scholarly journals Numerical Simulations of Flow around Copepods: Challenges and Future Directions

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 52
Author(s):  
Iman Borazjani
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Vital Role ◽  
The Body ◽  
Marine Ecology ◽  
Small Scale ◽  
Mate Finding ◽  
Future Directions ◽  
Form Function ◽  
Different Parts

Copepods are small aquatic creatures which are abundant in oceans as a major food source for fish, thereby playing a vital role in marine ecology. Because of their role in the food chain, copepods have been subject to intense research through different perspectives from anatomy, form-function biology, to ecology. Numerical simulations can uniquely support such investigations by quantifying: (i) the force and flow generated by different parts of the body, thereby clarify the form-function relation of each part; (ii) the relation between the small-scale flow around animal and the large-scale (e.g., oceanic) flow of its surroundings; and (iii) the flow and its energetics, thereby answering ecological questions, particularly, the three major survival tasks, i.e., feeding, predator avoidance, and mate-finding. Nevertheless, such numerical simulations need to overcome challenges involving complex anatomic shape of copepods, multiple moving appendages, resolving different scales (appendage-, animal- to large-scale). The numerical methods capable of handling such problems and some recent simulations are reviewed. At the end, future developments necessary to simulate copepods from animal- to surrounding-scale are discussed.

scholarly journals Unorthodox: An ancient tradition - A contemporary context

2021 ◽  
Author(s):  
◽  
Anne Isaac
Keyword(s):  
New Zealand ◽  
Large Scale ◽  
Vital Role ◽  
The Body ◽  
Small Scale ◽  
Migrant Communities ◽  
Close Relationship ◽  
Sense Of Identity ◽  
Church Design ◽  
The Impact

<p>For decades, New Zealand historians and architects have sought answers to the question: What is New Zealand architecture? New Zealand longs for a place in the architectural world, seeking the significance of our buildings in the wider realm of world architecture. In 2016, in a presentation based on his book Worship: a history of New Zealand church design, Bill McKay suggested that perhaps, “our most interesting architecture lies in the intersections of our cultures”.  An opportunity is offered by the current shifts of New Zealand society where the impact of immigration on society is one of the most pressing issues that currently needs addressing. This thesis endeavours to explore the specific relationship between the heritage and culture of the existing Assyrian community and its context of Wellington, with reference to McKay’s suggestion that our most interesting architecture is birthed from the intersection of different cultures.  Socially speaking, sense of identity and place attachment play a vital role in the integration of migrant communities into their new home country. Recalling and employing elements of not only tangible Assyrian heritage, but also the intangible qualities found in traditional Assyrian architecture, has the potential to create the connection and enhance the sense of identity which allows for the feeling of belonging in migrants in their host society. This thesis focuses on the space of worship.   This project of an Assyrian Orthodox church building in New Zealand might reflect the life of the migrants who occupy it. Is it a replica of the traditional building in its original context, unchanged and uninfluenced by the shift to a new place? Or is it influenced and integrated; a building which can identify with the soil it stands on? Furthermore, if one considers that architecture reflects society, it is hoped that this design led research will participate in the discussion about New Zealand architecture’s unique identity and emerging new societal makeup.  This design led research discovers that creating a sense of belonging relies on both keeping aspects of the traditional and gaining influence from its new context. As focus shifts from the design of the building at a large scale to details and objects at a small scale, it becomes more important to reflect and retain the traditional qualities of the architecture. At a large scale, the building may be influenced by its context so as to be integrated into its new place, as if it belongs within its new urban fabric. As we move into the smaller scale in design, we draw closer to the body. It is these elements of the design which an occupant experiences more intimately, and through sensory experience and triggering memories of home, can help to create a feeling of belonging. The main findings of this research express the close relationship between architectural scales of intervention and the effects of individual and collective memory.</p>

scholarly journals Unorthodox: An ancient tradition - A contemporary context

2021 ◽  
Author(s):  
◽  
Anne Isaac
Keyword(s):  
New Zealand ◽  
Large Scale ◽  
Vital Role ◽  
The Body ◽  
Small Scale ◽  
Migrant Communities ◽  
Close Relationship ◽  
Sense Of Identity ◽  
Church Design ◽  
The Impact

<p>For decades, New Zealand historians and architects have sought answers to the question: What is New Zealand architecture? New Zealand longs for a place in the architectural world, seeking the significance of our buildings in the wider realm of world architecture. In 2016, in a presentation based on his book Worship: a history of New Zealand church design, Bill McKay suggested that perhaps, “our most interesting architecture lies in the intersections of our cultures”.  An opportunity is offered by the current shifts of New Zealand society where the impact of immigration on society is one of the most pressing issues that currently needs addressing. This thesis endeavours to explore the specific relationship between the heritage and culture of the existing Assyrian community and its context of Wellington, with reference to McKay’s suggestion that our most interesting architecture is birthed from the intersection of different cultures.  Socially speaking, sense of identity and place attachment play a vital role in the integration of migrant communities into their new home country. Recalling and employing elements of not only tangible Assyrian heritage, but also the intangible qualities found in traditional Assyrian architecture, has the potential to create the connection and enhance the sense of identity which allows for the feeling of belonging in migrants in their host society. This thesis focuses on the space of worship.   This project of an Assyrian Orthodox church building in New Zealand might reflect the life of the migrants who occupy it. Is it a replica of the traditional building in its original context, unchanged and uninfluenced by the shift to a new place? Or is it influenced and integrated; a building which can identify with the soil it stands on? Furthermore, if one considers that architecture reflects society, it is hoped that this design led research will participate in the discussion about New Zealand architecture’s unique identity and emerging new societal makeup.  This design led research discovers that creating a sense of belonging relies on both keeping aspects of the traditional and gaining influence from its new context. As focus shifts from the design of the building at a large scale to details and objects at a small scale, it becomes more important to reflect and retain the traditional qualities of the architecture. At a large scale, the building may be influenced by its context so as to be integrated into its new place, as if it belongs within its new urban fabric. As we move into the smaller scale in design, we draw closer to the body. It is these elements of the design which an occupant experiences more intimately, and through sensory experience and triggering memories of home, can help to create a feeling of belonging. The main findings of this research express the close relationship between architectural scales of intervention and the effects of individual and collective memory.</p>

Effects of interactions between transient granular flows and macroscopically rough beds and their implications for bulk flow dynamics

2021 ◽  
Author(s):  
Clarence E. Choi ◽  
George Robert Goodwin
Keyword(s):  
Bulk Density ◽  
Large Scale ◽  
The Body ◽  
Flow Dynamics ◽  
Small Scale ◽  
Mobility Models ◽  
Flow Front ◽  
Physical Tests ◽  
Unit Depth ◽  
Rough Beds

Steep-creek beds are macroscopically rough. This roughness causes channelised flow material to decelerate and dissipate energy, which are accounted for by depth-averaged mobility models (DMM). However, practical DMM implementations do not explicitly account for grain-scale basal interactions which influence macroscopic flow dynamics. In this study, we model flows using physical tests with smooth and macroscopically rough bases, and hence evaluate Discrete Element Method (DEM) and DMM models. A scaling effect is identified relating to roughened beds: increasing the number of grains per unit depth tends to suppress dispersion, such that small-scale flows on smooth beds resemble large-scale flows on roughened beds, at least in terms of bulk density. Furthermore, the DEM shows that rougher beds reduce the peak bulk density by up to 15% compared to a smooth bed. Rough beds increase the vertical momentum transfer tenfold, compared to smooth ones. The DMM cannot account for density change or vertical momentum, so DMM flow depths are underestimated by 90% at the flow front and 20% in the body. The Voellmy model implicitly captures internal energy dissipation for flows on rough beds. The parameter ξ can allow velocity reductions due to rough beds observed in the DEM to be captured.

scholarly journals A severe blizzard event in Romania – a case study

2009 ◽  
Vol 9 (2) ◽  
pp. 623-634 ◽  
Author(s):  
F. Georgescu ◽  
S. Tascu ◽  
M. Caian ◽  
D. Banciu
Keyword(s):  
Numerical Simulations ◽  
Time Scale ◽  
Large Scale ◽  
Forecast Accuracy ◽  
Horizontal Resolution ◽  
Maximum Temperature ◽  
Small Scale ◽  
Relative Role ◽  
Snow Layer ◽  
Strong Winds

Abstract. During winter cold strong winds associated with snowfalls are not unusual for South and Southeastern Romania. The episode of 2–4 January 2008 was less usual due to its intensity and persistence. It happened after a long period (autumn 2006–autumn 2007) of mainly southerly circulations inducing warm weather, when the absolute record of the maximum temperature was registered. The important snowfalls and snowdrifts, leading to a consistent snow layer (up to 100 cm), produced serious transport and electricity supply perturbations. Since this atypical local weather event was not correctly represented by the operational numerical forecasts, several cross-comparison numerical simulations were performed to analyze the relative role of the coupler/coupling models and to compare two ways of process-scale uncertainties mitigation: optimizing the forecast range and performing ensemble forecast through the perturbation of the lateral boundary conditions. The results underline, for this case, the importance of physical parametrization package on the first place and secondary, the importance of the model horizontal resolution. The resolution increase is beneficial only in the local process representation; on larger scale it may either improve or decrease the accuracy effect, depending on the specified nudging between large-scale and small-scale information. The event capture is likely to be favored by two elements: a more appropriate time-scale of the event's physics and the quality of the transmitted large-scale information. Concerning the time scale, the statistics on skill as a function of forecast range are shown to be a useful tool in order to increase the accuracy of the numerical simulations. Ensembles forecasting versus resolution increase experiments indicate, for such atypical events, an interesting supply in the forecast accuracy through the ensemble method when applied to correct the minimum skill of the deterministic forecast.

scholarly journals The fate of random initial vorticity distributions for two-dimensional Euler equations on a sphere

2015 ◽  
Vol 786 ◽  
pp. 1-4 ◽  
Author(s):  
Paul K. Newton
Keyword(s):  
Numerical Simulations ◽  
Euler Equations ◽  
Large Scale ◽  
Initial Conditions ◽  
Infinite Family ◽  
Small Scale ◽  
Two Dimensional ◽  
Random Initial Conditions ◽  
Long Time ◽  
Initial Vorticity

The paper by Dritschel et al. (J. Fluid Mech., vol. 783, 2015, pp. 1–22) describes the long-time behaviour of inviscid two-dimensional fluid dynamics on the surface of a sphere. At issue is whether the flow settles down to an equilibrium or whether, for generic (random) initial conditions, the long-time solution is periodic, quasi-periodic or chaotic. While it might be surprising that this issue is not settled in the literature, it is important to keep in mind that the Euler equations form a dissipationless Hamiltonian system, hence the set of equations only redistributes the initial vorticity, generating smaller and smaller scales, while keeping kinetic energy, angular impulse and an infinite family of vorticity moments (Casimirs) intact. While special solutions that never settle down to an equilibrium state can be constructed using point vortices, vortex patches and other distributions, the fate of random initial conditions is a trickier problem. Previous statistical theories indicate that the long-time state should be a stationary large-scale distribution of vorticity. By carrying out careful numerical simulations using two different methods, the authors make a compelling case that the generic long-time state resembles a large-scale oscillating quadrupolar vorticity field, surrounded by persistent small-scale vortices. While numerical simulations can never conclusively settle this issue, the results might help guide future theories that seek to prove the existence of such an interesting dynamical long-time state.

On the vorticity transport due to dissipating or breaking waves in shallow-water flow

2000 ◽  
Vol 407 ◽  
pp. 235-263 ◽  
Author(s):  
OLIVER BÜHLER
Keyword(s):  
Numerical Simulations ◽  
Shallow Water ◽  
Gravity Waves ◽  
Large Scale ◽  
Bottom Topography ◽  
Breaking Waves ◽  
Small Scale ◽  
Practical Consideration ◽  
Mean Flow ◽  
Vorticity Transport

Theoretical and numerical results are presented on the transport of vorticity (or potential vorticity) due to dissipating gravity waves in a shallow-water system with background rotation and bottom topography. The results are obtained under the assumption that the flow can be decomposed into small-scale gravity waves and a large-scale mean flow. The particle-following formalism of ‘generalized Lagrangian-mean’ theory is then used to derive an ‘effective mean force’ that captures the vorticity transport due to the dissipating waves. This can be achieved without neglecting other, non-dissipative, effects which is an important practical consideration. It is then shown that the effective mean force obeys the so-called ‘pseudomomentum rule’, i.e. the force is approximately equal to minus the local dissipation rate of the wave's pseudomomentum. However, it is also shown that this holds only if the underlying dissipation mechanism is momentum-conserving. This requirement has important implications for numerical simulations, and these are discussed.The novelty of the results presented here is that they have been derived within a uniform theoretical framework, that they are not restricted to small wave amplitude, ray-tracing or JWKB-type approximations, and that they also include wave dissipation by breaking, or shock formation. The theory is tested carefully against shock-capturing nonlinear numerical simulations, which includes the detailed study of a wavetrain subject to slowly varying bottom topography. The theory is also cross-checked in the appropriate asymptotic limit against recently formulated weakly nonlinear theories. In addition to the general finite-amplitude theory, detailed small-amplitude expressions for the main results are provided in which the explicit appearance of Lagrangian fields can be avoided. The motivation for this work stems partly from an on-going study of high-altitude breaking of internal gravity waves in the atmosphere, and some preliminary remarks on atmospheric applications and on three-dimensional stratified versions of these results are given.

Smart Pigging in High Pressure Gas Pipeline Practical Problems and Solutions: A Case Study

2013 ◽  
Author(s):  
Jegadeesh Nagaraj
Keyword(s):  
Power Plants ◽  
Large Scale ◽  
Data Retrieval ◽  
Vital Role ◽  
Small Scale ◽  
Problems And Solutions ◽  
City Gas ◽  
Transmission Pipeline ◽  
Integrity Management ◽  
Pig Performance

Smart pigs, also known as inline inspection (ILI) tools or intelligent pigs, are electronic devices designed to flow on the inside of a gas transmission pipeline, usually while the line is in service, to inspect a pipeline for various types of anomalies that can increase the risks of pipeline failure. This paper describes various problems faced on in service pigging in gas pipelines even after getting data by typical pipeline questionnaire as per NACE RP0102. Problems and solution starting from Launching, crossing SV stations, tap off Point flow tees and Receiving at Pig Receiver including data retrieval from smart pig. First of all, different segment thickness and anomalies of entire length of pipeline will be studied before launch of the tool, because this is important input in ILI tool design in terms of OD and percentage flexibility of pig while run. API 1163 will considered as a master standard for smart pig applications in pipelines. Smart pigging is done once in 10 years interval as per Indian regulation and data recorded in this inspection is important risk assessment input in Pipeline Integrity Management and for deciding life of pipeline. This paper describes various problem faced in pigging i.e. Pig struck before Launching in Launcher, Pig struck at Sectionalization Valve station, Pig stopped in Pipeline without any reason, Pig struck at Flow Tee before Receiver, Pig barrel opening a Hazardous activity, Failure of Data retrieval from smart pig after receiving, Re-run of smart pig and how fluctuating flow rates in different region of pipelines will affect running a pig. This paper deals pig retrieval methods used in different struck ups and various aspects to be considered while planning to run a smart pig. This paper also deals problem faced i.e. magnetized pipe and difficulty in welding after retrieving struck up pigs by hot tapping and stoppling methods and how it was solved. Smart pigging, when properly applied, can serve as a superior inspection tool for many risks of concern over other integrity inspection methods. A proper smart pigging program can play a vital role in integrity management (“IM”) and smooth operation of pipeline without any flow interruption to downstream customers. The downstream customers of different industry which serves to run day to day life of society like Power Plants, City Gas Distribution (CGD) Companies, Refineries, Fertilizers, Ceramics, Dairy units etc will not be interrupted while run a smart pig to avoid consequences and give better service as a Pipeline operator. Smart pig, performance specification shall be qualified by the service provider by any one of the methodologies i.e. verified historical data, Large scale tests from real or artificial anomalies, small scale tests, modeling, and/or analyses. Pipeline operator may ensure final documents and other requirements as per API1163 standards.

Overview of Accelerator Applications in Energy

2015 ◽  
Vol 08 ◽  
pp. 1-25 ◽  
Author(s):  
Robert W. Garnett ◽  
Richard L. Sheffield
Keyword(s):  
Large Scale ◽  
Oil And Gas ◽  
High Energy ◽  
Small Scale ◽  
Future Directions ◽  
Industrial Systems ◽  
Large Scale Systems ◽  
Oil And Gas Exploration ◽  
Exploration And Production ◽  
Accelerator Technology

An overview of the application of accelerators and accelerator technology in energy is presented. Applications span a broad range of cost, size, and complexity and include large-scale systems requiring high-power or high-energy accelerators to drive subcritical reactors for energy production or waste transmutation, as well as small-scale industrial systems used to improve oil and gas exploration and production. The enabling accelerator technologies will also be reviewed and future directions discussed.

scholarly journals OPPORTUNITIES OF TOURISM RELATED SMALL SCALE INDUSTRIES IN INDIA: IN SPECIAL REFERENCE TO VARANASI

2019 ◽  
Vol 15 (01) ◽  
Author(s):  
Abhishek Kumar Nigam ◽  
Akriti Jaiswal ◽  
Vivek Kumar
Keyword(s):  
Special Reference ◽  
Large Scale ◽  
Vital Role ◽  
The Other ◽  
Standard Of Living ◽  
Small Scale ◽  
The People ◽  
Tourism Sector ◽  
Different Dimensions ◽  
Small Scale Industries

Small Scale Industries play a crucial role in the development of any country and contributes significantly in the economic development of the country. In a developing country like India where large scale industries are restricted to a few hands, Small Scale Industries play a vital role in the development of the country by providing employment, innovation and improving the standard of living of the people. By focusing on the different dimensions and identifying new dimensions of SSI in India, we can boost up the economic growth of the country as a whole. Tourism on the other hand is an important factor and contributor in the income of a country and its state. India is rich in cultural heritage and the huge diversity of India consisting of cultural believes and tourist places that attract a large number of national and international tourists across the globe every year. This gives birth to some new businesses in that state, provides numerous employment avenues, brings in foreign currencies as well as contributes in the total exports of the country. This paper deals with studying the prospective growth and opportunities of Small Scale Industries related to the tourism sector and identifying and suggesting measures to the issues that are being faced by such industries which are already prevailing in the market with special reference to Varanasi district.

Defining a cold pool-resolving scale for numerical simulations of convective self-organisation

2021 ◽  
Author(s):  
Romain Fiévet ◽  
Bettina Meyer ◽  
Jan Olaf Haerter
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Field Studies ◽  
Cold Pool ◽  
Small Scale ◽  
Convective Systems ◽  
Mesoscale Convective ◽  
Gust Fronts ◽  
Self Organisation ◽  
The Impact

&lt;p&gt;Spontaneous aggregation of clouds is a puzzling phenomenon observed in field studies [Holloway et al. (2017)] and idealized simulations alike [Held et al. (1993), Bretherton et al. (2005)]. With its relevance to climate sensitivity and extreme events, aggregation continues to be heavily studied, [Wing et al., 2017 for a review], with radiative-convective feedbacks emerging as main drivers of simulated convective self-aggregation (CSA) [Mueller &amp; Bony (2015)].&lt;/p&gt;&lt;p&gt;In state-of-the art cloud-resolving models, CSA finds itself consistently hampered by finer horizontal resolutions [Muller &amp; Held (2012), Yanase et al. (2020)]. This feature was ascribed to the effect of cold pool (CP) gust fronts in opposing the positive moisture feedback underlying CSA [Jeevanjee &amp; Romps (2013)]. In contrast, recent numerical experiments [Haerter et al. (2020)] with diurnally oscillating surface temperature highlights an orthogonal effect: stronger CPs, driven by small-scale density gradients, promote cloud field self-organization into mesoscale convective systems (MCS). Interestingly, this upscale growth, which we here term diurnal self-organisation (DSO), differs from classical CSA as it is driven by CPs rather than large-scale radiative imbalances. In stark contrast to CSA, strengthening CPs promotes this organization effect.&lt;/p&gt;&lt;p&gt;Hence, numerical simulations of CSA and DSO should go beyond the typical cloud-resolving paradigm and achieve cold pool-resolving capabilities. The current study systematically examines the impact of model resolution on CP effects. First, numerical convergence is probed in a 12km x 20km laterally periodic domain where a single CP propagates and self-collides at the domain's edges. As the spatial resolution is stepwise increased from 250 to 25m, it is shown that the initially coarsely resolved density current dissipates and collision and updraft effects are weak. As finer resolution is approached, we identify a cold pool resolving resolution D, which is deemed satisfactory for propagation and collision properties. Second, convergence for a (250km)2 domain under a diurnal radiative cycle is assessed at various spatial resolutions, including the scale D. This mesoscale configuration allows us to quantify the impact of resolution of cold pool dynamics on DSO.&lt;/p&gt;&lt;p&gt;Together, this work systematically lays out the numerical requirements to study mesoscale clustering by means of explicit numerical simulations.&lt;/p&gt;

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