Large-Scale Aerospace Simulations using Unstructured Grid Technology

2009 ◽  
pp. 219-244
Author(s):  
N.P. Weatherill ◽  
K. Morgan ◽  
O. Hassan ◽  
J.W. Jones
Keyword(s):  
Large Scale ◽  
Unstructured Grid ◽  
Grid Technology

Sharing of Distributed Geospatial Data through Grid Technology

2010 ◽  
pp. 222-228 ◽  
Author(s):  
Yaxing Wei ◽  
Liping Di ◽  
Guangxuan Liao ◽  
Baohua Zhao ◽  
Aijun Chen ◽  
...  
Keyword(s):  
Large Scale ◽  
Storage Systems ◽  
Distributed Storage ◽  
Geospatial Data ◽  
Grid Technology ◽  
Grid System ◽  
Multiple User ◽  
User Communities ◽  
Distributed Storage Systems ◽  
Critical Requirement

With the rapid accumulation of geospatial data and the advancement of geoscience, there is a critical requirement for an infrastructure that can integrate large-scale, heterogeneous, and distributed storage systems for the sharing of geospatial data within multiple user communities. This article probes into the feasibility to share distributed geospatial data through Grid computing technology by introducing several major issues (including system heterogeneity, uniform mechanism to publish and discover geospatial data, performance, and security) to be faced by geospatial data sharing and how Grid technology can help to solve these issues. Some recent research efforts, such as ESG and the Data Grid system in GMU CSISS, have proven that Grid technology provides a large-scale infrastructure which can seamlessly integrate dispersed geospatial data together and provide uniform and efficient ways to access the data.

Problems of purification intensification of power plants in multiphase dispersed media and methods of their solution

2020 ◽  
pp. 45-54
Author(s):  
SERGIY RYZHKOV
Keyword(s):  
Power Plants ◽  
Unstructured Grid ◽  
Dispersed Phase ◽  
Grid Technology ◽  
Technical Equipment ◽  
Two Phase ◽  
Technical Problems ◽  
Study Results ◽  
The Subject ◽  
Dispersed Media

The scientfc and technical problems of the power plants improvement have been systematzed. The urgency of the problem of the power plants purifcaton in the multphase dispersed media is proved. The main purifcaton methods are analyzed, and previously unstudied pieces of problem of these processes intensifcaton are identfed. The task for the calculatons of the scheme of complex intensifcaton of the ultraturbophoretc transferal within the combined (internal and external) problem is set. The unstructured grid technology for the theoretcal calculatons of the pulsaton ultrasonic partcles depositon in the multpurpose grid coagulator is suggested and implemented. The aim of work is to develop the directons of the purifcaton intensifcaton of the dispersed multphase fows on the basis of the study results analysis. These directons are to be developed to design the technical equipment which ensures the intensifcaton of energy conservaton and environmental cleanliness of the power plants. The processes of the transferal of the fnely-dispersed phase by means of the ultrasonic and turbophoretc powers in the two-phase gas media of the power plants are the subject of the study. The scheme of complex intensifcaton of the ultraturbophoretc transferal of the micropartcles of partcles is developed within the «the inital fow secton – ultraturbophoretc grid coagulator» purifcaton system on the basis of the performed analysis of physical and mathematcal model of the process. The principles of intensifcaton of the ultraturbophoretc transferal and fnely-dispersed partcles depositon are developed. These principles are reduced to the usage of the energy potental of the dispersed two-phase media to depose the partcles; to the creaton of the acoustc vibratons gradients in the wall-adjacent areas at the surface of the channels and in the fow volume; to the generaton of turbulent pulsatons by the bodies of depositon of the multfunctonal purpose.

scholarly journals Coastal ocean forecasting with an unstructured grid model in the southern Adriatic and northern Ionian seas

2017 ◽  
Vol 17 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Ivan Federico ◽  
Nadia Pinardi ◽  
Giovanni Coppini ◽  
Paolo Oddo ◽  
Rita Lecci ◽  
...  
Keyword(s):  
Large Scale ◽  
Unstructured Grid ◽  
Tide Gauge ◽  
Coastal Ocean ◽  
Horizontal Resolution ◽  
Coastal Areas ◽  
Added Value ◽  
Surface Boundary ◽  
Open Sea ◽  
Forecasting System

Abstract. SANIFS (Southern Adriatic Northern Ionian coastal Forecasting System) is a coastal-ocean operational system based on the unstructured grid finite-element three-dimensional hydrodynamic SHYFEM model, providing short-term forecasts. The operational chain is based on a downscaling approach starting from the large-scale system for the entire Mediterranean Basin (MFS, Mediterranean Forecasting System), which provides initial and boundary condition fields to the nested system. The model is configured to provide hydrodynamics and active tracer forecasts both in open ocean and coastal waters of southeastern Italy using a variable horizontal resolution from the open sea (3–4 km) to coastal areas (50–500 m). Given that the coastal fields are driven by a combination of both local (also known as coastal) and deep-ocean forcings propagating along the shelf, the performance of SANIFS was verified both in forecast and simulation mode, first (i) on the large and shelf-coastal scales by comparing with a large-scale survey CTD (conductivity–temperature–depth) in the Gulf of Taranto and then (ii) on the coastal-harbour scale (Mar Grande of Taranto) by comparison with CTD, ADCP (acoustic doppler current profiler) and tide gauge data. Sensitivity tests were performed on initialization conditions (mainly focused on spin-up procedures) and on surface boundary conditions by assessing the reliability of two alternative datasets at different horizontal resolution (12.5 and 6.5 km). The SANIFS forecasts at a lead time of 1 day were compared with the MFS forecasts, highlighting that SANIFS is able to retain the large-scale dynamics of MFS. The large-scale dynamics of MFS are correctly propagated to the shelf-coastal scale, improving the forecast accuracy (+17 % for temperature and +6 % for salinity compared to MFS). Moreover, the added value of SANIFS was assessed on the coastal-harbour scale, which is not covered by the coarse resolution of MFS, where the fields forecasted by SANIFS reproduced the observations well (temperature RMSE equal to 0.11 °C). Furthermore, SANIFS simulations were compared with hourly time series of temperature, sea level and velocity measured on the coastal-harbour scale, showing a good agreement. Simulations in the Gulf of Taranto described a circulation mainly characterized by an anticyclonic gyre with the presence of cyclonic vortexes in shelf-coastal areas. A surface water inflow from the open sea to Mar Grande characterizes the coastal-harbour scale.

Secondary circulation in shallow ocean straits: Observations and numerical modeling of the Danish Straits

2020 ◽  
Author(s):  
Verena Haid ◽  
Emil Stanev ◽  
Johannes Pein ◽  
Joanna Staneva ◽  
Wei Chen
Keyword(s):  
Large Scale ◽  
Unstructured Grid ◽  
Secondary Circulation ◽  
Atmospheric Variability ◽  
Tidal Straining ◽  
The North ◽  
The North Sea ◽  
Similarities And Differences ◽  
Transport And Mixing ◽  
Resolution Simulation

<p>We study the secondary circulation in the Danish Straits using the unstructured-grid hydrodynamic model SCHISM covering the North Sea and Baltic Sea. The resolution in the straits is up to ~100 m. Since the large-scale atmospheric variability controls the transport in these straits, we focus on the processes with subtidal time scales. We compare the in- and outflows in the straits to flood and ebb flows in estuaries and analyze similarities and differences. Very prominently, the outflow and inflow phases of the Danish Straits feature substantial differences to the tidal straining in estuaries. With a resolution of ~100 m, new transport and mixing pathways, previously unresolved, appear fundamental to the strait dynamics. The variability of the strait bathymetry leads to a strongly differing appearance of secondary circulation. Helical cells, often with a horizontal extension of ~1 km, develop in the deep parts of the channels. A comparison between the high-resolution simulation and a simulation with a coarser grid of ~500 m in the straits suggests that the coarser resolution overestimates the stratification and misrepresents the transport balance. Axial velocities and transport through the Sound are underestimated by ~12%. These differences are explained by the underdeveloped secondary circulation in the coarse-resolution simulation and the associated changes in mixing along the straits. In conclusion, the use of ultrafine resolution grids is essential to adequately resolve secondary flow patterns and two-layer exchange.</p>

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