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  1. Book ; Online ; Thesis: High Performance Computing Based Methods for Simulation and Optimisation of Flow Problems

    Bockelmann, Hendryk

    2010  

    Author's details von Hendryk Bockelmann
    Language English
    Size Online-Ressource
    Document type Book ; Online ; Thesis
    Thesis / German Habilitation thesis KIT, Diss.--Karlsruhe, 2010
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  2. Book ; Online: Concurrent calculation of radiative transfer in the atmospheric simulation in ECHAM-6.3.05p2

    Heidari, Mohammad Reza / Song, Zhaoyang / Degregori, Enrico / Behrens, Jörg / Bockelmann, Hendryk

    eISSN: 1991-9603

    2021  

    Abstract: The scalability of the atmospheric model ECHAM6 at low resolution, as used in palaeoclimate simulations, suffers from the limited number of grid points. As a consequence, the potential of current high-performance computing architectures cannot be used at ...

    Abstract The scalability of the atmospheric model ECHAM6 at low resolution, as used in palaeoclimate simulations, suffers from the limited number of grid points. As a consequence, the potential of current high-performance computing architectures cannot be used at full scale for such experiments, particularly within the available domain decomposition approach. Radiation calculations are a relatively expensive part of the atmospheric simulations, taking up to approximately 50 % or more of the total runtime. This current level of cost is achieved by calculating the radiative transfer only once in every 2 h of simulation. In response, we propose extending the available concurrency within the model further by running the radiation component in parallel with other atmospheric processes to improve scalability and performance. This paper introduces the concurrent radiation scheme in ECHAM6 and presents a thorough analysis of its impact on the performance of the model. It also evaluates the scientific results from such simulations. Our experiments show that ECHAM6 can achieve a speedup of over 1.9 × using the concurrent radiation scheme. By performing a suite of stand-alone atmospheric experiments, we evaluate the influence of the concurrent radiation scheme on the scientific results. The simulated mean climate and internal climate variability by the concurrent radiation generally agree well with the classical radiation scheme, with minor improvements in the mean atmospheric circulation in the Southern Hemisphere and the atmospheric teleconnection to the Southern Annular Mode. This empirical study serves as a successful example that can stimulate research on other concurrent components in atmospheric modelling whenever scalability becomes challenging.
    Subject code 551
    Language English
    Publishing date 2021-12-06
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

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  3. Article ; Online: Concurrent calculation of radiative transfer in the atmospheric simulation in ECHAM-6.3.05p2

    Heidari, Mohammad Reza / Song, Zhaoyang / Degregori, Enrico / Behrens, Jörg / Bockelmann, Hendryk

    2021  

    Abstract: The scalability of the atmospheric model ECHAM6 at low resolution, as used in palaeoclimate simulations, suffers from the limited number of grid points. As a consequence, the potential of current high-performance computing architectures cannot be used at ...

    Abstract The scalability of the atmospheric model ECHAM6 at low resolution, as used in palaeoclimate simulations, suffers from the limited number of grid points. As a consequence, the potential of current high-performance computing architectures cannot be used at full scale for such experiments, particularly within the available domain decomposition approach. Radiation calculations are a relatively expensive part of the atmospheric simulations, taking up to approximately 50 % or more of the total runtime. This current level of cost is achieved by calculating the radiative transfer only once in every 2 h of simulation. In response, we propose extending the available concurrency within the model further by running the radiation component in parallel with other atmospheric processes to improve scalability and performance. This paper introduces the concurrent radiation scheme in ECHAM6 and presents a thorough analysis of its impact on the performance of the model. It also evaluates the scientific results from such simulations. Our experiments show that ECHAM6 can achieve a speedup of over 1.9× using the concurrent radiation scheme. By performing a suite of stand-alone atmospheric experiments, we evaluate the influence of the concurrent radiation scheme on the scientific results. The simulated mean climate and internal climate variability by the concurrent radiation generally agree well with the classical radiation scheme, with minor improvements in the mean atmospheric circulation in the Southern Hemisphere and the atmospheric teleconnection to the Southern Annular Mode. This empirical study serves as a successful example that can stimulate research on other concurrent components in atmospheric modelling whenever scalability becomes challenging.
    Subject code 551
    Language English
    Publishing date 2021-12-06
    Publisher Copernicus Publications (EGU)
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

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  4. Article ; Online: Optimization of an electrokinetic mixer for microfluidic applications.

    Bockelmann, Hendryk / Heuveline, Vincent / Barz, Dominik P J

    Biomicrofluidics

    2012  Volume 6, Issue 2, Page(s) 24123–2412318

    Abstract: This work is concerned with the investigation of the concentration fields in an electrokinetic micromixer and its optimization in order to achieve high mixing rates. The mixing concept is based on the combination of an alternating electrical excitation ... ...

    Abstract This work is concerned with the investigation of the concentration fields in an electrokinetic micromixer and its optimization in order to achieve high mixing rates. The mixing concept is based on the combination of an alternating electrical excitation applied to a pressure-driven base flow in a meandering microchannel geometry. The electrical excitation induces a secondary electrokinetic velocity component, which results in a complex flow field within the meander bends. A mathematical model describing the physicochemical phenomena present within the micromixer is implemented in an in-house finite-element-method code. We first perform simulations comparable to experiments concerned with the investigation of the flow field in the bends. The comparison of the complex flow topology found in simulation and experiment reveals excellent agreement. Hence, the validated model and numerical schemes are employed for a numerical optimization of the micromixer performance. In detail, we optimize the secondary electrokinetic flow by finding the best electrical excitation parameters, i.e., frequency and amplitude, for a given waveform. Two optimized electrical excitations featuring a discrete and a continuous waveform are discussed with respect to characteristic time scales of our mixing problem. The results demonstrate that the micromixer is able to achieve high mixing degrees very rapidly.
    Language English
    Publishing date 2012-05-24
    Publishing country United States
    Document type Journal Article
    ISSN 1932-1058
    ISSN (online) 1932-1058
    DOI 10.1063/1.4722000
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Book ; Online: ICON-Sapphire

    Hohenegger, Cathy / Korn, Peter / Linardakis, Leonidas / Redler, René / Schnur, Reiner / Adamidis, Panagiotis / Bao, Jiawei / Bastin, Swantje / Behravesh, Milad / Bergemann, Martin / Biercamp, Joachim / Bockelmann, Hendryk / Brokopf, Renate / Brüggemann, Nils / Casaroli, Lucas / Chegini, Fatemeh / Datseris, George / Esch, Monika / George, Geet /
    Giorgetta, Marco / Gutjahr, Oliver / Haak, Helmuth / Hanke, Moritz / Ilyina, Tatiana / Jahns, Thomas / Jungclaus, Johann / Kern, Marcel / Klocke, Daniel / Kluft, Lukas / Kölling, Tobias / Kornblueh, Luis / Kosukhin, Sergey / Kroll, Clarissa / Lee, Junhong / Mauritsen, Thorsten / Mehlmann, Carolin / Mieslinger, Theresa / Naumann, Ann Kristin / Paccini, Laura / Peinado, Angel / Praturi, Divya Sri / Putrasahan, Dian / Rast, Sebastian / Riddick, Thomas / Roeber, Niklas / Schmidt, Hauke / Schulzweida, Uwe / Schütte, Florian / Segura, Hans / Shevchenko, Radomyra

    eISSN: 1991-9603

    simulating the components of the Earth system and their interactions at kilometer and subkilometer scales

    2023  

    Abstract: State-of-the-art Earth system models typically employ grid spacings of O(100 km), which is too coarse to explicitly resolve main drivers of the flow of energy and matter across the Earth system. In this paper, we present the new ICON-Sapphire model ... ...

    Abstract State-of-the-art Earth system models typically employ grid spacings of O(100 km), which is too coarse to explicitly resolve main drivers of the flow of energy and matter across the Earth system. In this paper, we present the new ICON-Sapphire model configuration, which targets a representation of the components of the Earth system and their interactions with a grid spacing of 10 km and finer. Through the use of selected simulation examples, we demonstrate that ICON-Sapphire can (i) be run coupled globally on seasonal timescales with a grid spacing of 5 km, on monthly timescales with a grid spacing of 2.5 km, and on daily timescales with a grid spacing of 1.25 km; (ii) resolve large eddies in the atmosphere using hectometer grid spacings on limited-area domains in atmosphere-only simulations; (iii) resolve submesoscale ocean eddies by using a global uniform grid of 1.25 km or a telescoping grid with the finest grid spacing at 530 m, the latter coupled to a uniform atmosphere; and (iv) simulate biogeochemistry in an ocean-only simulation integrated for 4 years at 10 km. Comparison of basic features of the climate system to observations reveals no obvious pitfalls, even though some observed aspects remain difficult to capture. The throughput of the coupled 5 km global simulation is 126 simulated days per day employing 21 % of the latest machine of the German Climate Computing Center. Extrapolating from these results, multi-decadal global simulations including interactive carbon are now possible, and short global simulations resolving large eddies in the atmosphere and submesoscale eddies in the ocean are within reach.
    Subject code 551
    Language English
    Publishing date 2023-01-31
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

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  6. Article ; Online: ICON-Sapphire

    Hohenegger, Cathy / Korn, Peter / Linardakis, Leonidas / Redler, René / Schnur, Reiner / Adamidis, Panagiotis / Bao, Jiawei / Bastin, Swantje / Behravesh, Milad / Bergemann, Martin / Biercamp, Joachim / Bockelmann, Hendryk / Brokopf, Renate / Brüggemann, Nils / Casaroli, Lucas / Chegini, Fatemeh / Datseris, George / Esch, Monika / George, Geet /
    Giorgetta, Marco / Gutjahr, Oliver / Haak, Helmuth / Hanke, Moritz / Ilyina, Tatiana / Jahns, Thomas / Jungclaus, Johann / Kern, Marcel / Klocke, Daniel / Kluft, Lukas / Kölling, Tobias / Kornblueh, Luis / Kosukhin, Sergey / Kroll, Clarissa / Lee, Junhong / Mauritsen, Thorsten / Mehlmann, Carolin / Mieslinger, Theresa / Naumann, Ann Kristin / Paccini, Laura / Peinado, Angel / Praturi, Divya Sri / Putrasahan, Dian / Rast, Sebastian / Riddick, Thomas / Roeber, Niklas / Schmidt, Hauke / Schulzweida, Uwe / Schütte, Florian / Segura, Hans / Shevchenko, Radomyra / Singh, Vikram / Specht, Mia / Stephan, Claudia Christine / von Storch, Jin-Song / Vogel, Raphaela / Wengel, Christian / Winkler, Marius / Ziemen, Florian / Marotzke, Jochem / Stevens, Bjorn

    simulating the components of the Earth system and their interactions at kilometer and subkilometer scales

    2023  

    Abstract: State-of-the-art Earth system models typically employ grid spacings of O(100 km), which is too coarse to explicitly resolve main drivers of the flow of energy and matter across the Earth system. In this paper, we present the new ICON-Sapphire model ... ...

    Abstract State-of-the-art Earth system models typically employ grid spacings of O(100 km), which is too coarse to explicitly resolve main drivers of the flow of energy and matter across the Earth system. In this paper, we present the new ICON-Sapphire model configuration, which targets a representation of the components of the Earth system and their interactions with a grid spacing of 10 km and finer. Through the use of selected simulation examples, we demonstrate that ICON-Sapphire can (i) be run coupled globally on seasonal timescales with a grid spacing of 5 km, on monthly timescales with a grid spacing of 2.5 km, and on daily timescales with a grid spacing of 1.25 km; (ii) resolve large eddies in the atmosphere using hectometer grid spacings on limited-area domains in atmosphere-only simulations; (iii) resolve submesoscale ocean eddies by using a global uniform grid of 1.25 km or a telescoping grid with the finest grid spacing at 530 m, the latter coupled to a uniform atmosphere; and (iv) simulate biogeochemistry in an ocean-only simulation integrated for 4 years at 10 km. Comparison of basic features of the climate system to observations reveals no obvious pitfalls, even though some observed aspects remain difficult to capture. The throughput of the coupled 5 km global simulation is 126 simulated days per day employing 21 % of the latest machine of the German Climate Computing Center. Extrapolating from these results, multi-decadal global simulations including interactive carbon are now possible, and short global simulations resolving large eddies in the atmosphere and submesoscale eddies in the ocean are within reach.
    Subject code 551
    Language English
    Publishing date 2023-01-31
    Publisher Copernicus Publications (EGU)
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

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    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Book ; Online: ICON-Sapphire

    Hohenegger, Cathy / Korn, Peter / Linardakis, Leonidas / Redler, René / Schnur, Reiner / Adamidis, Panagiotis / Bao, Jiawei / Bastin, Swantje / Behravesh, Milad / Bergemann, Martin / Biercamp, Joachim / Bockelmann, Hendryk / Brokopf, Renate / Brüggemann, Nils / Casaroli, Lucas / Chegini, Fatemeh / Datseris, George / Esch, Monika / George, Geet /
    Giorgetta, Marco / Gutjahr, Oliver / Haak, Helmuth / Hanke, Moritz / Ilyina, Tatiana / Jahns, Thomas / Jungclaus, Johann / Kern, Marcel / Klocke, Daniel / Kluft, Lukas / Kölling, Tobias / Kornblueh, Luis / Kosukhin, Sergey / Kroll, Clarissa / Lee, Junhong / Mauritsen, Thorsten / Mehlmann, Carolin / Mieslinger, Theresa / Naumann, Ann Kristin / Paccini, Laura / Peinado, Angel / Praturi, Divya Sri / Putrasahan, Dian / Rast, Sebastian / Riddick, Thomas / Roeber, Niklas / Schmidt, Hauke / Schulzweida, Uwe / Schütte, Florian / Segura, Hans / Shevchenko, Radomyra

    eISSN: 1991-9603

    simulating the components of the Earth System and their interactions at kilometer and subkilometer scales

    2022  

    Abstract: State-of-the-art Earth System models typically employ grid spacings of O(100 km), too coarse to explicitly resolve main drivers of the flow of energy and matter across the Earth System. In this paper, we present the new ICON-Sapphire model configuration, ...

    Abstract State-of-the-art Earth System models typically employ grid spacings of O(100 km), too coarse to explicitly resolve main drivers of the flow of energy and matter across the Earth System. In this paper, we present the new ICON-Sapphire model configuration, which targets a representation of the components of the Earth System and their interactions with a grid spacing of 10 km and finer. Through the use of selected simulation examples, we demonstrate that ICON-Sapphire can already now (i) be run coupled globally on seasonal time scales with a grid spacing of 5 km and on monthly time scales with a grid spacing of 2.5 km, (ii) resolve large eddies in the atmosphere using hectometer grid spacings on limited-area domains in atmosphere-only simulations, (iii) resolve submesoscale ocean eddies by using a global uniform grid of 1.25 km or a telescoping grid with a finest grid spacing of 530 m, the latter coupled to a uniform atmosphere and (iv) simulate biogeochemistry in an ocean-only simulation integrated for 4 years at 10 km. Comparison to observations of these various configurations reveals no obvious pitfall. The throughput of the coupled 5-km global simulation is 126 simulated days per day employing 21 % of the latest machine of the German Climate Computing Center. Extrapolating from these results, multi-decadal global simulations including interactive carbon are now possible and short global simulations resolving large eddies in the atmosphere and submesoscale eddies in the ocean are within reach.
    Subject code 551
    Language English
    Publishing date 2022-07-21
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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