Day 1 Tue, February 22, 2022最新文献

{"title":"VIScous Vorticity Equation (VISVE) Model Applied to oscillatory Turbulent Flow around a Cylinder","authors":"R. You, Akhilesh S. Tiwari, S. Kinnas","doi":"10.5957/tos-2022-008","DOIUrl":"https://doi.org/10.5957/tos-2022-008","url":null,"abstract":"The VIScous Vorticity Equation (VISVE) method has previously been applied to the laminar oscillatory flow around a circular cylinder (Li and Kinnas (2017); Wu and Kinnas (2021a)). In this work, the VISVE method is applied to the oscillatory turbulent flow around a cylinder. To handle the flow within the turbulent regime, the k-w SST turbulence model is employed for calculating the turbulent viscosity. The VISVE and the k-w SST 2-equation turbulence model are both discretized based on the Finite Volume Method (FVM), with Quadratic Upstream Interpolation for Convective Kinematics (QUICK) method dealing with the convective terms, and the Alternating Direction Implicit (ADI) method calculating the unsteady terms. The method is applied to various Reynolds and Keulegan-Carpenter numbers, and the results, including vorticities and velocities are compared with those from a Reynolds-Averaged Navier-Stokes (RANS) solver. The results of turbulent VISVE agree well with those from RANS for KC =2, but deviate from RANS at a higher KC number.","PeriodicalId":108360,"journal":{"name":"Day 1 Tue, February 22, 2022","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134045137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Capsize of Liftboat in Transit","authors":"W. P. Stewart","doi":"10.5957/tos-2022-002","DOIUrl":"https://doi.org/10.5957/tos-2022-002","url":null,"abstract":"The 2021 capsize of the liftboat Seacor Power, with loss of 13 lives, has focused attention on the afloat stability of liftboats in transit. This paper presents a numerical method of simulating the dynamic capsize of liftboats in waves using time domain analysis and a commonly used computer program. Capsize of a similar vessel to the Seacor Power is predicted in 6-ft quartering and beam seas even without wind. Model tests are proposed to help calibrate calculation techniques and define limiting metocean conditions more reliably for safe transit of liftboats.","PeriodicalId":108360,"journal":{"name":"Day 1 Tue, February 22, 2022","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127406966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virtual Telepresence for the Future of ROV Teleoperations: Opportunities and Challenges","authors":"Pengxiang Xia, K. McSweeney, Feng Wen, Zhuoyuan Song, Michael Krieg, Shuai Li, Xiao Yu, Kent J. Crippen, Jonathan E Adams, E. Du","doi":"10.5957/tos-2022-015","DOIUrl":"https://doi.org/10.5957/tos-2022-015","url":null,"abstract":"Underwater robots, including Remote Operating Vehicles (ROV) and Autonomous Underwater Vehicles (AUV), are currently used to support underwater missions that are either impossible or too risky to be performed by manned systems. In recent years the academia and robotic industry have paved paths for tackling technical challenges for ROV/AUV operations. The level of intelligence of ROV/AUV has increased dramatically because of the recent advances in low-power-consumption embedded computing devices and machine intelligence (e.g., AI). Nonetheless, operating precisely underwater is still extremely challenging to minimize human intervention due to the inherent challenges and uncertainties associated with the underwater environments. Proximity operations, especially those requiring precise manipulation, are still carried out by ROV systems that are fully controlled by a human pilot. A workplace-ready and worker-friendly ROV interface that properly simplifies operator control and increases remote operation confidence is the central challenge for the wide adaptation of ROVs.\u0000 This paper examines the recent advances of virtual telepresence technologies as a solution for lowering the barriers to the human-in-the-loop ROV teleoperation. Virtual telepresence refers to Virtual Reality (VR) related technologies that help a user to feel that they were in a hazardous situation without being present at the actual location. We present a pilot system of using a VR-based sensory simulator to convert ROV sensor data into human-perceivable sensations (e.g., haptics). Building on a cloud server for real-time rendering in VR, a less trained operator could possibly operate a remote ROV thousand miles away without losing the minimum situational awareness. The system is expected to enable an intensive human engagement on ROV teleoperation, augmenting abilities for maneuvering and navigating ROV in unknown and less explored subsea regions and works. This paper also discusses the opportunities and challenges of this technology for ad hoc training, workforce preparation, and safety in the future maritime industry. We expect that lessons learned from our work can help democratize human presence in future subsea engineering works, by accommodating human needs and limitations to lower the entrance barrier.","PeriodicalId":108360,"journal":{"name":"Day 1 Tue, February 22, 2022","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131838640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Classification in the Floating Wind Assurance","authors":"Piotr Szalewski, Robert Galinski","doi":"10.5957/tos-2022-006","DOIUrl":"https://doi.org/10.5957/tos-2022-006","url":null,"abstract":"By 2050, global installed floating wind capacity is expected to reach 264 GW. Project sanction will require levelized cost of energy (LCOE) being significantly below current levels, but also to demonstrate that the life, property, and the environment are safeguarded.\u0000 Most class societies were established in late 1800’s as independent organizations addressing technical risks in shipping industry. In 1980’s classification model has been successfully extended to the offshore oil and gas, resulting in significant safety improvements and cost savings. Most recently, the same model has been successfully applied to offshore fish farms.\u0000 During the last decades classification has been transforming towards fully risk and data driven solutions. By using fleet-wide knowledge, significant cost savings are generated and passed to the asset owner and operator. This makes classification ideally suited to floating wind.\u0000 The paper discusses areas of class society involvement in certification of floating wind foundations, including mooring system and wind turbine interface. Risk based integrity management in harsh environments the floating wind platforms are expected to operate are addressed. Potential impact is illustrated using examples from the past where such benefits were realized, including using fleet data to improve efficiencies and reduce costs. Required adaptation of classification concepts to specifics of the floating wind are also discussed.\u0000 The paper also shares examples of class society role and activities beyond certification and assurance. We hope this will help appreciate the overall value of classification provides and encourage the industry to tap into benefits from its broad knowledge and experience.","PeriodicalId":108360,"journal":{"name":"Day 1 Tue, February 22, 2022","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116376107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}