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Full-Text Articles in Mechanical Engineering

Fluid-Wall Interactions In Pseudopotential Lattice Boltzmann Models, Cheng Peng, Luis F. Ayala, Orlando M. Ayala Jan 2021

Fluid-Wall Interactions In Pseudopotential Lattice Boltzmann Models, Cheng Peng, Luis F. Ayala, Orlando M. Ayala

Engineering Technology Faculty Publications

Designing proper fluid-wall interaction forces to achieve proper wetting conditions is an important area of interest in pseudopotential lattice Boltzmann models. In this paper, we propose a modified fluid-wall interaction force that applies for pseudopotential models of both single-component fluids and partially miscible multicomponent fluids, such as hydrocarbon mixtures. A reliable correlation that predicts the resulting liquid contact angle on a flat solid surface is also proposed. This correlation works well over a wide variety of pseudopotential lattice Boltzmann models and thermodynamic conditions.


Reliability Estimation Of Rotary Lip Seal In Aircraft Utility System Based On Time-Varying Dependence Degradation Model And Its Experimental Validation, Chao Zhang, Rentong Chen, Guanghan Bai, Shaoping Wang, Mileta M. Tomovic Jan 2020

Reliability Estimation Of Rotary Lip Seal In Aircraft Utility System Based On Time-Varying Dependence Degradation Model And Its Experimental Validation, Chao Zhang, Rentong Chen, Guanghan Bai, Shaoping Wang, Mileta M. Tomovic

Engineering Technology Faculty Publications

With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based …


Bayesian Model Averaging Based Storage Lifetime Assessment Method For Rubber Sealing Rings, Di Liu, Shaoping Wang, Chao Zhang, Mileta M. Tomovic Jan 2019

Bayesian Model Averaging Based Storage Lifetime Assessment Method For Rubber Sealing Rings, Di Liu, Shaoping Wang, Chao Zhang, Mileta M. Tomovic

Engineering Technology Faculty Publications

Rubber sealing ring is one of the most widely used seals. It is always stored for a period of time before put into use, especially in aeronautic and aerospace applications. It is necessary to evaluate the storage lifetime of rubber sealing rings. However, due to the long storage lifetime of rubber sealing rings, two issues need to be handled, including model uncertainty and lack of storage lifetime data. A Bayesian model averaging based storage lifetime assessment method for rubber sealing rings is proposed in this article. The Gamma distribution model and Weibull distribution model are selected as the candidate models …


Mechanical Wear Debris Feature, Detection, And Diagnosis: A Review, Wei Hong, Wenjian Cai, Shaoping Wang, Mileta M. Tomovic Jan 2018

Mechanical Wear Debris Feature, Detection, And Diagnosis: A Review, Wei Hong, Wenjian Cai, Shaoping Wang, Mileta M. Tomovic

Engineering Technology Faculty Publications

Mechanical debris is an important product of friction wear, which is also a crucial approach to know the running status of a machine. Many studies have been conducted on mechanical debris in related fields such as tribology, instrument, and diagnosis. This paper presents a comprehensive review of these studies, which summarizes wear mechanisms (e.g., abrasive wear, fatigue wear, and adhesive wear) and debris features (e.g., concentration (number), size, morphology, and composition), analyzes detection methods principles (e.g., offline: spectrograph and ferrograph, and online: optical method, inductive method, resistive-capacitive method, and acoustic method), reviews developments of online inductive methods, and investigates the …


Erosion Degradation Characteristics Of A Linear Electro-Hydrostatic Actuator Under A High-Frequency Turbulent Flow Field, Yuan Li, Shaoping Wang, Mileta M. Tomovic, Chao Zhang Jan 2018

Erosion Degradation Characteristics Of A Linear Electro-Hydrostatic Actuator Under A High-Frequency Turbulent Flow Field, Yuan Li, Shaoping Wang, Mileta M. Tomovic, Chao Zhang

Engineering Technology Faculty Publications

The paper proposes a performance degradation analysis model based on dynamic erosion wear for a novel Linear Electro-Hydrostatic Actuator (LEHA). Rather than the traditional statistical methods based on degradation data, the method proposed in this paper firstly analyzes the dominant progressive failure mode of the LEHA based on the working principle and working conditions of the LEHA. The Computational Fluid Dynamics (CFD) method, combining the turbulent theory and the micro erosion principle, is used to establish an erosion model of the rectification mechanism. The erosion rates for different port openings, under a time-varying flow field, are obtained. The piecewise linearization …