Relevant bibliographies by topics / SPH

Academic literature on the topic 'SPH'

Author: Grafiati
Published: 4 June 2021
Last updated: 18 May 2024

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Journal articles on the topic "SPH"

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Avesani, Diego, Michael Dumbser, Renato Vacondio, and Maurizio Righetti. "An alternative SPH formulation: ADER-WENO-SPH." Computer Methods in Applied Mechanics and Engineering 382 (August 2021): 113871. http://dx.doi.org/10.1016/j.cma.2021.113871.

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Chow, E., and J. J. Monaghan. "Ultrarelativistic SPH." Journal of Computational Physics 134, no. 2 (July 1997): 296–305. http://dx.doi.org/10.1006/jcph.1997.5708.

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Krautscheid, Ulrike, Somanath Dev, Harald Krautscheid, Partha P. Paul, Scott R. Wilson, and Thomas B. Rauchfuss. "N-Methylimidazole Mediated Chemistry of Transition Metal Phenylthiolates. The Isolation of the Perthiolate Salts [M(N-MeIm)6](S2Ph)2." Zeitschrift für Naturforschung B 48, no. 5 (May 1, 1993): 653–58. http://dx.doi.org/10.1515/znb-1993-0515.

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Salts of the composition [M(N-MeIm)6](SPh)2 (M = Mn, Ni; N-MeIm = N-methylimidazole) were prepared by dissolution of the metal powders with N-MeIm solutions of Ph2S2. X-ray crystallographic examination established that these salts indeed feature uncoordinated PhS-. The salts [M(N-McIm)6](SPh)2 (M = Mn, Ni) react with S8 to give [M(N-MeIm)6]S8 via the intermediacy of the perthiolate salts [M(N-MeIm)6](S2Ph)2.
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Frei, Anne C., YiHe Guo, Deron W. Jones, Kirkwood A. Pritchard, Karen A. Fagan, Neil Hogg, and Nancy J. Wandersee. "Vascular dysfunction in a murine model of severe hemolysis." Blood 112, no. 2 (July 15, 2008): 398–405. http://dx.doi.org/10.1182/blood-2007-12-126714.

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Abstract Spectrin is the backbone of the erythroid cytoskeleton; sph/sph mice have severe hereditary spherocytosis (HS) because of a mutation in the murine erythroid α-spectrin gene. sph/sph mice have a high incidence of thrombosis and infarction in multiple tissues, suggesting significant vascular dysfunction. In the current study, we provide evidence for both pulmonary and systemic vascular dysfunction in sph/sph mice. We found increased levels of soluble cell adhesion molecules in sph/sph mice, suggesting activation of the vascular endothelium. We hypothesized that plasma hemoglobin released by intravascular hemolysis initiates endothelial injury through nitric oxide (NO) scavenging and oxidative damage. Likewise, electron paramagnetic resonance spectroscopy showed that plasma hemoglobin is much greater in sph/sph mice. Moreover, plasma from sph/sph mice had significantly higher oxidative potential. Finally, xanthine oxidase, a potent superoxide generator, is decreased in subpopulations of liver hepatocytes and increased on liver endothelium in sph/sph mice. These results indicate that vasoregulation is abnormal, and NO-based vasoregulatory mechanisms particularly impaired, in sph/sph mice. Together, these data indicate that sph/sph mice with severe HS have increased plasma hemoglobin and NO scavenging capacity, likely contributing to aberrant vasoregulation and initiating oxidative damage.
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Olkowski, Brian F., and Angela M. Stolfi. "Safe Patient Handling Perceptions and Practices: A Survey of Acute Care Physical Therapists." Physical Therapy 94, no. 5 (May 1, 2014): 682–95. http://dx.doi.org/10.2522/ptj.20120539.

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BackgroundAcute care physical therapists are at risk for developing work-related musculoskeletal disorders (WMSDs) due to manual patient handling. Safe patient handling (SPH) reduces WMSDs caused by manual handling.ObjectiveThe purpose of this study was to describe the patient handling practices of acute care physical therapists and their perceptions regarding SPH. Additionally, this study determined whether an SPH program influences the patient handling practices and perceptions regarding SPH of acute care physical therapists.MethodsSubscribers to the electronic discussion board of American Physical Therapy Association's Acute Care Section were invited to complete a survey questionnaire.ResultsThe majority of respondents used SPH equipment and practices (91.1%), were confident using SPH equipment and practices (93.8%), agreed that evidence supports the use of SPH equipment and practices (87.0%), and reported the use of SPH equipment and practices is feasible (92.2%). Respondents at a facility with an SPH program were more likely to use SPH equipment and practices, have received training in the use of SPH equipment and practices, agree that the use of SPH equipment and practices is feasible, and feel confident using SPH equipment and practices.LimitationsThe study might not reflect the perceptions and practices of the population of acute care physical therapists.ConclusionAcute care physical therapists are trained to use SPH equipment and practices, use SPH equipment and practices, and have positive perceptions regarding SPH. Acute care physical therapists in a facility with an SPH program are more likely to use SPH equipment and practices, receive training in SPH equipment and practices, and have positive perceptions regarding SPH. Quasi-regulatory organizations should incorporate SPH programs into their evaluative standards.
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Hisano, Nobuo, Yutaka Yatomi, Kaneo Satoh, Shigeo Akimoto, Masako Mitsumata, Masayuki A. Fujino, and Yukio Ozaki. "Induction and Suppression of Endothelial Cell Apoptosis by Sphingolipids: A Possible In Vitro Model for Cell-Cell Interactions Between Platelets and Endothelial Cells." Blood 93, no. 12 (June 15, 1999): 4293–99. http://dx.doi.org/10.1182/blood.v93.12.4293.

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Abstract Because sphingosine (Sph) is actively incorporated into platelets and rapidly converted to sphingosine 1-phosphate (Sph-1-P), which is then released extracellularly, it is important to study the effects of Sph and Sph-1-P on endothelial cells from the viewpoint of platelet-endothelial cell interaction. In this study, we found that Sph, as well as ceramide, induces apoptosis in human umbilical vein endothelial cells (HUVECs). In contrast, Sph-1-P acts as a HUVEC survival factor; this bioactive lipid was shown to protect HUVECs from apoptosis induced by the withdrawal of growth factors and to stimulate HUVEC DNA synthesis. In metabolic studies, [3H]Sph, incorporated into HUVECs, was converted to [3H]Cer and further to [3H]sphingomyelin in a time-dependent manner, whereas [3H]Sph-1-P formation from [3H]Sph was weak and transient. These findings in HUVECs are very different from those of platelets, which possess a highly active Sph kinase but lack Sph-1-P lyase. As a result, platelets abundantly store Sph-1-P, whereas HUVECs contain much less Sph-1-P. Finally, HUVECs, in contrast to platelets, failed to release Sph-1-P extracellularly, indicating that HUVECs themselves are not able to supply the survival factor Sph-1-P, but receive it from activated platelets. Our results suggest that platelets may maintain the integrity of endothelial cells by incorporating Sph and releasing Sph-1-P.
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Hisano, Nobuo, Yutaka Yatomi, Kaneo Satoh, Shigeo Akimoto, Masako Mitsumata, Masayuki A. Fujino, and Yukio Ozaki. "Induction and Suppression of Endothelial Cell Apoptosis by Sphingolipids: A Possible In Vitro Model for Cell-Cell Interactions Between Platelets and Endothelial Cells." Blood 93, no. 12 (June 15, 1999): 4293–99. http://dx.doi.org/10.1182/blood.v93.12.4293.412k26_4293_4299.

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Because sphingosine (Sph) is actively incorporated into platelets and rapidly converted to sphingosine 1-phosphate (Sph-1-P), which is then released extracellularly, it is important to study the effects of Sph and Sph-1-P on endothelial cells from the viewpoint of platelet-endothelial cell interaction. In this study, we found that Sph, as well as ceramide, induces apoptosis in human umbilical vein endothelial cells (HUVECs). In contrast, Sph-1-P acts as a HUVEC survival factor; this bioactive lipid was shown to protect HUVECs from apoptosis induced by the withdrawal of growth factors and to stimulate HUVEC DNA synthesis. In metabolic studies, [3H]Sph, incorporated into HUVECs, was converted to [3H]Cer and further to [3H]sphingomyelin in a time-dependent manner, whereas [3H]Sph-1-P formation from [3H]Sph was weak and transient. These findings in HUVECs are very different from those of platelets, which possess a highly active Sph kinase but lack Sph-1-P lyase. As a result, platelets abundantly store Sph-1-P, whereas HUVECs contain much less Sph-1-P. Finally, HUVECs, in contrast to platelets, failed to release Sph-1-P extracellularly, indicating that HUVECs themselves are not able to supply the survival factor Sph-1-P, but receive it from activated platelets. Our results suggest that platelets may maintain the integrity of endothelial cells by incorporating Sph and releasing Sph-1-P.
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Wandersee, Nancy J., John C. Lee, Tamma M. Kaysser, Roderick T. Bronson, and Jane E. Barker. "Hematopoietic Cells From -Spectrin–Deficient Mice Are Sufficient to Induce Thrombotic Events in Hematopoietically Ablated Recipients." Blood 92, no. 12 (December 15, 1998): 4856–63. http://dx.doi.org/10.1182/blood.v92.12.4856.

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Abstract Thrombotic events are life-threatening complications of human hemolytic anemias such as paroxysmal nocturnal hemoglobinuria, sickle cell disease, and thalassemia. It is not clear whether these events are solely influenced by aberrant hematopoietic cells or also involve aberrant nonhematopoietic cells. Spherocytosis mutant (Spna1sph/Spna1sph; for simplicity referred to as sph/sph) mice develop a severe hemolytic anemia postnatally due to deficiencies in -spectrin in erythroid and other as yet incompletely defined nonerythroid tissues. Thrombotic lesions occur in all adult sph/sph mice, thus providing a hematopoietically stressed model in which to assess putative causes of thrombus formation. To determine whether hematopoietic cells fromsph/sph mice are sufficient to initiate thrombi, bone marrow from sph/sph or +/+ mice was transplanted into mice with no hemolytic anemia. One set of recipients was lethally irradiated; the other set was genetically stem cell deficient. All mice implanted withsph/sph marrow, but not +/+ marrow, developed severe anemia and histopathology typical of sph/sph mice. Histological analyses of marrow recipients showed that thrombi were present in the recipients of sph/sph marrow, but not +/+ marrow. The results indicate that the -spectrin–deficient hematopoietic cells of sph/sph mice are the primary causative agents of the thrombotic events.
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Wandersee, Nancy J., John C. Lee, Tamma M. Kaysser, Roderick T. Bronson, and Jane E. Barker. "Hematopoietic Cells From -Spectrin–Deficient Mice Are Sufficient to Induce Thrombotic Events in Hematopoietically Ablated Recipients." Blood 92, no. 12 (December 15, 1998): 4856–63. http://dx.doi.org/10.1182/blood.v92.12.4856.424k31_4856_4863.

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Thrombotic events are life-threatening complications of human hemolytic anemias such as paroxysmal nocturnal hemoglobinuria, sickle cell disease, and thalassemia. It is not clear whether these events are solely influenced by aberrant hematopoietic cells or also involve aberrant nonhematopoietic cells. Spherocytosis mutant (Spna1sph/Spna1sph; for simplicity referred to as sph/sph) mice develop a severe hemolytic anemia postnatally due to deficiencies in -spectrin in erythroid and other as yet incompletely defined nonerythroid tissues. Thrombotic lesions occur in all adult sph/sph mice, thus providing a hematopoietically stressed model in which to assess putative causes of thrombus formation. To determine whether hematopoietic cells fromsph/sph mice are sufficient to initiate thrombi, bone marrow from sph/sph or +/+ mice was transplanted into mice with no hemolytic anemia. One set of recipients was lethally irradiated; the other set was genetically stem cell deficient. All mice implanted withsph/sph marrow, but not +/+ marrow, developed severe anemia and histopathology typical of sph/sph mice. Histological analyses of marrow recipients showed that thrombi were present in the recipients of sph/sph marrow, but not +/+ marrow. The results indicate that the -spectrin–deficient hematopoietic cells of sph/sph mice are the primary causative agents of the thrombotic events.
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Schraufnagel, Anne C., Barb Piknova, Kirkwood A. Pritchard, Neil Hogg, and Nancy J. Wandersee. "Nitric Oxide Scavenging, Abnormal Vasoregulation and Oxidative Damage in sph/sph Mice with Severe Hereditary Spherocytosis: Possible Consequences of Red Blood Cell Hemolysis." Blood 106, no. 11 (November 16, 2005): 1660. http://dx.doi.org/10.1182/blood.v106.11.1660.1660.

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Abstract The membrane skeleton, a multiprotein complex located just beneath the plasma membrane, provides the red blood cell (RBC) with the mechanical strength and deformability required to withstand high shear forces generated in the microcapillaries. Spectrin, a tetramer composed of a- and b- subunits, is the backbone of the erythroid membrane skeleton. Previously, we have shown that sph/sph mice have severe hereditary spherocytosis (HS) due to a spontaneous single-base deletion in the murine erythroid a-spectrin gene, Spna1. HS mice have severe hemolytic anemia, compensatory reticulocytosis, altered RBC morphology and increased fragility. Vascular dysfunction in sph/sph mice likely plays an important role in the mechanism by which these mice develop a high incidence of cardiac thrombosis and stroke between 6 and 12 weeks of age. We hypothesize that serum free hemoglobin released from intravascular hemolysis of sph/sph RBCs and xanthine oxidase, released from ischemic tissues, impairs endothelial cell function by scavenging nitric oxide (NO) and increasing oxidative damage. To test this hypothesis, we used helium electroparamagnetic resonance (EPR), to quantify plasma free Hb and NO scavenging capacity in the plasma of the mice; immunohistochemistry to determine tissue and vascular levels of xanthine oxidase and 3-nitrotyrosine; and, facialis arteries to measure changes in acetylcholine, endothelium and eNOS-dependent vasodilation. By EPR we found that the plasma free Hb and NO scavenging capacity in the plasma of sph/sph mice is much greater than that of the normal +/+ mice. Immunohistochemistry (IHC) for XO and NTyr revealed XO staining was decreased in livers of sph/sph mice as compared to livers from normal +/+ mice. XO staining was increased in local patches on the endothelium of lungs isolated from sph/sph mice compared to lungs from +/+ mice. NTyr, a marker of peroxynitrite formation was also increased in a focal manner in lungs of sph/sph mice compared to lungs of +/+ mice. Acetylcholine-induced and eNOS-dependent vasodilation in sph/sph mice was significantly impaired compared to vasodilation in normal +/+ mice. Taken together these data suggest the hemoglobin removal system in sph/sph mice is saturated, leading to increased free Hb and nitric oxide scavenging. IHC studies reveal XO is released from liver in sph/sph mice and once released binds the endothelium of lung, quite distal from the original site of injury. Such changes likely contribute to marked increases in NTyr staining and impaired endothelium and eNOS-dependent vasodilation in facialis arteries isolated from sph/sph mice. Taken together, these data indicate that sph/sph mice with severe HS have increased plasma free Hb and NO scavenging capacity as well as increased release of xanthine oxidase and subsequent binding to vascular endothelial cells to locations that are distal the original site of injury. Such plasma and vascular changes in hemoglobin and oxidative enzymes likely play a critical role in the mechanisms contributing to aberrant vasoregulation and initiating the pathways of oxidative damage found in sph/sph mice.
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Dissertations / Theses on the topic "SPH"

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Akinci, Gizem [Verfasser], and Matthias [Akademischer Betreuer] Teschner. "Efficient surface reconstruction for SPH fluids = Effiziente Oberflächenrekonstruktion für SPH Flüssigkeiten." Freiburg : Universität, 2014. http://d-nb.info/1114829315/34.

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JESUS, E. M. "Operadores SPH sobre variedades." Universidade Federal do Espírito Santo, 2017. http://repositorio.ufes.br/handle/10/7408.

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Made available in DSpace on 2018-08-01T22:00:13Z (GMT). No. of bitstreams: 1 tese_10699_dissertacao.pdf: 17285608 bytes, checksum: 0575dea8caa70653dee0fde52d83496d (MD5) Previous issue date: 2017-02-20
Este projeto propõe uma extensão do método SPH (Smoothed Particle Hydrodynamics) [1] para variedade diferenciáveis. Inicialmente desenvolvido no Rn, o método SPH baseia-se no conceito de representação integral que não é estendido de forma natural para variedade. No entanto, este conceito pode ser aplicado ao espaço tangente da variedade. Sendo assim, impondo algumas condições a variedade, o método SPH poderá ser aplicado à pontos projetados no espaço tangente de cada partícula [2]. Esta abordagem resulta numa boa aproximação para os operadores diferenciais sobre a variedade, sendo assim considerada uma generalização consistente do método. Estes operadores generalizados serão utilizados na Decomposição de Helmhotz-Hodge e análise de campos vetoriais [3], simulação de fluidos incompressíveis, resolução de equações clássicas como a equação da onda, equação do calor, dentre outras, sobre variedades. Bibliografia: 1) Liu, Gui-Rong e Liu, M.B. "Smoothed Particle Hydrodynamics: A Meshfree Particle Method". World Scientific, 2003 2) Petronetto, Fabiano, et al. "Mesh-Free Discrete Laplace-Beltrami Operator". Computer Graphics Forum, 2013. 3) Petronetto, Fabiano, et al. "Meshless helmholtz-hodge decomposition". IEEE transactions on visualization and computer graphics, 2010. 4) Mercier, Olivier, et. al. "Surface turbulence for particle-based liquid simulations". ACM Transactions on Graphics (TOG), 2015.
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SILVA, César Leonardo Barbosa da. "Condições de contorno em SPH." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/23924.

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CAPES
Nesta dissertação será apresentado o método SPH - Smoothed Particle Hydrodynamics, - em português, Hidrodinâmica da Partícula Suavizada, um método sem malhas baseado em distribuições de partículas. O método foi inicialmente desenvolvido, em 1988, para simulações de sistemas astronômicos, onde as grandezas envolvidas sofrem variações bruscas e e grandes. Seus criadores desejavam um método que fosse fácil de se trabalhar e que, em contrapartida, fornecesse uma precisão coerente. O SPH é muito utilizado em aplicações em sistemas fluidos ou granulares, mas nada impede, e muito tem sido feito, de se aplicar a sistemas sólidos e de alta viscosidade. O SPH, em comparação com, por exemplo, Método do Elemento Finito, apresenta a grande vantagem de não sofrer com as grandes deformaç oes, em virtude de sua natureza particular. Neste trabalho estabeleceremos os fundamentos matemáticos que são a essência método. Serão exibidas algumas de suas aplicações e discutidas as principais condições de contorno utilizadas pelos pesquisadores da área, bem como proposta uma condição funcional que será simulada. Por fim, os resultados serão comparados com alguns outros trabalhos desenvolvidos por outros pesquisadores na área.
The SPH- Smoothed Particle Hydrodynamics-, in portuguese, Hidrodinâmica da Partícula Suavizada, will be presented. It is a meshless method based on particles distributions. The method was initially developed in 1988 for simulations of astronomical systems, where the quantities involved suffer abrupt and large variations. Its creators wanted a method that was easy to work with and, on the counterpart, would give a coherent precision. The SPH is mainly applied to fluid or granular systems but can be applied to solid or high viscous systems. The SPH method in comparison, for example, to Finite Element Method, shows a great advantage once do not have the problem when treating large deformations, in virtue of his particular nature. In this dissertation will be presented the mathematical foundations that are the essence of the method. It will be exhibited some of their applications and some of the major boundary conditions used by the researchers in the subject. It will be also proposed a functional condition to be simulated. Finely, the results will be compared to some other simulations developed by researchers in this area.
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Escartín, Vigo José Antonio. "ISFAA : Implicit SPH for astrophysical apllications." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/384002.

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Computational simulation is one of the basic techniques of modern Astrophysics. The long-term time astrophysical processes cannot be treated with explicit approaches because that they are limited, in their maximum time step, by the restriction known as Courant-Friedrichs-Lewy Condition. In order to use implicit approaches a system of coupled algebraic equations needs to be solved. It is composed by all the equations of each one of the discrete points of the model and the usual solution comes through a Newton-Raphson scheme. The computational cost substantially increases with the number of unknowns of the model. In implicit schemes the properties of the current time step depends on the values of the unknown variables at that time step, so everything has to be calculated simultaneously. The consequence is that all equations should be jointly solved inverting of a huge sparse matrix (it is a squared n*v matrix, being n the number of particles and v the number of independent variables of the system). Due to this restriction, historically the implicit hydrodynamics had been only applied to one-dimensional systems. It would be very interesting to build an Implicit hydrocode taking advantage of the so called Smoothed Particle Hydrodynamics or SPH. This technique has been being applied successfully in astrophysics and cosmology and fluid physics. SPH integrates the dynamic fluid equations in each point of the Lagragian formalism (named particles because they have an associated mass) calculating speed, position, density and pressure as interpolations from neighbour particles. Unlike Eulerian methods the Lagragian approach does not need from a rectangular grid covering the integration domain. Therefore storage and computing time is not wasted in void regions. Fluids are decomposed in a set of particles where the numerical treatment of the three-dimensional movement derived from pressure and auto-gravity is easier. The goal of this thesis is to describe the main features and the implementation of a new SPH code which uses implicit approach, called ISFAA (Implicit SPH for Astrophysical Applications). This code enlarges the previous work from "An Implicit Smooth Particle hydrodynamic Code", Knapp C. (2000) and recent developments of the SPH scheme (based on the variation principle), artificial viscosity, gravity and thermal conductivity. Because of the huge effort which has to be invested to build and validate the new SPH code, it is pretended that in the future its use can be extended to a large number of scenarios. With this end a modular design has been implemented that allows to separate the code general treatment, the particular implementation of the basic evolutionary equations and the physical properties (equation of state, artificial viscosity, etc.). Furthermore, to find the solution of the equations' system, the library of parallel algorithms PARDISO, embodied in the library Intel MKL, has been used. Future improvements in these libraries will have a positive impact on the new code. To validate the code and check each one of the physical ingredients, a set of basic tests (point-like explosion, The wall heating shock, Rayleigh-Taylor instabilities, Free-Fall collapse, etc) were run and analyzed as well as several tests incorporating gravity (Toy Star, stability of a solar mass star and a White Dwarf). And finally, we show the evolution of a single quasi-static system. To handle with these scenarios we have built a slightly different implicit scheme, were velocities are not explicitly included in the equations of movement. The main aim of this tests is to demonstrate that an implicit quasi-hydrostatic scheme is able to work with time-steps many orders of magnitude large (10^4) than the characteristic current Courant time.
La simulación mediante ordenador es una de las herramientas básicas de la Astrofísica moderna. Los procesos de gran escala temporal son imposibles de tratar con enfoques explícitos ya que estos se encuentran limitados, en su paso de tiempo máximo, por la restricción conocida como condición de Courant-Friedrichs-Lewy. Para utilizar los enfoques implícitos se genera un sistema de ecuaciones algebraicas acopladas, habitualmente resuelto con un esquema de Newton-Raphson y compuesto por todas las ecuaciones de cada uno de los puntos de resolución del modelo. El coste computacional de resolución aumenta sustancialmente con el número de incógnitas que han de determinarse a cada paso de tiempo. Las propiedades del siguiente paso de tiempo dependen de los valores de las variables desconocidas en dicho paso de tiempo y por tanto todas han de ser calculadas simultáneamente. La consecuencia es que todo el sistema de ecuaciones se ha de resolver conjuntamente realizando la inversión de una matriz dispersa enorme (la matriz es cuadrada y tiene un tamaño de n*v, siendo n el numero de partículas y v el número de variables independientes del sistema). Debido a esta restricción, la hidrodinámica implícita históricamente ha sido aplicada a sistemas en una sola dimensión. Para su implementación multidimensional sería interesante utilizar un enfoque lagrangiano como el suavizado de partículas hidrodinámicas denominado "Smooth Particle Hydrodynamics" ó SPH. La técnica se viene aplicando con éxito al campo de la astrofísica, la cosmología y diferentes problemas de la física de fluidos. El SPH integra las ecuaciones de la dinámica de fluidos en cada punto del formalismo lagrangiano (denominado partícula por tener una masa asociada) calculando velocidad, posición, densidad y presión como una interpolación de los valores de las partículas vecinas. Los métodos lagrangianos, a diferencia de los eulerianos, no necesitan de una malla regular que cubra la totalidad del espacio de integración, por tanto, la memoria y el tiempo de cálculo no se desperdician en la resolución de espacios vacíos. Los fluidos se descomponen en un conjunto de partículas donde podemos tratar numéricamente de forma más sencilla el movimiento en tres dimensiones derivado de las fuerzas de presión y auto-gravedad. El objetivo de esta tesis es detallar las principales características y la implementación de un nuevo código SPH, con un enfoque implícito, al que hemos denominado ISFAA (Implicit SPH for Astrophysical Applications). Este código amplia el trabajo previo de Knapp. C., 2000 e incluye el esquema físico más actual del SPH (basado en el principio variacional), viscosidad artificial, gravedad y conductividad térmica. Dado el enorme esfuerzo que supone construir y validar un nuevo código SPH, se pretende que en el futuro su utilidad se extienda al mayor número posible de escenarios. Con este fin se ha optado por un diseño modular que separe el tratamiento general del código de la implementación concreta de ecuaciones evolutivas básicas y de las propiedades del material (ecuación de estado, viscosidad artificial, etc.). Además, para la resolución del sistema de ecuaciones se utiliza la biblioteca de algoritmos paralelos PARDISO, que incorpora la librería Intel MKL y que en el futuro tendrá mejoras que impactarán positivamente en el código. Para comprobar la corrección del código y probar cada uno de los ingredientes físicos, se especifican una serie de test básicos (Explosión puntual, The wall heating shock, inestabilidades de Rayleigh-Taylor, caída libre, etc.) y una serie de test con gravedad (Toy Star, estabilización de una estrella de masa solar y una enana blanca). Por último se muestra la evolución de un sistema cuasiestático, en el que las velocidades no se encuentran explícitamente en el modelo. Este test está orientado a demostrar que el código implícito podría aplicarse con éxito en estas situaciones, consiguiendo simular el sistema en largos intervalos temporales.
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Schindler, Benjamin. "Visualization of vortices in SPH data." Zurich : ETH, Eidgenössische Technische Hochschule Zürich, Department of Computer Science, Computer Graphics Laboratory, 2009. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=460.

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Chow, Alex. "Incompressible SPH (ISPH) on the GPU." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/incompressible-sph-isph-on-the-gpu(b569f890-78f1-42c2-b9d4-7082b45f45c8).html.

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Incompressible free-surface flows involving highly complex and violent phenomena are of great importance to the engineering industry. Applications such as breaking-wave impacts, fluid-structure interaction, and sloshing tanks demand an accurate and noise-free pressure field, and require large-scale simulations involving millions of computation points. This thesis addresses the need with the novel use of a graphics processing unit (GPU) to accelerate the incompressible smoothed particle hydrodynamics (ISPH) method for highly non-linear and violent free-surface flows using millions of particles in three dimensions. Compared to other simulation techniques, ISPH is robust in predicting a highly accurate pressure field, through the solution of a pressure Poisson equation (PPE), whilst capturing the complex behaviour of violent free-surface flows. However, for large-scale engineering applications the solution of extremely large PPE matrix systems on a GPU presents multiple challenges: constructing a PPE matrix every time step on the GPU for moving particles, overcoming the GPU memory limitations, establishing a robust and accurate ISPH solid boundary condition suitable for parallel processing on the GPU, and exploiting fast linear algebra GPU libraries. A new GPU-accelerated ISPH algorithm is presented by converting the highly optimised weakly-compressible SPH (WCSPH) code DualSPHysics and combining it with the open-source ViennaCL linear algebra library for fast solutions of the ISPH PPE. The challenges are addressed with new methodologies: a parallel GPU algorithm for population of the PPE matrix, mixed precision storage and computation, and extension of an existing WCSPH boundary treatment for ISPH. Taking advantage of a GPU-based algebraic multigrid preconditioner for solving the PPE matrix required modification for ISPH's Lagrangian particle system. The new GPU-accelerated ISPH solver, Incompressible-DualSPHysics, is validated through a variety of demanding test cases and shown to achieve speed ups of up to 25.3 times and 8.1 times compared to single and 16-threaded CPU computations respectively. The influence of free-surface fragmentation on the PPE matrix solution time with different preconditioners is also investigated. A profiling study shows the new code to concentrate the GPU's processing power on solving the PPE. Finally, a real-engineering 3-D application of breaking focused-wave impacting a surface-piercing cylindrical column is simulated with ISPH for the first time. Extensions to the numerical model are presented to enhance the accuracy of simulating wave-structure impact. Simulations involving over 5 million particles show agreement with experimental data. The runtimes are similar to volume-of-fluid and particle-in-cell solvers running on 8 and 80 processors respectively. The 3-D model enables post-processing analysis of the wave mechanics around the cylinder. This study provides a substantial step for ISPH. Incompressible-DualSPHysics achieves resolutions previously too impractical for a single device allowing for the simulation of many industrial free-surface hydrodynamic applications.
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Penzhorn, Karl. "Consistency and convergence of SPH approximations." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/12365.

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Includes bibliographical references (leaves 58-59).
Includes abstract.
This thesis is about a new approach to SPH. Instead of using a single kernel or shape function for approximation of a function and its derivatives, individual shape functions are used for each derivative. The investigation is carried out in one space dimension. After producing the conditions for consistency and convergence for the zeroth, first and second derivatives, a new set of linear or piecewise-linear shape functions which meet the minimum of these requirements are presented for each.
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Joshi, Shrey. "Modélisation de l'érosion de cavitation par SPH." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI080/document.

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La thèse est organisée autour du développement d'un modèle numérique d’interaction fluide - structure pour simuler la déformation induite dans un matériau solide lors de l’implosion de bulles de cavitation. Le solveur est développé à partir du code open source SPHYSICS_2D utilisant la méthode des Smoothed Particles Hydrodynamics (SPH). Dans cette thèse, le code 2D a été modifié pour traiter le cas de fluides en conditions 2D-axisymétrique. Le solveur solide SPH a été complètement développé en interne en 2D-axisymétrique avec un nouveau schéma pour résoudre les problèmes apparaissant à proximité de l'axe de symétrie. Une loi de comportement élasto-visco-plastique de type Johnson Cook est implémentée dans le solveur solide afin de prendre en compte l’effet de la vitesse de déformation sur l’écrouissage du matériau.Les applications du solveur FSI traitent le cas d’une bulle unique implosant au voisinage d’une surface solide. Deux cas sont envisagés : celui d’une bulle détachée de la surface solide pour laquelle l’effondrement génère une onde de choc ; et celui d’une bulle au contact de la surface pour lequel un micro-jet de liquide vient impacter la surface solide. Pour une taille de bulle donnée, les résultats montrent que le micro-jet peut produire deux fois solide pour laquelle l’effondrement génère une onde de choc ; et celui d’une bulle au contact de la surface pour lequel un micro-jet de liquide vient impacter la surface solide. Pour une taille de bulle donnée, les résultats montrent que le micro-jet peut produire deux fois plus de déformation plastique que l'onde de choc, réduisant ainsi le temps d'incubation. Par contre, le volume de matière déformée plastiquement dans le cas du micro-jet (cavité attachée) est 800 fois plus petit que celui déformé par l’impact d'une onde de choc (cavité détachée). Par conséquent, la capacité d'érosion d'une cavité détachée est beaucoup plus élevée que celle d'une cavité attachée. Un important résultat de cette étude concerne les cavités détachées où il est montré que la déformation plastique ne se produit pas au centre de l'effondrement mais à un décalage par rapport à l’axe de symétrie. Les résultats montrent également que même si la pression subie par le matériau est la plus élevée au niveau de l’axe de symétrie, la déformation plastique ne sera pas maximale à cet endroit mais dans une zone éloignée du centre. Nous Une étude paramétrique est menée pour quantifier les effets de la distance bulle/paroi, de la pression d’effondrement et du rayon de la bulle. Les résultats montrent que l'énergie totale absorbée et le taux d'érosion devraient être plus élevés pour une cavité détachée que pour une cavité attachée. La densité d'énergie absorbée (d'où le temps d'incubation) et l'énergie totale absorbée (d'où le taux d'érosion) augmentent avec la pression d’effondrement. Le changement du rayon de la bulle tout en gardant les autres paramètres constants n'affecte pas beaucoup l'amplitude de la déformation plastique ni la densité d'énergie absorbée, ce qui suggère que quelle que soit la taille de la bulle de cavitation, le temps d'incubation devrait rester similaire. Cependant, comme le volume de la zone déformée plastiquement varie presque linéairement avec la taille de la bulle, l'énergie totale absorbée ou le taux d'érosion augmente significativement avec la taille de la bulle.Dans le passé, les études similaires n'ont jamais pris en compte la sensibilité à la vitesse de déformation dans le modèle de plasticité. Nos simulations montrent que l'ampleur de la déformation plastique est alors surestimée d'environ 60% pour les cavités détachées présentées dans ce document et d'environ 200% pour les cavités attachées. Nous montrons ainsi que de telles études réductrices fondées sur des modèles de plasticité insensibles à la vitesse de déformation conduisent à une sous-estimation du temps d'incubation et à une surestimation du taux d'érosion
The thesis is focused on development of a Smoothed Particle Hydrodynamics (SPH) Fluid-Structure Interaction (FSI) cavitation solver to understand the phenomenon of material deformation under cavitation load better. This summary presents a brief overview of the methodology used to solve a fluid-structure interaction simulation of a bubble collapse over a deformable solid medium. The fluid solver and the solid solver are validated against Rayleigh-Plesset spherical bubble collapse case and FEM solver respectively. The fluid solver is developed using an open source SPH code SPHYSICS_2D, the code is changed from 2D to 2D axisymmetric. The solid SPH solver is developed in-house in 2D axisymmetric, a novel scheme is derived to solve typical issues near symmetry axis in the solid axisymmetric SPH solver. The solid solver has the capability to solve for non-linear isotropic hardening with strain rate effects (commonly known as Johnson-Cook plasticity model).A case each for a detached and an attached cavity is simulated using the FSI solver, the results show that for the same magnitude of pressure wave initiating the collapse and the same size of the bubble, the micro-jet can produce twice the maximum plastic deformation compared to a shock wave, hence a micro-jet dominated impact would exhibit a smaller incubation time compared to the detached cavity. It is also observed that the volume of material that is plastically deformed in case of a micro-jet is miniscule compared to a shock wave impact (almost 800 times smaller). This would imply that even though the incubation time for material erosion might be lower for a micro jet collapse, the shock wave can plastify a much larger volume of material and so the erosion rate should be higher for a shock wave impact. Hence it could be inferred that the material erosion ability of a shock wave is much higher than a micro-jet.An important and novel finding in the present study is the response of the material for a detached cavity where plastic deformation does not occur at the center of collapse but at an offset from the center. The results show that even though the pressure experienced by the material is the highest at the center, it does not produce the maximum plastic deformation. This is for the first time that such a phenomenon is reported in cavitation studies, we find that the phenomenon is linked to inertial effects where the material does not respond to the load as the rate of loading and unloading is extremely high. The effect is linked to the high loading and unloading rate near the center of the collapse due to the flat geometry of the solid medium. The study clearly demonstrate that maximum pressure does not always correspond to the location of maximum plastic deformation or material erosion.Fluid-Structure Interaction simulations for different stand-off ratios, driving pressure and bubble radius have been computed. Results show that for varying stand-off ratio while keeping the bubble radius and driving pressure constant, the attached cavities (SR<=1) show a higher plastic strain magnitude and a higher absorbed energy density which would suggest a quicker incubation time. However, the volume of plastic defamation zone is much lower in attached cavities thus the total absorbed energy and the erosion rate would be higher for a detached cavity compared to an attached one.The strain rate effects suggest that the magnitude of plastic strain is over predicted while using plasticity models that do not use strain rate sensitivity. The over prediction of the magnitude of plastic strain of around 60% for detached cavities presented in the paper and around 200% for attached cavities presented in the paper is observed. This would lead to an under prediction of incubation time and over prediction of erosion rate while using strain rate insensitive plasticity models
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Viau, Serge. "Transfert radiatif numérique pour un code SPH." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ62106.pdf.

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Cullen, Lee. "SPH and its application to stellar disruption." Thesis, University of Leicester, 2010. http://hdl.handle.net/2381/8577.

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In this thesis we study Smoothed Particle Hydrodynamics (SPH) which is a numerical method for simulating fluid flow used widely in astrophysics. In SPH artificial viscosity is necessary for the correct treatment of shocks, but often generates unwanted dissipation away from shocks, particularly in poorly resolved flows. In this study we address this problem by refining the method proposed by Morris & Monaghan (1997). The new scheme uses the rate of change of the velocity divergence, Dt(∇•v), to indicate a shock and focuses on eliminating viscosity away from shocks. The new method works as least as well as any previous technique in the strong-shock regime, but becomes virtually inviscid away from shocks. In particular sound waves or oscillations of self-gravitating gas spheres are hardly damped over many periods. We also look at stability issues for SPH, in particular the well known clumping instability. We perform numerical tests of the stability analysis performed by Morris (1996) and find that there are bands of unstable regions as suggested by Read et al. (2010). We also demonstrate that a cored kernel can greatly reduce the clumping instability. Finally we apply the SPH method to extend the stellar disruption work of Lodato et al. (2009) to orbits with a range of pericentre distances. We find that the light curve produced by this disruption is closer to the predicted L ∝ t−5/3 (Rees, 1988) for encounters that are closer to the black hole than the tidal disruption radius. For encounters that are further from the black hole than the tidal disruption radius, the light curve deviates from this predicted power law. We also look at how elliptical orbits can effect the stability of the star. We find that in elliptical orbits a star can be disturbed further from the black hole than in the parabolic case. We then consider the fate of the S2 star and conclude that when it becomes a red giant and expands, S2 will be tidally disrupted.
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Books on the topic "SPH"

1

Huang, Yu, Zili Dai, and Weijie Zhang. Geo-disaster Modeling and Analysis: An SPH-based Approach. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44211-1.

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Projecthandleiding SPH: Projectgericht leren met de Schijf-van-Vijf. Soest: Nelissen, 2003.

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Pereira da Silva, Luciano, Messias Meneguette Junior, and Carlos Henrique Marchi. Numerical Solutions Applied to Heat Transfer with the SPH Method. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-28946-0.

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A, Simpson Carol, and Ames Research Center, eds. Comparison of speech intelligibility in cockpit noise using SPH-4 flight helmet with and without active noise reduction. Menlo Park, Calif: DEV AIR Technical Associates, 1990.

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Hyginus, Gaius Julius. Clarissimi viri Hyginii Poeticon astronomicon opus utilissimum foeliciter incipit: De mundi & sph[a]er[a]e ac utriumsq[ue] p[ar]tiu[m] declaratione. Valencia: V. García Editores, 1993.

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Trefethen, Anne E. Implementing the NAS CG benchmark on the SP1/SP2. Ithaca, N.Y: Cornell Theory Center, Cornell University, 1995.

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United States. National Aeronautics and Space Administration., ed. Final report submitted to National Aeronautics and Space Administration, Lyndon B. Johnson Space Center ... for research entitled Coupling of SPH and finite element codes for multi-layer orbital debris shield design. Austin, TX: Dept. of Mechanical Engineering, University of Texas, 1997.

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McDonald, Stacey L. Copper-Catalyzed Electrophilic Amination of sp2 and sp3 C−H Bonds. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-38878-6.

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Indonesia. Departemen Transmigrasi dan Pemukiman Perambah Hutan. Pusat Penelitian dan Pengembangan., ed. Optimalisasi pemanfaatan lahan kritis di pemukiman transmigrasi: Kasus UPT Kelingi SP3 dan SP4. Jakarta: Pusat Penelitian dan Pengembangan, Departemen Transmigrasi dan PPH, 2000.

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ill, Golubeva Evgenia, ed. Shh. Shh. Shabbat. Minneapolis, MN: Lerner Publishing Group, 2016.

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Book chapters on the topic "SPH"

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Pardasani, R. T., and P. Pardasani. "Effective magnetic moment of [Co2(dppm)(μ-SPh)2(SPh)2]." In Magnetic Properties of Paramagnetic Compounds, 3510. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-23675-4_3172.

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Willibald, C. J., H. Rösner, H. Rahmann, and G. Schwarzmann. "Axonal Transport of Intraocularly Injected (3H-Sph)-GDla and (3H-Sph)-GMl." In Gangliosides and Modulation of Neuronal Functions, 323–24. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-71932-5_29.

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García-Senz, D., E. Bravo, and S. E. Woosley. "SPH Simulations of Thermonuclear Supernovae." In Thermonuclear Supernovae, 389–403. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5710-0_25.

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Randles, Philip W., Albert G. Petschek, Larry D. Libersky, and Carl T. Dyka. "Stability of DPD and SPH." In Lecture Notes in Computational Science and Engineering, 339–57. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-642-56103-0_24.

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Maddison, S. T., and J. J. Monaghan. "Simulating Dusty Gas Using SPH." In The Role of Dust in the Formation of Stars, 377–81. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-540-68594-4_79.

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Huang, Yu, Zili Dai, and Weijie Zhang. "SPH Models for Geo-disasters." In Geo-disaster Modeling and Analysis: An SPH-based Approach, 23–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44211-1_2.

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Huang, Yu, Zili Dai, and Weijie Zhang. "Validation of the SPH Models." In Geo-disaster Modeling and Analysis: An SPH-based Approach, 71–114. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44211-1_4.

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van Dam, Levi, and Mel Hoogendijk. "Inleiding in de methodiek SPH." In Methodiek sociaalpedagogische hulpverlening, 15–42. Houten: Bohn Stafleu van Loghum, 2011. http://dx.doi.org/10.1007/978-90-313-7648-3_2.

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Cruz Pérez, Juan Pablo, and José Antonio González Cervera. "Efficient Neighborhood Search in SPH." In Fluid Dynamics in Physics, Engineering and Environmental Applications, 185–99. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-27723-8_12.

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Verma, Kevin, and Robert Wille. "SPH on Multi-GPU Architectures." In High Performance Simulation for Industrial Paint Shop Applications, 101–13. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71625-7_9.

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Conference papers on the topic "SPH"

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Li, Mancang, Kan Wang, and Dong Yao. "The Super Equivalence Method in Monte Carlo Based Homogenization." In 2014 22nd International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/icone22-30882.

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The general equivalence theory (GET) and the superhomogenization method (SPH) are widely used for equivalence in the standard two-step reactor physics calculation. GET has behaved well in light water reactor calculation via nodal reactor analysis methods. The SPH was brought up again lately to satisfy the need of accurate pin-by-pin core calculations. However, both of the classical methods have their limitations. The super equivalence method (SPE) is proposed in the paper as an attempt to preserve the surface current, the reaction rates and the reactivity. It enhances the good property of the SPH method through reaction rates based normalization. The concept of pin discontinuity factors are utilized to preserve the surface current, which is the basic idea in the GET technique. However, the pin discontinuity factors are merged into the homogenized cross sections and diffusion coefficients, thus no additional homogenization parameters are needed in the succedent reactor core calculation. The eigenvalue preservation is performed after the reaction rate and surface current have been preserved, resulting in reduced errors of reactivity. The SPE has been implemented into the Monte Carlo method based homogenization code MCMC, as part of RMC Program, under developed in Tsinghua University. The C5G7 benchmark problem have been carried out to test the SPE. The results show that the SPE method not only suits for the equivalence in Monte Carlo based homogenization but also provides improved accuracy compared to the traditional GET or SPH method.
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Ceri, Samet, and Zahra Sharif Khodaei. "SPH and Adaptive FEM/SPH Methods in Debris Cloud Simulation." In 2022 16th Hypervelocity Impact Symposium. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/hvis2022-5.

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Abstract The Whipple shielding is the most common way to increase aerostructures safety by preventing main structures from the direct impact of the external threats which is broken into small pieces before reaching the witness plate. The diffusion of fragment pieces forms the debris cloud after the collision. It is necessary to understand debris cloud phenomenon to reduce the potential harmful consequence of the impact. To address this issue, it is important to have a reliable and efficient numerical tool to find the optimum shield design due to the high cost of the physical experiments. In this study, the traditional SPH and Adaptive FEM/SPH methods were compared based on the debris cloud’s feature and validated against the analytical model. Two different FEM/SPH adaptive models were used to understand the effect of the mesh regularity of the corresponding solid element. Results from this study indicate that the FEM/SPH adaptive method has lower computational cost than the traditional SPH method and the mesh regularity of the corresponding solid element is key point of the Adaptive FEM/SPH method. Yet, computational efficiency decreases with the increment in number of the element conversion.
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Ojal, Nishant, Harish P. Cherukuri, Tony L. Schmitz, and Adam W. Jaycox. "A Comparison of Smoothed Particle Hydrodynamics (SPH) and Coupled SPH-FEM Methods for Modeling Machining." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-24646.

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Abstract Smoothed Particle Hydrodynamics (SPH), a particle-based, meshless method originally developed for modeling astrophysical problems, is being increasingly used for modeling fluid mechanics and solid mechanics problems. Due to its advantages over grid-based methods in the handling of large deformations and crack formation, the method is increasingly being applied to model material removal processes. However, SPH method is computationally expensive. One way to reduce the computational time is to partition the domain into two parts where, the SPH method is used in one segment undergoing large deformations and material separation and in the second segment, the conventional finite element (FE) mesh is used. In this work, the accuracy of this SPH-FEM approach is investigated in the context of orthogonal cutting. The high deformation zone (where chips form and curl) is meshed with the SPH method, while the rest of the workpiece is modeled using the FE method. At the interface, SPH particles are coupled with FE mesh for smooth transfer of stress and displacement. The boundary conditions are applied to tool and FE zone of the workpiece. For comparison purposes, a fully-SPH model (workpiece fully discretized by SPH) is also developed. This is followed by a comparison of the results from the coupled SPH-FE model with the SPH model. A comparison of the chip profile, the cutting force, the von Mises stress and the damage parameter show that the coupled SPH-FE model reproduces the SPH model results accurately. However, the SPH-FE model takes almost 40% less time to run, a significant gain over the SPH model. Similar reduction in computation time is observed for in a micro-cutting application (depth of cut of 300 nm). Based on these results, it is concluded that coupling SPH with FEM in machining models decreases simulation time significantly while still producing accurate results. This observation suggests that three-dimensional machining problems can be modeled using the combined SPH-FEM approach without sacrificing accuracies.
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Balusu, Kranthi, Lei Li, Kyoo Sil Choi, and Ayoub Soulami. "Coupling Smoothed Particle Hydrodynamics With Finite Element Method to Simulate Residual Stresses From Friction Stir Processing." In ASME 2022 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/imece2022-93695.

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Abstract Friction stir processing (FSP) is a solid-state material processing technique that locally modifies the microstructure but also induces undesirable residual stresses. A robust numerical model for the FSP can help in mitigating these residual stresses. Heat source models within a finite element method (FEM) framework suffer from inaccuracies. In contrast, smoothed particle hydrodynamics (SPH) model that explicitly captures the material flow near the tool and the associated heat generation is accurate. However, the computational expense of SPH simulations can be prohibitive. In this work, we propose a coupled SPH-FEM framework. SPH is used to accurately model the heat generation near the tool, which is then inserted into the FEM model as a heat source. To verify this proposed coupling approach, a test case is set up with typical FSP conditions, and it is modeled in both SPH and SPH-FEM. The temperature profiles were compared after the simulations had reached steady-state temperatures. The similarity of the temperature profiles from SPH-FEM and SPH validated the proposed coupling approach. This proposed approach achieves the accuracy of the SPH method while potentially retaining the low computational expense of FEM.
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Topalovic, Marko, Aleksandar Nikolic, and Miroslav Zivkovic. "BLOOD FLOW SIMULATION USING SPH METHOD IN LS-DYNA, ANALYSIS OF ADVANTAGES AND DISADVANTAGES." In 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac,, 2021. http://dx.doi.org/10.46793/iccbi21.255t.

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The purpose of this research was to investigate the possibility of blood flow modelling in LS-DYNA using its SPH solver and SPH-FEM coupling. SPH and FEM methods are both based on the continuum mechanics, and SPH uses Lagrangian material framework, while FEM can use both Lagrangian for solid, and Eulerian formulation for fluid analysis. SPH implementation is mesh-free giving it the capability to model very large deformations without mesh distortions. However, this comes at a high computational price, so the number of SPH particles needs to be significantly lower in comparison to the number of FEM elements in the Eulerian analysis of the same fluid domain. In the case of combined SPH-FEM analysis, the blood vessel wall is modelled with FEM shell elements, while the blood inside is modelled with SPH particles. The contact between the two is done using nodes to surface algorithm, while if we use the SPH only, there is no need for the specific contact definition. The Lagrangian framework of the SPH method means that we need to generate particles at one end, and to destroy them on the other, in order to generate a continuous fluid flow. To do this we used activation and deactivation planes, which is a solution implemented in the commercial LS-Dyna SPH solver. In the results section of the paper, the velocity field of blood obtained by implementation of described modelling methodology is shown. SPH-FEM coupling offers greater possibilities to study the effects of wall deformations, tracking of movement of solid particle inclusion, or mixing two different fluids, but it requires elaborate contact definition, and prolonged analysis time in comparison to the FEM CFD analysis.
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le Touzé, David, Daniel A. Barcarolo, Matthieu Kerhuel, Guillaume Oger, Nicolas Grenier, Nathan Quinlan, Libor Lobovsky, et al. "Smoothed Particle Hydrodynamics: Benchmarking on Selected Test Cases Within the NextMuSE Initiative." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10811.

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In this paper are presented comparisons of SPH variants on academic test cases classically used to validate numerical fluid dynamics software. These comparisons are extracted from NextMuSE FP7 project activities which will be published more extensively in the near future. One of the goals of this project was to better understand the SPH method and to leave the path to its establishment within CFD methods. An important work load was thus dedicated to benchmark SPH variants on selected test cases. A number of results and conclusions of this comparative study are presented in this paper. The studied variants are: standard weekly-compressible SPH, δ-SPH, Riemann-SPH, incompressible SPH, and FVPM. The majority of the test cases also present a reference solution, either experimental or computed using a mesh-based solver. Test cases include: wave propagation, flow past a cylinder, jet impact, floating body, bubble rise, dam break on obstacle, floating body dynamics, etc. Conclusions may help SPH practitioners to choose one variant or another and shall give detailed understanding necessary to derive further improvements of the method.
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Solenthaler, B., and R. Pajarola. "Predictive-corrective incompressible SPH." In ACM SIGGRAPH 2009 papers. New York, New York, USA: ACM Press, 2009. http://dx.doi.org/10.1145/1576246.1531346.

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Reinhardt, Stefan, Markus Huber, Bernhard Eberhardt, and Daniel Weiskopf. "Fully asynchronous SPH simulation." In SCA '17: The ACM SIGGRAPH / Eurographics Symposium on Computer Animation. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3099564.3099571.

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Lescoe, Ryan, Moustafa El-Gindy, Kevin Koudela, Fredrik O¨ijer, Mukesh Trivedi, and Inge Johansson. "Tire-Soil Modeling Using Finite Element Analysis and Smooth Particle Hydrodynamics Techniques." In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28002.

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New soil models for a tire-soil interaction are developed and compared. A rigid tire model is used to perform an extensive sensitivity study on the previously used Finite Element Analysis (FEA) soft soil (dense sand) to determine the importance of mesh size, soil plot size, and edge constraints. Furthermore, parameters for Smooth Particle Hydrodynamics (SPH) particles are determined for either complete or partial replacement of FEA elements in the soil model. Rolling resistance tests are then conducted for different FEA, SPH, and FEA/SPH soil models. Replacement of FEA elements with SPH particles is isolated as a variable and it is found that using a deeper amount of SPH particles increases rolling resistance while increasing the SPH particle density has little effect on rolling resistance.
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10

Tajdari, Mahsa, and Bruce L. Tai. "Modeling of Brittle and Ductile Materials Drilling Using Smoothed-Particle Hydrodynamics." In ASME 2016 11th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/msec2016-8801.

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The objective of this study is to investigate smoothed particle hydrodynamics (SPH) method in simulating drilling process of both brittle and ductile materials. Drilling simulation is commonly performed by finite element method (FEM); however, it is challenging when applied to small debris generated by brittle materials or special cutting tools, due to the inability to capture small chip interactions. SPH was originally developed for flow analysis but has been recently used in cutting research. In this study, SPH is compared with FEM by four case studies. The results show that SPH can simulate ductile drilling, but the chip formation and forces are not as reasonable as FEM. On the other hand, SPH can capture small fragmented debris in brittle material drilling, which cannot be done by FEM with an equivalent mesh size. SPH method is also found to be affected by the distance between the particles (element size in FEM) and numerical errors on the free surfaces, both of which require further investigation beyond this paper.
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Reports on the topic "SPH"

1

Palmer, Ronald W., J. L. Haley, and Jr. SPH-4 Helmet Retention Assembly Reinforcement. Fort Belvoir, VA: Defense Technical Information Center, July 1988. http://dx.doi.org/10.21236/ada200432.

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Schryver, J. C., A. H. Primm, and S. C. Nelson. RAM simulation model for SPH/RSV systems. Office of Scientific and Technical Information (OSTI), December 1995. http://dx.doi.org/10.2172/206642.

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3

Swegle, J. W., and M. E. Kipp. SPH and Eulerian underwater bubble collapse simulations. Office of Scientific and Technical Information (OSTI), May 1998. http://dx.doi.org/10.2172/658192.

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4

Cloutman, L. D. SPH (smoothed particle hydrodynamics) simulations of hypervelocity impacts. Office of Scientific and Technical Information (OSTI), January 1991. http://dx.doi.org/10.2172/6025786.

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5

Lim, Hyun, and Julien Loiseau. FleCSPH : A New SPH Code Based on FleCSI Framework. Office of Scientific and Technical Information (OSTI), August 2017. http://dx.doi.org/10.2172/1375852.

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6

Palmer, Ronald W. SPH-4 Aircrew Helmet Impact Protection Improvements 1970-1990. Fort Belvoir, VA: Defense Technical Information Center, February 1991. http://dx.doi.org/10.21236/ada233784.

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7

Sen, Ramazan Sonat, Andrew John Hummel, and Hikaru Hiruta. SuPer-Homogenization (SPH) Corrected Cross Section Generation for High Temperature Reactor. Office of Scientific and Technical Information (OSTI), March 2017. http://dx.doi.org/10.2172/1369365.

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Morris, J. Technical Note: Description of Surface Tension as Implemented In LDEC-SPH Module. Office of Scientific and Technical Information (OSTI), February 2009. http://dx.doi.org/10.2172/948975.

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9

Lim, Hyun. FleCSPH : A New SPH Code Based on FleCSI Framework for Multi-physics Problems. Office of Scientific and Technical Information (OSTI), September 2018. http://dx.doi.org/10.2172/1475301.

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McMullen, Ryan, and John Torczynski. Feasibility of the LAMMPS SPH Package for Simulating Bubble Motion in Vibrating Containers. Office of Scientific and Technical Information (OSTI), June 2021. http://dx.doi.org/10.2172/1787742.

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