluminum forging design parameters. The proposed process has been simulated by using the Finite Volume Method. In the simulations, analysis of the p...
Mixed-mode fracture analysis of orthotropic functionally graded materials
Sarıkaya, Duygu; Dağ, Serkan; Department of Mechanical Engineering (2005)
Functionally graded materials processed by the thermal spray techniques such as electron beam physical vapor deposition and plasma spray forming are known to have an orthotropic structure with reduced mechanical properties. Debonding related failures in these types of material systems occur due to embedded cracks that are perpendicular to the direction of the material property gradation. These cracks are inherently under mixed-mode loading and fracture analysis requires the extraction of the modes I and II ...
Citation Formats
M. Yıldız, “Modeling and simulation of oil leakage in radial lip seals,” M.S. - Master of Science, Middle East Technical University, 2010.