Advances in Mechanical Engineering

Zhou, Xing; Di, Qinfeng; Chen, Feng; Wang, Wenchang; Chen, Gong

doi: 10.1177/16878132231168283pmid: N/A

Wear has serious influence on the strength and tightness of tubing joint. In this paper, a new joint wear establishment method, “numerical cutting method,” was proposed and the stress distribution characteristics of sealing surface were analyzed. The three-dimensional modeling of a worn tubing joint under complex loads was successfully established and the finite element method was used to calculate the stress distribution on sealing surface. The influence of internal wear on the stress distribution of the sealing surface was analyzed and the failure mechanism of a worn tubing joint was revealed. The results showed that the contact stress of the worn part of the sealing surface decreases with increased wear depth of internal wear. When the internal wear depth reaches 3.0 mm, the maximum contact stress in the worn area decreases by 35.5% than that of the unworn joint along the axial direction and by 27.3% along the circumferential direction of sealing surface. While when the external wear reaches 3.0 mm, the stress distribution of the sealing surface is similar to that of the unworn joint. These mean that more attention should be paid to the prevention of internal wear during operation because an internal wear has more effect on the stress characteristics of the sealing surface than external wear. The sealing belt is located in the middle of the sealing surface, and the width of the sealing belt at different wear depths is roughly the same for two wear forms. This is beneficial to ensure the seal integrity of tubing joint.

Li, Yang; Yu, Maolin; Bai, Yinming; Hou, Zhaoyang; Zhang, Huijie; Wu, Wenwu

doi: 10.1177/16878132231167675pmid: N/A

High-speed spindle systems could generate sufficient heat when they are operating and would cause thermal deformation that influences spindle accuracy. Heat dissipation is a common and effective way to remove the generated heat. In this paper, heat conductive paths were created on the bearing seat and the spindle housing along the radial direction. Along these paths, the heat was transferred directly from heat sources inside the spindle system to outside and the heat dissipation was enhanced. To limit the heat transferred along the axial direction, the inner wall of the path was coated with a thermal insulation material. Based on an annular plate model, the influences of the affecting parameters of paths on the heat transfer performance were studied. The temperature distributions of the models with and without heat conductive paths were numerically and experimentally investigated. It was found that after using heat conductive paths, the heat dissipation enhanced significantly. Moreover, it is found that as the number and diameter of paths increases, the temperature of internal parts decreases and the gap between the highest and the lowest temperature is narrowed.

Takemura, Reiya; Aoki, Nobuaki; Ishigami, Genya

doi: 10.1177/16878132231169688pmid: N/A

This paper presents an energy and perception aware framework for path planning and navigation of unmanned aerial vehicles (UAVs) in GNSS-denied and spatiotemporal wind environments. The proposed framework mainly consists of the global and local path planning methods that respectively consider the energy consumption of an UAV and perception quality of a light detection and ranging (LiDAR) sensor mounted on the UAV. The energy consumption is estimated based on the aerodynamic model that calculates drag and lift forces on the UAV. The global planner then uses the total energy consumption in the spatiotemporal wind as the cost function to find an energy-efficient path as a set of waypoints. The local path planning navigates the UAV between the waypoints with maintaining the perception quality. The perception quality is quantified based on how well the LiDAR sensor scans feature points around the UAV that highly correlates with the navigation accuracy. Numerical simulation study for each of the global and local path planners validates their usefulness. Further, the overall framework is entirely verified in a long-range flight scenario of the photorealistic environments developed in the Gazebo simulation.

Ebaid, Munzer SY; Shahin, Zin Alabdin AE; Alshawabkeh, Mohammad MD

doi: 10.1177/16878132231165964pmid: N/A

The proposed work aims to generate electricity by utilising the air flowing around the vehicle through the micro wind turbines (MWTs). In this case, the electricity produced can be used to charge up the battery or power up additional vehicle accessories, which increases the efficiency or/and range of the vehicle. Three driving cycles have been conducted to examine the model’s performance in moderate, highly dynamic and highway driving scenarios. The analytical works resulted in an 8.38%, 4.6% and 1.01% efficiency increase for the case of the Highway driving cycle (FTP), the new European driving cycle (NEDC) and the standardisation random test aggressive driving cycle (RTS), respectively when adding the micro wind turbines model. In terms of range analysis, 16, 11 and 2 km of the range were added to the full battery charge range of the vehicle when the vehicle was simulated for the case FTP, NEDC and RTS driving cycles scenarios, respectively. The results conclude that the value of micro wind turbines is shimming with highway driving scenarios where the effect of regenerative braking is absent and the drag force acting on the vehicle is at its highest rate.

Alhashash, Abeer; Saleh, Habibis

doi: 10.1177/16878132231167947pmid: N/A

Transient free convection in a composite enclosure having a cold flexible plate and a hot rigid plate is simulated numerically. It is assumed that the flexible plate is hyper-elastic. A porous layer with various sizes and permeabilities is attached to the rigid plate. The enclosure is filled with water. Fluid flow in the fluid domain was governed by the Navier–Stokes equations, and the flow within a saturated porous layer was governed by the Brinkman-Forchheimer extended Darcy model. The unsteady continuity, momentum, and energy equations are solved using the Arbitrary-Lagrangian-Eulerian (ALE) approach based on the fluid-structure interaction (FSI). It is found that the development of convective flow goes through initial, transitional, and stationary states. Each state interval is shifted by varying the Darcy number and Rayleigh number. In the transitional state, the deformation of the flexible parts reaches its maximum bending. The profile of the flexible plate at steady state is in a sinusoidal shape for the non-Darcy regime, while it is in an asymmetric parabolic shape for the Darcy regime. The steady state is reached for Da→∞, Da=10−3, and Da=10−5 before τ=0.061,0.065,0.091.

Chen, Runlin; Liu, Jiaxin; Tang, Jie; Han, Qin; Zhang, Yanchao; Cui, Yahui

doi: 10.1177/16878132231167670pmid: N/A

Because of the radial clearance, the radial stiffness of rolling bearing will show obvious time-varying characteristics, which may cause a certain vibration. The small defects on the raceway of the rolling bearing maybe caused by the vibration under the poor lubrication conditions. A dynamic model of rolling bearing rotor system considering the radial clearance and outer raceway defect is established in this paper. The time-varying stiffness of rolling bearing is fitted by 8-order Fourier series and substituted into the dynamic model. The vibration response of rotor system is obtained to analyze the fault characteristic frequency of rolling bearing. The vibration test of rolling bearing rotor system is carried out, and the fault characteristic frequency of the test bearing is identified by analyzing the frequency spectrum of the obtained vibration signal. The test results are in good agreement with the theoretical values, which verifies the correctness of the dynamic model.

Saveljev, Vladimir; Son, Jung-Young; Lee, Hyoung; Heo, Gwanghee

doi: 10.1177/16878132221143885pmid: N/A

We measured vertical and horizontal displacements of distant objects based on the moiré effect. The grid attached to the object was photographed and recorded on video camera. The video was processed later in the lab. The method is self-calibrated and does not need special equipment in the field (except for a regular videographer’s apparatus). The objectives of this study were to create a method for non-contact moiré measurement based on camera images and to find a way to deal with anomalous vibrations of structures. The experimental measurements of the fundamental frequency are in accordance with the theory of square beams. Tests with broken models were also conducted. The influence of two opposite factors on the fundamental frequency in the beams with cracks was estimated. In determining the pre-failure condition, the decay rate seems to be a more promising indicator than the fundamental frequency; however, this was only observed when a crack was near the fixed edge. The results and findings can be applied in measuring displacement in various objects; in public safety, and particularly, in distinguishing between normal and abnormal vibration in bridges.

Kuo, Chan-Sheng; Kang, Yowei; Yang, Hung-Lin

doi: 10.1177/16878132231165973pmid: N/A

With the rapid developments in cloud technology, the cloud Enterprise Resource Planning (ERP) system is indispensable when investigating the adoption and implementation of manufacturing systems among industries. The cloud ERP system can support manufacturing systems through various cloud services. The study was based on the well-known Information Systems Success Model (ISSM) to explore the predictive power of these theory-based variables. Our research provides an integrated managerial model to predict the continuance intention of adopting the cloud ERP system to enable effective manufacturing. The paper employed Structural Equation Model (SEM) to verify and confirm the hypotheses from an online survey in Taiwan. The empirical results have confirmed that (1) self-efficacy and convenience positively predict perceived ease of use; (2) information quality, system quality, service quality, perceived price, and perceived ease of use positively predict satisfaction; perceived security has no significant effect on satisfaction; (3) perceived ease of use, perceived security and satisfaction positively predict continuance intention. This study’s analysis results thus provide a suitable integrated framework to predict continuance intention. Finally, our research provides practical and managerial recommendations for manufacturing industries of adopting the cloud ERP system.

Yi, Shuxiang; Wang, Xiaojing; Chen, Sheng; Yuan, Weimin

doi: 10.1177/16878132231170785pmid: N/A

Some degree of inertia effect on the bearing film is inevitable for high density supercritical carbon dioxide (S-CO2) working as a lubricant in high speed rotor operating conditions. This paper aims to reveal the influence of inertia effect on static and dynamic performances of the S-CO2 tilting pad bearings. Numerical results demonstrate that inertia effect on the lubricating film of the top pad is more pronounced. The peak pressure of all pads is increased at a high reduced Reynolds number compared with the inertialess condition, while the influence of inertia effect on the dynamic coefficient is weak. The theoretical model including inertia effect presented in this study can more accurately evaluate the performance of high speed S-CO2 tilting pad bearings.

Jiang, Minzheng; Chang, Siyuan; Dong, Kangxing

doi: 10.1177/16878132231162186pmid: N/A

Compared with the rod-pumping oil production system of the conventional pumping unit, the structure of the down-hole oil-water separation system from the rod pump is more complicated, and the down-hole working conditions are worse. Existing technology no longer meets the needs of its downhole condition diagnosis. It seriously affected the production output and economic benefits of the oil field. Because of this, a fault pre-diagnosis method for the downhole oil-water separation system from the rod pump was proposed. Through the theoretical calculation of oil well production and pump efficiency. After field investigation and collection of many suspension point indicators diagrammed for comparison and analysis, the injection pump’s failure probability was 90% above. At this time, the extraction pumps work normally. Therefore, a reverse calculation method is proposed: establish and solve the static/dynamic load model of the production pump, and obtain the load-displacement function of the production pump. The load-displacement function of the suspension point derived from the suspension point indicator diagram is subtracted from the calculated load-displacement function of the production pump to obtain the load-displacement function of the injection pump so that the working condition diagnosis can be performed according to the injection pump work diagram. In the application of 18 wells within the field, the judgment result of injection pump failure and the result of pump inspection coincided with 91.3%, which verified the correctness of the calculation model. This method provides necessary theoretical guidance for the field application and working condition diagnosis of rod pump downhole oil-water separation system and is of great significance for improving the comprehensive benefit of oilfield production.