109 research outputs found

    Virtue integrated platform : holistic support for distributed ship hydrodynamic design

    Get PDF
    Ship hydrodynamic design today is often still done in a sequential approach. Tools used for the different aspects of CFD (Computational Fluid Dynamics) simulation (e.g. wave resistance, cavitation, seakeeping, and manoeuvring), and even for the different levels of detail within a single aspect, are often poorly integrated. VIRTUE (the VIRtual Tank Utility in Europe) project has the objective to develop a platform that will enable various distributed CFD and design applications to be integrated so that they may operate in a unified and holistic manner. This paper presents an overview of the VIRTUE Integrated Platform (VIP), e.g. research background, objectives, current work, user requirements, system architecture, its implementation, evaluation, and current development and future work

    A multi-fault diagnosis method for piston pump in construction machinery based on information fusion and PSO-SVM

    Get PDF
    Piston pumps are key components in construction machinery, the failure of which may cause long delay of the construction work and even lead to serious accident. Because construction machines are exposed to poor working conditions, multiple faults of piston pumps are most likely to occur simultaneously. When multiple faults occur together, it is difficult to detect. A multi-fault diagnosis method for piston pump based on information fusion and PSO-SVM is proposed in this thesis. Information fusion is used as fault feature extraction and PSO-SVM is applied as the fault mode classifier. According to the method, vibration signal and pressure signal of piston pump in normal state, single fault state and multi-fault state are collected at first. Then the empirical mode decomposition (EMD) is used to decompose vibration signals into different frequency band and energy features are extracted. These energy features extracted from vibration signals and time-domain features extracted from pressure signal are information fused at the feature layer and constitute the eigenvectors. Finally, these eigenvectors are put into support vector machine (SVM) and the working conditions of piston pump were classified. Particle swarm optimization (PSO) is applied to optimize two parameters of SVM. The experimental results show that the recognition accuracy of the normal state, three single failure modes and multi-fault modes are 98.3 %, 97.6 % and 94 % respectively. These recognition accuracies are higher than which using vibration signal or pressure signal alone. So, the proposed method can not only identify the single fault, but also effectively identify the multi-fault of piston pump

    A virtual environment to support the distributed design of large made-to-order products

    Get PDF
    An overview of a virtual design environment (virtual platform) developed as part of the European Commission funded VRShips-ROPAX (VRS) project is presented. The main objectives for the development of the virtual platform are described, followed by the discussion of the techniques chosen to address the objectives, and finally a description of a use-case for the platform. Whilst the focus of the VRS virtual platform was to facilitate the design of ROPAX (roll-on passengers and cargo) vessels, the components within the platform are entirely generic and may be applied to the distributed design of any type of vessel, or other complex made-to-order products

    VIRTUE : integrating CFD ship design

    Get PDF
    Novel ship concepts, increasing size and speed, and strong competition in the global maritime market require that a ship's hydrodynamic performance be studied at the highest level of sophistication. All hydrodynamic aspects need to be considered so as to optimize trade-offs between resistance, propulsion (and cavitation), seakeeping or manoeuvring. VIRTUE takes a holistic approach to hydrodynamic design and focuses on integrating advanced CFD tools in a software platform that can control and launch multi-objective hydrodynamic design projects. In this paper current practice, future requirements and a potential software integration platform are presented. The necessity of parametric modelling as a means of effectively generating and efficiently varying geometry, and the added-value of advanced visualization, is discussed. An illustrating example is given as a test case, a container carrier investigation, and the requirements and a proposed architecture for the platform are outlined

    MiliPoint: A Point Cloud Dataset for mmWave Radar

    Full text link
    Millimetre-wave (mmWave) radar has emerged as an attractive and cost-effective alternative for human activity sensing compared to traditional camera-based systems. mmWave radars are also non-intrusive, providing better protection for user privacy. However, as a Radio Frequency (RF) based technology, mmWave radars rely on capturing reflected signals from objects, making them more prone to noise compared to cameras. This raises an intriguing question for the deep learning community: Can we develop more effective point set-based deep learning methods for such attractive sensors? To answer this question, our work, termed MiliPoint, delves into this idea by providing a large-scale, open dataset for the community to explore how mmWave radars can be utilised for human activity recognition. Moreover, MiliPoint stands out as it is larger in size than existing datasets, has more diverse human actions represented, and encompasses all three key tasks in human activity recognition. We have also established a range of point-based deep neural networks such as DGCNN, PointNet++ and PointTransformer, on MiliPoint, which can serve to set the ground baseline for further development

    Stream Simulation Design of Conn Creek Culvert

    Get PDF
    Abstract Conventional culvert designs based on hydraulic capacity often result in high velocities or inadequate water levels that are not conducive for fish migration. For fish-bearing stream crossings, alternative designs need to be developed in order to secure timely approval from Fisheries and Oceans Canada (DFO). Stream simulation is one of those alternatives. It was proposed to, and accepted by, DFO for the Conn Creek Culvert replacement in Fort McMurray, an environmentally sensitive site due to the controversy over Alberta oil sand projects. The existing 4.2 m diameter, 82 m long culvert carries four lanes of Highway 63 traffic across Conn Creek, a tributary to the Athabasca River. As part of the $530 million Highway 63:11 upgrading project, the existing culvert required extension. During the review of the proposed alternatives, DFO cited the high flow velocity within the existing culvert as a barrier to fish passage, resulting in the separation of upstream and downstream habitats. Authorization for the works would need to ensure fish passage was restored. Challenges encountered during the design and construction of the replacement culvert included: Traffic accommodation for a busy highway with over 50K Average Annual Daily Traffic (AADT) Tight construction schedule demanding a quick approval from DFO Providing fish passage for weak swimming fish species across a 120 m span Enabling fish passage by reducing flows and providing velocity refuge while also addressing constructability and economics. Reducing flow velocity in a system that had been significantly altered historically (stream length shortened by removal of large meander sections of the natural stream). Shallow limestone bedrock demanding blasting for closed bottom culvert installation Owner's concerns of high construction cost and potential scouring of open bottom culvert This paper presents the background of the project, the existing fisheries, and details of the stream simulation design used to satisfy regulatory and project requirements. It is also the authors' intention to share their experiences and lessons learned in securing a timely approval from DFO on an extremely tight schedule.
    corecore