scholarly journals Utilizing MIKE 21 Software to Create Simple Hydrodynamic Simulations

2021 ◽  
Vol 2 (1) ◽  
pp. 14-17
Author(s):  
Subiyanto Subiyanto ◽  
Sudradjat Supian
Keyword(s):  
Coastal Areas ◽  
Climatic Data ◽  
Coastal Morphology ◽  
Hydrodynamic Simulation ◽  
Hydrodynamic Simulations ◽  
Line Theory ◽  
Shoreline Dynamics ◽  
The Cross ◽  
Coastal Profile ◽  
Mike 21

This paper aim to create simple hydrodynamic simulation by using MIKE 21. The module used in MIKE 21 is LITPACK. LITPACK is one of the modules in MIKE 21 to solve hydraulic and sedimentation problems in coastal areas. Especially in this paper, the LITTLITE engine in LITPACK will be used. LITLINE determines the coastline position using a timeseries of wave climatic data. The model is based on a one-line theory, in which the cross-shore profile is expected to remain unaltered during erosion/accretion, with minor adjustments. Coastal morphology is thus only defined by coastline location (cross-shore direction) and coastal profile at a given long-shore position. The simulation used in this paper is the influence of groins on shoreline dynamics. The results of the simulation show that some areas will experience abrasion and some will experience accretion. 

scholarly journals Study of the influence of initial-state fluctuations on hydrodynamic simulations

2020 ◽  
Vol 245 ◽  
pp. 06005
Author(s):  
Marcin Słodkowski ◽  
Patryk Gawryszewski ◽  
Dominik Setniewski
Keyword(s):  
Initial Conditions ◽  
Graphics Processing Unit ◽  
Heavy Ion ◽  
Processing Unit ◽  
Initial State ◽  
Final State ◽  
Hydrodynamic Simulation ◽  
Hydrodynamic Simulations ◽  
Cartesian Coordinate ◽  
Ion Collision

In this work, we are focusing on assessing the contribution of the initial-state fluctuations of heavy ion collision in the hydrodynamic simulations. We are trying to answer the question of whether the hydrodynamic simulation retains the same level of fluctuation in the final-state as for the initial stage. In another scenario, the hydrodynamic simulations of the fluctuation drowns in the final distribution of expanding matter. For this purpose, we prepared sufficient relativistic hydrodynamic program to study A+A interaction which allows analysing initial-state fluctuations in the bulk nuclear matter. For such an assumption, it is better to use high spatial resolution. Therefore, we applied the (3+1) dimensional Cartesian coordinate system. We implemented our program using parallel computing on graphics cards processors - Graphics Processing Unit (GPU). Simulations were carried out with various levels of fluctuation in initial conditions using the average method of events coming from UrQMD models. Energy density distributions were analysed and the contribution of fluctuations in initial conditions was assessed in the hydrodynamic simulation.

scholarly journals What Determines the Parameters of a Propagating Streamer: A Comparison of Outputs of the Streamer Parameter Model and of Hydrodynamic Simulations

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1664
Author(s):  
Nikolai G. Lehtinen ◽  
Robert Marskar
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Electric Discharge ◽  
Propagation Velocity ◽  
The Novel ◽  
Hydrodynamic Simulation ◽  
Hydrodynamic Simulations ◽  
Important Stage ◽  
Streamer Discharges

Electric streamer discharges (streamers) in the air are a very important stage of lightning, taking place before formation of the leader discharge, and with which an electric discharge starts from conducting objects which enhance the background electric field, such as airplanes. Despite years of research, it is still not well understood what mechanism determines the values of a streamer’s parameters, such as its radius and propagation velocity. The novel Streamer Parameter Model (SPM) was made to explain this mechanism, and to provide a way to efficiently calculate streamer parameters. Previously, we demonstrated that SPM results compared well with a limited set of experimental data. In this article, we compare SPM predictions to the published hydrodynamic simulation (HDS) results.

scholarly journals PROCESS-BASED MODELING OF COASTAL DUNE DEVELOPMENT

2012 ◽  
Vol 1 (33) ◽  
pp. 33
Author(s):  
Martijn Christiaan Muller ◽  
Dano Roelvink ◽  
Arjen Luijendijk ◽  
Sierd De Vries ◽  
Jaap Van Thiel de Vries
Keyword(s):  
Transport Model ◽  
Coastal Areas ◽  
Coastal Dune ◽  
Aeolian Transport ◽  
Final Model ◽  
Model Version ◽  
Coastal Profile ◽  
Desert Dunes

In this paper, the aeolian transport model DUNE (Sauermann et al., 2001, Kroy et al., 2002) that describes important features and dynamics of typical desert dunes, is extended such that it can be applied in sandy coastal areas. Initial tests explore the limitations of the model in coastal areas after which adaptations are proposed and implemented. The final model version is applied to a coastal profile near Vlugtenburg (Dutch Holland coast).

scholarly journals Analysis of Abrasion in Coastal Areas of North Bengkulu Beach as Learning Material for Disaster Mitigation

2020 ◽  
Vol 1 (2) ◽  
pp. 55-60
Author(s):  
Jenny Maya Yazalia ◽  
Henny Johan ◽  
Rendy W. Wardana
Keyword(s):  
Wave Height ◽  
Soil Structure ◽  
Coastal Region ◽  
Coastal Areas ◽  
Disaster Mitigation ◽  
Learning Material ◽  
Coastal Morphology ◽  
The North ◽  
Qualitative Descriptive ◽  
The Difference

The threat of disasters that often occur in coastal areas is seawater abrasion. One of the provinces in Indonesia which is located in the coastal region is Bengkulu with the area most prone to abrasion disaster is the North Bengkulu Regency. This study aims to describe the potential for abrasion in the North Bengkulu region based on the parameters of abrasion vulnerability. The research method used is a qualitative descriptive method with literature studies. An abrasion potential analysis has been carried out based on the measurement of three parameters of abrasion susceptibility namely coastal morphology, soil structure and wave height. The results showed that the coastal morphology in the area of North Bengkulu Regency was strongly influenced by tectonic processes that occur due to subduction zone pressure. Coastal morphology in the form of steep cliffs, piles (stack), while on steep cliffs also formed beach caves. The soil structure on a coastal cliff shows that the dominant cliff is composed of sandstones, gravel, clay and alluvium. The difference in vertical rock resistance results in the beach being prone to abrasion. The wave height (swash) in the North Bengkulu regency is an average of 60 cm, although at certain locations the swash height reaches 85 cm. Thus, it can be concluded that the area of North Bengkulu regency is very potential for abrasion and efforts are needed to reduce it, one of the ways through disaster mitigation education.

scholarly journals Hybrid analytic and machine-learned baryonic property insertion into galactic dark matter haloes

2021 ◽  
Author(s):  
Ben Moews ◽  
Romeel Davé ◽  
Sourav Mitra ◽  
Sultan Hassan ◽  
Weiguang Cui
Keyword(s):  
Machine Learning ◽  
Dark Matter ◽  
High Speed ◽  
Hydrodynamic Simulation ◽  
Hydrodynamic Simulations ◽  
Learning Framework ◽  
Advantages And Disadvantages ◽  
Reasonable Degree ◽  
Galactic Dark Matter ◽  
Speed Advantage

Abstract While cosmological dark matter-only simulations relying solely on gravitational effects are comparably fast to compute, baryonic properties in simulated galaxies require complex hydrodynamic simulations that are computationally costly to run. We explore the merging of an extended version of the equilibrium model, an analytic formalism describing the evolution of the stellar, gas, and metal content of galaxies, into a machine learning framework. In doing so, we are able to recover more properties than the analytic formalism alone can provide, creating a high-speed hydrodynamic simulation emulator that populates galactic dark matter haloes in N-body simulations with baryonic properties. While there exists a trade-off between the reached accuracy and the speed advantage this approach offers, our results outperform an approach using only machine learning for a subset of baryonic properties. We demonstrate that this novel hybrid system enables the fast completion of dark matter-only information by mimicking the properties of a full hydrodynamic suite to a reasonable degree, and discuss the advantages and disadvantages of hybrid versus machine learning-only frameworks. In doing so, we offer an acceleration of commonly deployed simulations in cosmology.

scholarly journals BEACH FILL AT TWO COASTS OF DIFFERENT CONFIGURATIONS

1986 ◽  
Vol 1 (20) ◽  
pp. 77
Author(s):  
Ichiro Deguchi ◽  
Toru Sawaragi
Keyword(s):  
Dissipation Rate ◽  
Clear Correlation ◽  
Submerged Breakwater ◽  
Topographic Data ◽  
Line Theory ◽  
The Cross

Movements of borrow sand replenished at two coasts of different configurations are investigated by analyzing the topographic data which were surveyed periodically after the beach fill placements. One is a long straight beach and borrow sand was placed behind a submerged breakwater. Another is a pocket beach which has an arcshoreline with a groyne at one end and a headland at another. It is found that the amount of borrow sand moved in the longshore direction surpasses the amount of borrow sand transported in the cross-shore direction regardless of the shape of the coast. A clear correlation is also found between displacements of shoreline and changes of sectional areas. These results imply that the deformation of the artificially nourished beach and the dissipation rate of borrow sand can be predicted by the so-called one-line theory.

scholarly journals Climatic influences on the worldwide spread of SARS-CoV-2

2020 ◽  
Author(s):  
Michail Bariotakis ◽  
George Sourvinos ◽  
Elias Castanas ◽  
Stergios A. Pirintsos
Keyword(s):  
Transmission Rate ◽  
Coastal Areas ◽  
Climatic Data ◽  
Climatic Impact ◽  
Major Health Problem ◽  
Preventive Vaccine ◽  
Bioclimatic Variables ◽  
Social Scene ◽  
Calculated Probability ◽  
The Tropics

AbstractThe rapid global spread of the novel, pathogenic, SARS-CoV-2 causing the severe acute respiratory disease COVID-19, becomes a major health problem worldwide and pose the need for international predictive programs. Given the lack of both specific drugs and an efficient preventive vaccine, the expectation that SARS-CoV-2’s transmission rate might decrease in temperate regions during summer, dominated the social scene. Here, we attempted a prediction of the worldwide spread of the infections based on climatic data, expressed by 19 bioclimatic variables. The calculated probability maps shown that potential areas of infection follow a shift from the Tropical to Temperate and Mediterranean Bioclimatic regions, and back to the Tropics again. Maps show an increased probability of infections in Europe, followed by an expansion covering areas of the Middle East and Northern Africa, as well as Eastern coastal areas of North America, South-Eastern coastal areas of Latin America and two areas of Southern Australia, and later return to areas of Southeastern Asia, in a manner similar to that of influenza strains (H3N2). Our approach may therefore be of value for the worldwide spread of SARS-CoV-2, suggesting an optimistic scenario of asynchronous seasonal global outbreaks, like other viral respiratory diseases. Consequently, we suggest the incorporation of a climatic impact in the design and implementation of public health policies. Maps of our model are available (constantly updated up to the saturation of the model) at: https://navaak.shinyapps.io/CVRisk/.

scholarly journals Reproducing sub-millimetre galaxy number counts with cosmological hydrodynamic simulations

2021 ◽  
Author(s):  
Christopher C Lovell ◽  
James E Geach ◽  
Romeel Davé ◽  
Desika Narayanan ◽  
Qi Li
Keyword(s):  
Galaxy Evolution ◽  
Galaxy Formation ◽  
Formation Rate ◽  
Small Contribution ◽  
Redshift Distribution ◽  
Hydrodynamic Simulation ◽  
Hydrodynamic Simulations ◽  
Multiple Components ◽  
Number Counts ◽  
Good Agreement

Abstract Matching the number counts of high-z sub-millimetre-selected galaxies (SMGs) has been a long standing problem for galaxy formation models. In this paper, we use 3D dust radiative transfer to model the sub-mm emission from galaxies in the Simba cosmological hydrodynamic simulations, and compare predictions to the latest single-dish observational constraints on the abundance of 850 μm-selected sources. We find good agreement with the shape of the integrated 850 μm luminosity function, and the normalisation is within 0.25 dex at >3 mJy, unprecedented for a fully cosmological hydrodynamic simulation, along with good agreement in the redshift distribution of bright SMGs. The agreement is driven primarily by Simba’s good match to infrared measures of the star formation rate (SFR) function between z = 2 − 4 at high SFRs. Also important is the self-consistent on-the-fly dust model in Simba, which predicts, on average, higher dust masses (by up to a factor of 2.5) compared to using a fixed dust-to-metals ratio of 0.3. We construct a lightcone to investigate the effect of far-field blending, and find that 52% of sources are blends of multiple components, which makes a small contribution to the normalisation of the bright-end of the number counts. We provide new fits to the 850 μm luminosity as a function of SFR and dust mass. Our results demonstrate that solutions to the discrepancy between sub-mm counts in simulations and observations, such as a top-heavy IMF, are unnecessary, and that sub-millimetre-bright phases are a natural consequence of massive galaxy evolution.

Reconstruction of ice flow across the Bunger Hills, East Antarctica

1997 ◽  
Vol 9 (3) ◽  
pp. 347-354 ◽  
Author(s):  
Paul C. Augustinus ◽  
Damian B. Gore ◽  
Michelle R. Leishman ◽  
Dan Zwartz ◽  
Eric A. Colhoun
Keyword(s):  
Flow Direction ◽  
Ice Sheet ◽  
Coastal Areas ◽  
East Antarctica ◽  
Late Cenozoic ◽  
Ice Flow ◽  
North East ◽  
The North ◽  
Free Region ◽  
The Cross

In the Bunger Hills, mapping of glacial drift sheets and examination of striae patterns and other palaeo-ice flow direction indicators show that the largely ice-free region records the imprint of ice sheet expansion(s) during the late Cenozoic. In particular, ice moulded features and striae in southern Bunger Hills suggest formation during at least two episodes of ice sheet expansion, although whether they were formed during separate events or merely different phases of the same expansion of the ice sheet is not able to be discerned at present. The older event relates to thin ice with flow constrained by the topography, whilst the younger event relates to regional expansion of thick ice across the area. Discrimination of the order of emplacement of the cross-cutting striae patterns is possible at a number of sites. Palaeo-ice flow indicators confirm that ice sheet expansion over southern Bunger Hills was purely from the southern and eastern margins, although minor advances of the north-east flowing Edisto Glacier onto coastal areas occurred following retreat of the last extensive ice sheet phase.

scholarly journals Effects of radiation pressure on the evaporative wind of HD 209458b

2020 ◽  
Vol 493 (1) ◽  
pp. 1292-1305 ◽  
Author(s):  
Alex Debrecht ◽  
Jonathan Carroll-Nellenback ◽  
Adam Frank ◽  
Eric G Blackman ◽  
Luca Fossati ◽  
...  
Keyword(s):  
Radiation Pressure ◽  
High Energy ◽  
Line Of Sight ◽  
Hydrodynamic Simulation ◽  
High Energy Radiation ◽  
Hydrodynamic Simulations ◽  
Cometary Tail ◽  
Effects Of Radiation ◽  
Simplified Calculation

ABSTRACT The role of radiation pressure in shaping exoplanet photoevaporation remains a topic of contention. Radiation pressure from the exoplanet’s host star has been proposed as a mechanism to drive the escaping atmosphere into a ‘cometary’ tail and explain the high velocities observed in systems where mass-loss is occurring. In this paper, we present results from high-resolution 3D hydrodynamic simulations of a planet similar to HD 209458b. We self-consistently launch a wind flowing outwards from the planet by calculating the ionization and heating resulting from incident high-energy radiation, and account for radiation pressure. We first present a simplified calculation, setting a limit on the Lyman-α flux required to drive the photoevaporated planetary material to larger radii and line-of-sight velocities. We then present the results of our simulations, which confirm the limits determined by our analytic calculation. We thus demonstrate that, within the limits of our hydrodynamic simulation and for the Lyman-α fluxes expected for HD 209458, radiation pressure is unlikely to significantly affect photoevaporative winds or to explain the high velocities at which wind material is observed, though further possibilities remain to be investigated.

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