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Browsing by Author "Li, Yafeng"
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Item Design, Modeling, and Fabrication of a Ventilator Prototype - A Successful Student Project Story(ASME, 2021-11) Yeong, Haoyee; Iloeje, Francis; Kindomba, Eli; Folorunso, Sunday; Li, Yafeng; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and TechnologyAbstract In this work, we use a group project approach for a group of undergraduate students to design and develop a mechanical ventilator, in response to the COVID-19 pandemic. A student group project composed of a team of undergraduate students has successfully designed and fabricated a mechanical bag valve mask (BVM) ventilator prototype. It is lightweight with a single controller is driven, capable of volume adjustment, inexpensive, open-source, and designed for ease of fabrication, installation, and operation by the average user. The ventilator prototype also consists of 3D printed components and stored bought hardware. A finite element model was developed to analyze the deformation of the bag valve mask. Finally, the ventilator system is fully tested functioning properly.Item Finite Element Modeling of Coating Thickness Using Heat Transfer Method(Elsevier, 2021-01) Li, Yafeng; Dhulipalla, Anvesh; Zhang, Jian; Park, Hye-Yeong; Jung, Yeon-Gil; Koo, Dan Daehyun; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and TechnologyA new heat transfer based finite element model is proposed to simulate coating thickness in the electron-beam physical vapor deposition (EB-PVD) process. The major advantage of the proposed model is that it is much computationally efficient than the traditional ray-tracing based model by about two orders of magnitude. This is because the Gaussian distribution heating source has the same profile as the cosine relation used in the ray-tracing method. Firstly, the model simulates the temperature profile of a metal substrate heated by a heating source with a Gaussian distribution. Then using a calibrated conversion process, the temperature profile is converted to corresponding coating thickness. The model is successfully demonstrated by three validation cases, including a stationary disk, a stationary cylinder, and a rotary three-pin component. The predicted coating thicknesses in the validation cases are in good agreement with either the ray-tracing based analytical solution or experimental data. After its validation, the model is applied to a rotary turbine blade to predict its coating thickness distribution. In summary, the model is capable to simulate coating thickness in complex shaped parts.Item Modeling of Temperature Swing Effect in Silica Reinforced Porous Anodized Aluminum Based Thermal Barrier Coating(SAE International, 2021) Gulhane, Abhilash; Zhang, Jian; Yang, Xuehui; Lu, Zhe; Park, Hye-Yeong; Jung, Yeon-Gil; Li, Yafeng; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and TechnologyThis paper presents a finite element (FE) based model to simulate the temperature swing phenomenon of Silica Reinforced Porous Anodized Aluminum (SiRPA) thermal barrier coatings (TBCs). A realistic 3D SiRPA coating microstructure is constructed, based on the morphology of an experimentally grown coating structure, and the known relationship of geometry and anodization parameters. The coatings’ thermophysical properties are first computed using the FE model. The predicted thermal conductivity, thermal diffusivity, and bulk density are compared well with the experimental values. Also, transient thermal analysis is conducted to model the temperature swing effect of the coating by comparing the temperature fluctuation of SiRPA coating with conventional Yttria Stabilized Zirconia (YSZ) based TBCs. With the predicted thermophysical properties, the model is capable to predict the “temperature swing” effect of SiRPA by a transient thermal analysis. Temperature fluctuation of SiRPA is found greater compared to YSZ coating, suggesting its applicability in internal combustion engines. The porosity-dependent thermal conductivity of SiRPA coating is numerically derived. The thermal conductivity decreases linearly with increasing total porosity. The modeling data illustrate that the SiRPA coating shows a higher fluctuation compared to YSZ based TBCs, suggesting its applicability in internal combustion engines.Item A Project Based Learning Study Through Student Design of a Low-cost, Open Source, Easy-to-use, and Easy-to-build Ventilator(2021) Kindomba, Eli; Iloeje, Francis; Yeong, Haoyee; Folorunso, Sunday; Zhengzhao, Ji; Li, Yafeng; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and TechnologyThis work presents a project based learning (PBL) study, through student design and fabrication of a low-cost, open source, easy-to-build, and easy-to-use bag valve mask (BVM) ventilator, to potentially serve COVID-19 patients during the incubation period. A new learning outcomes framework, i.e., Profiles of Learning for Undergraduate Success, was adopted as the pedagogical model, with a focus on problem solver and innovator. Using the reciprocating motion system, the ventilator is capable to provide an air supply with adjustable breath frequencies. 3D printing is used to fabricate customized components. In parallel to the mechanical assembly of the ventilator, a CAD model was developed to understand the motion mechanisms in the ventilator, which can further help optimize the system. The design files are available at GitHub for open access. The project is to serve as a backup to handle any surge of patients who may need breathing assistance in hospitals across the nation. The feedback from the participating students is very positive. The success of this PBL based project using the profiles of learning for undergraduate success shows its promise and it can be extended to other student learning experiences.Item Three-dimensional analytical models for predicting coating thickness on non-axial symmetrical workpieces in electron beam physical vapor deposition(Elsevier, 2022-08) Li, Yafeng; Ji, Zhengzhao; Dhulipalla, Anvesh; Zhang, Jian; Yang, Xuehui; Dube, Tejesh; Kim, Bong-Gu; Jung, Yeon-Gil; Koo, Dan Daehyun; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and TechnologyIn this work, three-dimensional (3D) analytical models for non-axial symmetric workpieces, including ellipsoid and cylinder, are derived to predict the coating thickness distributions in the EB-PVD process. Additionally, 3D analytical models for axial symmetric workpieces, including disk and sphere are presented, which will be used for deriving the non-axial symmetric workpiece solutions. The models are based on extending the two-dimensional (2D) models of a disk workpiece by Schiller et al. (1982) and a circular arc on a cylinder by Fuke et al. (2005). The 3D models for disk and sphere workpieces are also presented which are used to derive the non-axial symmetric models. The results show that the 3D analytical models are consistent with the 2D models, and also in excellent agreement with our finite element (FE) model predictions and experimental data in the literature.