Browsing by Author "Zhang, Jiaye"
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Item Eulerian two-phase modeling of wave orbital ripples: a sensitivity study on closure models(University of Delaware, 2021) Zhang, JiayeA two-dimensional simulation of sediment transport over wave orbital ripples driven by onshore velocity-skewed oscillatory flow using a Eulerian two-phase flow model, SedFoam, is presented to investigate the sensitivity of the turbulence closure models with respect to sediment transport and ripple migration. The comparison of simulation results between k-ɛ model and k-ω SST model at equilibrium stage confirms that the k-ω SST model predicts a significantly weaker vortices evolution in orbital ripple field, which causes less suspended sediment transport during a wave period. The resulting equilibrium ripple steepness is also under-predicted. An in-depth analysis reveals that the negative component of cross-diffusion term neglected in k-ω SST model results in weaker turbulence and lower turbulent suspension. Hence, a larger onshore near-bed sediment transport and a smaller offshore suspended load transport are obtained. Consequently, the model with k-ω SST closure over-predicts the onshore ripple migration rate. The root cause of which the neglected negative cross-diffusion term leads to the under-prediction of primary vortices on the ripple flanks under oscillatory flows is worth of further investigation.Item Proceedings of the 2024 DARWIN Computing Symposium(Data Science Institute of the University of Delaware, 2024-02-12) Hsu, Tian-Jian; Bagozzi, Benjamin E.; Eigenmann, Rudolf; Jayaraman, Arthi; Totten, William; Wu, Cathy H.; Blaustein, Michael; Blinova, Daria; Carney, Lynette; Huffman, John; Smith, Samantha; Zhang, JiayeThe DARWIN Computing Symposium 2024—sponsored by the Data Science Institute (DSI) of the University of Delaware—was held on February 12, 2024. It represented the fifth event in a series of Symposia motivated by a National Science Foundation (NSF) MRI Award, also known as the Delaware Advanced Research Workforce and Innovation Network (DARWIN). As part of an NSF Major Research Instrumentation award (OAC-1919839), DARWIN focuses on catalyzing "research and education at the University of Delaware (UD) and partners by acquiring a big data and high-performance computing system and making this instrument available to the community." In an effort to identify and advance future computing needs for artificial intelligence, to reduce the overhead for domain scientists utilizing HPC, and to develop regional partnerships, this fifth DARWIN Computing Symposium more specifically featured a panel and a keynote talk, as well as a series of research talks on DARWIN-enabled research, on computational and data-intensive (CDI) research/training needs, and on AI-focused CDI research more generally. These talks highlighted the use of AI in HPC to advance sciences and predictive capabilities with societal relevance across a wide range of domains. A panel discussion then facilitated interactions between research software engineers and domain scientists with an eye towards advancing scientific progress in different disciplines. In addition, 30 poster presentations by students and postdocs highlighted a number of relevant CDI research projects. Alongside the NSF and the Data Science Institute, the 2023 DARWIN Computing Symposium was sponsored by Tech Impact, UD’s Delaware Environmental Institute, UD’s Center for Applied Coastal Research, UD Information Technologies, and the University of Delaware Faculty Senate. Dr. Tian-Jian Hsu, University of Delaware Professor of Civil & Environmental Engineering and Director of the Center for Applied Coastal Research served as chair of the 2024 DARWIN Computing Symposium.