Effects of wear ring clearance on hydraulically generated vibration and noise of a centrifugal pump volute

The wear ring clearance of centrifugal pumps is of significant importance for numbers of effects. In the paper, these effects including the performance, pressure pulsations, hydraulically generated vibration and noise level are investigated. For the purpose, a numerical method combined the FEM and BEM analysis was developed to predict the vibration and sound radiation of the volute. The numerical simulations with and without leakage flow paths being considered were compared. Additionally, the simulation results were validated by the vibration acceleration of the monitoring points on the volute. On this basis, the effects of wear ring clearance were analyzed. The results show that the quality of vibration simulation for centrifugal pumps can be improved by involving the leakage flow paths in simulations. Based on an overall consideration of the performance, pressure pulsations, vibration and noise, the optimum wear ring clearance is supposed to be 0.6 mm for the centrifugal pump (nqSI= 26.7). The results can be used to guide the optimum design of the pump wear ring clearance

Challenges in Attaining Sustainable Development Goals in Port Klang: Port Management Perspective

Sustainable development goals revolve around three broad elements: cost reduction, productivity enhancement and environmental protection. Seaport industry is inextricably linked to enormous competitions; requiring unceasing improvements to be able to achieve competitive advantages by addressing the relevant sustainable development goals. Dynamic capabilities theory is incorporated in this study to substantiate the relationship between sustainable development goals and sustainable competitive advantages. In addition, dynamic capabilities theory provides a guideline for port management in ascertaining efforts needed to stay relevant in the ever demanding seaport business. Nonetheless, in the process of attaining sustainable development goals, challenges are faced by port management. This study incorporates a qualitative approach, focusing in port Klang particularly on Northport and Westport due to the high volume of cargo handled and being national economic barometers. Interviews were conducted whereby the respondents were managerial personnel in their respective departments. The findings indicate that the challenges in attaining sustainable development goals comprise of technological constraints, financing issues, human capital barriers and supplier associated problems. Addressing these stumbling blocks proves advantageous for port Klang whereby the attainable sustainable development goals is a catapulting factor for ports to achieve sustained competitive advantages in the future

Collaborative simulation method with spatiotemporal synchronization process control

When designing a complex mechatronics system, such as high speed trains, it is relatively difficult to effectively simulate the entire system’s dynamic behaviors because it involves multi-disciplinary subsystems. Currently, a most practical approach for multi-disciplinary simulation is interface based coupling simulation method, but it faces a twofold challenge: spatial and time unsynchronizations among multi-directional coupling simulation of subsystems. A new collaborative simulation method with spatiotemporal synchronization process control is proposed for coupling simulating a given complex mechatronics system across multiple subsystems on different platforms. The method consists of 1) a coupler-based coupling mechanisms to define the interfacing and interaction mechanisms among subsystems, and 2) a simulation process control algorithm to realize the coupling simulation in a spatiotemporal synchronized manner. The test results from a case study show that the proposed method 1) can certainly be used to simulate the sub-systems interactions under different simulation conditions in an engineering system, and 2) effectively supports multi-directional coupling simulation among multi-disciplinary subsystems. This method has been successfully applied in China high speed train design and development processes, demonstrating that it can be applied in a wide range of engineering systems design and simulation with improved efficiency and effectiveness

Effects of wear ring clearance on hydraulically generated vibration and noise of a centrifugal pump volute

The wear ring clearance of centrifugal pumps is of significant importance for numbers of effects. In the paper, these effects including the performance, pressure pulsations, hydraulically generated vibration and noise level are investigated. For the purpose, a numerical method combined the FEM and BEM analysis was developed to predict the vibration and sound radiation of the volute. The numerical simulations with and without leakage flow paths being considered were compared. Additionally, the simulation results were validated by the vibration acceleration of the monitoring points on the volute. On this basis, the effects of wear ring clearance were analyzed. The results show that the quality of vibration simulation for centrifugal pumps can be improved by involving the leakage flow paths in simulations. Based on an overall consideration of the performance, pressure pulsations, vibration and noise, the optimum wear ring clearance is supposed to be 0.6 mm for the centrifugal pump (nqSI= 26.7). The results can be used to guide the optimum design of the pump wear ring clearance

Federated Learning in Intelligent Transportation Systems: Recent Applications and Open Problems

Intelligent transportation systems (ITSs) have been fueled by the rapid development of communication technologies, sensor technologies, and the Internet of Things (IoT). Nonetheless, due to the dynamic characteristics of the vehicle networks, it is rather challenging to make timely and accurate decisions of vehicle behaviors. Moreover, in the presence of mobile wireless communications, the privacy and security of vehicle information are at constant risk. In this context, a new paradigm is urgently needed for various applications in dynamic vehicle environments. As a distributed machine learning technology, federated learning (FL) has received extensive attention due to its outstanding privacy protection properties and easy scalability. We conduct a comprehensive survey of the latest developments in FL for ITS. Specifically, we initially research the prevalent challenges in ITS and elucidate the motivations for applying FL from various perspectives. Subsequently, we review existing deployments of FL in ITS across various scenarios, and discuss specific potential issues in object recognition, traffic management, and service providing scenarios. Furthermore, we conduct a further analysis of the new challenges introduced by FL deployment and the inherent limitations that FL alone cannot fully address, including uneven data distribution, limited storage and computing power, and potential privacy and security concerns. We then examine the existing collaborative technologies that can help mitigate these challenges. Lastly, we discuss the open challenges that remain to be addressed in applying FL in ITS and propose several future research directions