Готові списки джерел за темами / Distance coalescence

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Добірка наукової літератури з теми "Distance coalescence"

Автор: Grafiati

Опубліковано: 11 березня 2023

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Статті в журналах з теми "Distance coalescence"

Yang, Zhi Yong, Jian Dong Li, and Guo Hua Zhang. "Numerical Simulation of Bubble Coalescence Based on VOF Method." Applied Mechanics and Materials 148-149 (December 2011): 814–17. http://dx.doi.org/10.4028/www.scientific.net/amm.148-149.814.

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This paper takes bubbles of bubble shell as research object, mainly studies two bubbles arranged in a vertical position. Applying VOF (volume of fluid) method to simulate interaction between two bubbles, analyses the effect of center distances and diameters on deformation and coalescence of bubbles. Results show that coalescence time of two bubbles with same diameters increases as the center distance increases. To two bubbles with different diameters, when the bigger bubble located beneath at the initial time, the smaller bubble moves upward first and then moves downward before two bubbles coalesce. When the smaller bubble located beneath at the initial time, bubble coalescence cannot happen. This paper is the basis of bubble group research, it is of positive significance to the bubble group research and performance improvement of bubble shell.

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Wilkins, Jon F., and John Wakeley. "The Coalescent in a Continuous, Finite, Linear Population." Genetics 161, no. 2 (June 1, 2002): 873–88. http://dx.doi.org/10.1093/genetics/161.2.873.

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Abstract In this article we present a model for analyzing patterns of genetic diversity in a continuous, finite, linear habitat with restricted gene flow. The distribution of coalescent times and locations is derived for a pair of sequences sampled from arbitrary locations along the habitat. The results for mean time to coalescence are compared to simulated data. As expected, mean time to common ancestry increases with the distance separating the two sequences. Additionally, this mean time is greater near the center of the habitat than near the ends. In the distant past, lineages that have not undergone coalescence are more likely to have been at opposite ends of the population range, whereas coalescent events in the distant past are biased toward the center. All of these effects are more pronounced when gene flow is more limited. The pattern of pairwise nucleotide differences predicted by the model is compared to data collected from sardine populations. The sardine data are used to illustrate how demographic parameters can be estimated using the model.

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Wang, Yong Gang, Hong Liang He, Li Li Wang, and Fu Qian Jing. "Percolation-Relaxation Model with Critical Damage for Describing the Dynamic Tensile Spall of Ductile Metals." Key Engineering Materials 324-325 (November 2006): 121–24. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.121.

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In the framework of percolation theory, a simple void-coalescence model combined with the constitutive relations for describing the stress relaxation and material softening during the void-coalescence process, name as the percolation-relaxation (P-R) model, is proposed to describe the dynamic tensile spallation of ductile metals. A critical damage is introduced and coupled into the model to identify the onset of the void coalescence. Mesoscopically, the critical damage corresponds to the critical intervoid ligament distance (ILD), indicating the start of transition from the void-growth to the void-coalescence.

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Ahmed, Fatma, Nobuyuki Kawahara, and Eiji Tomita. "Binary collisions and coalescence of droplets in low-pressure fuel injector." Thermal Science, no. 00 (2020): 185. http://dx.doi.org/10.2298/tsci191120185a.

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The phenomena of binary collisions and coalescence of droplets was investigated from experimental studies but still are missing from real applications such as from fuel injector. The main purpose of the current study is to investigate the phenomena of binary collisions and coalescence of droplets from a practical port fuel injector (PFI). To accomplish this, direct microscopic images are taken from high-speed video camera coupled with a long-distance microscope and Barlow lens using the backlighting method. Experimental optimization of the spatial resolution and the depth -of -field of the long-distance microscope and Barlow lens are achieved. Experimental results from the direct microscopic images are compared with predictions from empirical equations for different collision regimes. Droplet sizes and velocities of experimental coalescence droplets from collisions are compared with the values predicted by the equations. The main results of this study are: The probability of collision and coalescence is very low in a PFI. The tangential velocity components of small droplets play an essential role in shape deformation during collisions and coalescence of the droplets. The previous published empirical equations to calculate dimensionless parameters, the Weber number (We), the droplet diameter ratio (?), and impact parameter (B) are applicable to the coalescence of droplets in a PFI.

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Fan, Pingyang, Jianxin Liu, Wengui Zuo, Min Wang, and Daoyong Zhang. "Experimental Study of Rock-like Materials with Two Unequal Parallel Preexisting Fissures under Uniaxial Compression." Applied Sciences 12, no. 20 (October 15, 2022): 10404. http://dx.doi.org/10.3390/app122010404.

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Fissures substantially impact the engineering stability of rock masses, making research on rock masses with preexisting fissures essential for engineering activities. The development of specimens with different preexisting fissure types was examined in this study. Three different types of specimens with preexisting fissures can be broadly categorized: specimens with few preexisting fissures, specimens with multiple preexisting fissures, and specimens with preexisting fissures and other flaws. Uniaxial compression tests of specimens with preexisting fissures of two unequal lengths were conducted, and the influence of preexisting fissure angle, the distance between the two fissures and fissure length on the peak strength and coalescence mode of specimens were analyzed. A large preexisting fissure length significantly influenced the peak strength and coalescence, and the uniaxial compressive strength (UCS) values of the rock-like materials decreased. In contrast, increasing the long preexisting fissure length influenced the crack propagation and coalescence more extensively in the case of a long preexisting fissure. The preexisting fissure angle and two preexisting fissure distances had a negligible effect on the UCS values of the rock-like materials. However, with increasing long preexisting fissure length, the short preexisting fissure was subject to crack propagation and coalescence.

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Rousset, François. "Genetic Differentiation and Estimation of Gene Flow from F-Statistics Under Isolation by Distance." Genetics 145, no. 4 (April 1, 1997): 1219–28. http://dx.doi.org/10.1093/genetics/145.4.1219.

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I reexamine the use of isolation by distance models as a basis for the estimation of demographic parameters from measures of population subdivision. To that aim, I first provide results for values of F-statistics in one-dimensional models and coalescence times in two-dimensional models, and make more precise earlier results for F-statistics in two-dimensional models and coalescence times in one-dimensional models. Based on these results, I propose a method of data analysis involving the regression of FST/ (1 – FST) estimates for pairs of subpopulations on geographic distance for populations along linear habitats or logarithm of distance for populations in two-dimensional habitats. This regression provides in principle an estimate of the product of population density and second moment of parental axial distance. In two cases where comparison to direct estimates is possible, the method proposed here is more satisfactory than previous indirect methods.

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Zhang, Fangfang, and Hongjun Li. "Visualization of Coalescence of Multiple Small Bubbles with Closed B-Spline Curve." International Journal of Computer Games Technology 2020 (August 27, 2020): 1–13. http://dx.doi.org/10.1155/2020/8953893.

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The smoothness of surface shape is one of the key issues to simulate coalescence of underwater bubbles. In this paper, B-spline closed curve is used to realize the visual simulation of multibubble coalescence. The main idea of the proposed algorithm is to construct a continuous bubble deformation which is guided by the normal direction of each control point and weighted by the distance from the point to the geometry center of the contour. The advantages of this algorithm include the smoothness of the bubble contour in the processing of deformation and the randomness of dynamic process and coalescence process. Experiment results show that the simulation algorithm works well and can be used in 3D computer games and animations.

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Dai, Bing, Ying Chen, Guoyan Zhao, Weizhang Liang, and Hao Wu. "A Numerical Study on the Crack Development Behavior of Rock-Like Material Containing Two Intersecting Flaws." Mathematics 7, no. 12 (December 11, 2019): 1223. http://dx.doi.org/10.3390/math7121223.

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It is quite often that rocks contain intersecting cracks. Therefore, crack behavior cannot be completely studied by only considering several isolated, single flaws. To investigate the crack behavior of rock or rock-like material containing intersecting flaws under uniaxial loading, numerical simulations were carried out using parallel bonded-particle models containing two intersecting flaws with different inclination angles (varying β) and different intersection angles (varying αα). The crack propagation processes are analyzed and two typical patterns of linkage are observed between two intersecting flaws: (1) One-tip-linkage that contains three subtypes: Coalescence position near the tip; coalescence position at the flaw, but far away from the tip; coalescence position outside the flaw at a certain distance from the tip; and (2) two-tip-linkage with two subtypes: Straight linkage and arc linkage. The geometries of flaws influence the coalescence type. Moreover, the effects of intersection angle α and inclination angle β on the peak stress, the stress of crack initiation, and the stress of crack coalescence are also investigated in detail.

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Chen, Rou, Huidan(Whitney) Yu, and Likun Zhu. "Effects of initial conditions on the coalescence of micro-bubbles." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 3 (November 24, 2017): 457–65. http://dx.doi.org/10.1177/0954406217742941.

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The effects of initial conditions on the coalescence of two equal-sized air micro-bubbles ( R0) in water are studied using the lattice Boltzmann method. The focus is on effects of two initial set-ups of parent bubbles, separated by a small distance d and connected with a neck bridge radius r0, on the neck bridge growth at the early stage of the bubble coalescence. A sophisticated free energy lattice Boltzmann method model based on the Cahn-Hilliard diffuse interface approach is employed. This lattice Boltzmann method model has been demonstrated suitable for handling a large density ratio of two fluids up to 1000 and capable of minimizing the nonphysical spurious current. In both initial scenarios, the neck bridge evolution exhibits a half power-law scaling, [Formula: see text] after a development time. The half power-law agrees with the recent analytical prediction and experimental results. It has been found that smaller initial separation distance or smaller initial neck bridge radius results in faster growth of neck bridge and bubble coalescence, which is similar to the effects of these two initial scenarios on droplet coalescence. The physical mechanism behind each behavior has been explored. For the initial connected case, faster neck growth and longer development time corresponding to smaller initial neck radius is due to the significant bias between the capillary forces contributed by the meniscus curvature and the neck bridge curvature, whereas in the case of initial separated scenario, faster growth and shorter development time corresponding to shorter separation distance is due to the formation of elongated neck bridge. The prefactor A0 that represents the growth of neck bridge radius at the characteristic time ti captured in each case is in good agreement with the experimental results.

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Bustamante, Danilo E., Manuel Oliva, Santos Leiva, Jani E. Mendoza, Leidy Bobadilla, Geysen Angulo, and Martha S. Calderon. "Phylogeny and species delimitations in the entomopathogenic genus Beauveria (Hypocreales, Ascomycota), including the description of B. peruviensis sp. nov." MycoKeys 58 (September 9, 2019): 47–68. http://dx.doi.org/10.3897/mycokeys.58.35764.

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The genus Beauveria is considered a cosmopolitan anamorphic and teleomorphic genus of soilborne necrotrophic arthropod-pathogenic fungi that includes ecologically and economically important species. Species identification in Beauveria is difficult because of its structural simplicity and the lack of distinctive phenotypic variation. Therefore, the use of multi-locus sequence data is essential to establish robust species boundaries in addition to DNA-based species delimitation methods using genetic distance, coalescent, and genealogical concordance approaches (polyphasic approaches). In this regard, our study used multilocus phylogeny and five DNA-based methods to delimit species in Beauveria using three molecular makers. These polyphasic analyses allowed for the delimitation of 20–28 species in Beauveria, confirming cryptic diversity in five species (i.e. B. amorpha, B. bassiana, B. diapheromeriphila, and B. pseudobassiana) and supporting the description of B. peruviensis as a new taxon from northeastern Peru. The other five species were not evaluated as they did not have enough data (i.e. B. araneola, B. gryllotalpidicola, B. loeiensis, B. medogensis, and B. rudraprayagi). Our results demonstrate that the congruence among different methods in a polyphasic approach (e.g. genetic distance and coalescence methods) is more likely to show reliably supported species boundaries. Among the methods applied in this study, genetic distance, coalescent approaches, and multilocus phylogeny are crucial when establishing species boundaries in Beauveria.

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Більше джерел

Дисертації з теми "Distance coalescence"

Berestycki, Nathanaël. "Transition de phase pour la distance d'une marche aléatoire et applications à des problèmes de réarrangements génétiques." Paris 6, 2006. http://www.theses.fr/2006PA066236.

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Deora, Aakash. "Experimental Investigation of Effect of Viscosity on Aperiodic Bubbling from Submerged Capillary-Tube Orifices in Adiabatic Liquid Pools." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1563271814185849.

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Zeppilli, Giulia. "Metodi matematici per lo sviluppo di una nuova distanza genetica per inferire eventi demografici da dati di sequenziamento di popolazioni umane." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7952/.

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La tesi individua un metodo matematico per inferire alcuni eventi demografici relativi a popolazioni umane, attraverso l’analisi di dati, reali e simulati, e con strumenti di statistica e analisi numerica (Cluster Analysis, Analisi Discriminate, Analisi della varianza, Interpolazione).

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Частини книг з теми "Distance coalescence"

Roch, Sébastien. "On the Variance of Internode Distance Under the Multispecies Coalescent." In Comparative Genomics, 196–206. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-00834-5_11.

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Borom, Marcus P. "Role of Earth-Moon rotational dynamics in the shaping of the surface of our planet." In In the Footsteps of Warren B. Hamilton: New Ideas in Earth Science. Geological Society of America, 2022. http://dx.doi.org/10.1130/2021.2553(22).

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ABSTRACT The age of the Moon (1.55–1.78 b.y. old) as calculated from its regression as a function of geological time is much younger than the currently accepted age (ca. 4.52 Ga) determined by radiometric dating of lunar samples collected by Apollo astronauts. This discrepancy has posed a serious challenge for planetary scientists to account satisfactorily for the formation and subsequent breakup of Pangea. Conventional orbital models of the Earth-Moon system cannot explain why Pangea formed on only one hemisphere of Earth, whereas this study’s proposed two-stage rotation model can provide a plausible explanation. Calculations and a plot of the Earth-Moon separation distance against geologic age suggest that, during their first ~3.0 b.y., Earth and the Moon were mutually tidally locked, rotating as an integrated unit about a barycenter (designated as stage I rotation). Beginning 1.55 Ga, however, Earth disengaged from its tidal lock with the Moon and entered its current orbital mode (designated as stage II rotation). The dynamics associated with the two rotational modes of the Earth-Moon system throughout Earth’s history are hypothesized to constitute the driving forces for the migration and coalescence of landmasses during stage I rotation to create Pangea, and its ultimate breakup and drifting during stage II rotation.

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Тези доповідей конференцій з теми "Distance coalescence"

Watanabe, Keizo, Feng Che, and Masayuki Mutoh. "Coalescence of Droplets of an Ink Jet." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0771.

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Abstract Measurements of the velocity of ink jet droplets were made using a microscope in an experimental apparatus in which the nozzle is about 18 μ m in diameter. It was shown that the distance for the coalescence of droplets from the liquid jet increases with the increase of density of liquid. The equation of motion for the droplet is analyzed numerically by assuming the air velocity around a droplet, and trajectories are obtained. The results of numerical simulation for the coalescence correspond to the experimental results well. It is pointed out that the droplet stream stability is affected by the surface tension of the jet.

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Kamaya, Masayuki. "Evaluation of Coalescence Criteria for Parallel Cracks." In ASME 2002 Pressure Vessels and Piping Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/pvp2002-1206.

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When multiple cracks approach one another, the stress intensity factor (SIF) is likely to change due to the interaction of the stress field. Since the change in the SIF is not always conservative in structural reliability evaluations, this interaction between multiple cracks must be taken into account. Section XI of the ASME Boiler and Pressure Vessel Code (Sec. XI) provides a flaw characterization method for considering multiple crack interactions. In Sec. XI, adjacent cracks are replaced by a coalesced single combined crack if they are located within a certain distance. However, no systematic analysis of the SIF for interacting parallel surface cracks is provided. Furthermore, the background of the coalescence criterion prescribed in Sec. XI is not clear. In this study, the SIF of interacting parallel cracks was calculated using the finite element method. A coalescence criterion for parallel cracks was then proposed based on the calculation results. A simplified mesh generation method was adopted in order to improve the complexity of the mesh generating procedure, which uses a transitional mesh, referred to as a “Tie Block.”

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Fang, M., S. Chandra, and C. B. Park. "Remelting and Coalescence of Molten Metal Droplets Deposited on a Plate." In ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56321.

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An experimental study was conducted to study coalescence of molten tin droplet deposited on an aluminum plate that was moving horizontally. A pneumatic droplet generator was used to produce molten tin droplets on demand. Coalescence of droplets placed on a horizontally moving surface depended on both substrate temperature and the degree of overlap between droplets. Continuous beads could be produced if the substrate temperature was kept above 175°C and droplets overlapped by a distance equal to half their diameter. If either substrate temperature or droplet overlap distance was too small surface tension driven instabilities forced the bead to break up. A simple mass conservation model was used to predict the width of beads formed by droplet coalescence.

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Koizumi, Yasuo, Kenichiro Iitani, and Hiroyasu Ohtake. "Bubbling From Microscopic Holes Into Pool Water Simulating Nucleate Boiling: Bubble Coalescence and Water Layer Under the Coalescent Bubble." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33221.

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Air bubbling into stagnant water from microscopic holes was examined. As the blowing-out velocity was increased, bubbles became to coalescence each other after detachment from the holes and formed coalescent bubbles. Large bubbles departed from the coalescent bubbles intermittently. When the bubbles on the surface became large, the bubbles coalesced on the surface to form the coalescent-large bubble. The distance between the bottom wall and the coalescent bubble, which is often referred to as the thickness of the macro layer in the nucleate boiling, tended toward increasing with an increase in the blowing-out velocity contrary to the macro-layer theory. It was suggested that the occurrence of the CHF condition could be explained by combining the bubble crowding on the surface (the bubble crowding model) and the periodical leave of the coalescent bubble from the surface (the macro layer model).

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Huang, Ying, and Puzhen Gao. "A Numerical Simulation on Effects of Distance Between Bubble and the Wall on Behavior of Rising Bubble." In 2013 21st International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icone21-16641.

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A numerical investigation of two-dimensional air bubble behaviors under the effect of gravity in still water based on the VOF (Volume-Of-Fluid) method is carried out. Initially, the surface tension effects on the behavior of the bubble is analyzed, which contains the simulation of the ascending motion of a single air bubble in liquid and the study of the interaction between bubbles in terms of coalescence. Additionally, the differences of single bubble’s rising motion in an infinite surroundings and in a vertical narrow channel are analyzed. The coalescence of bubbles is also studied. The motion of bubbles with different diameters in a vertical channel is simulated. It is found that the bubbles’ behavior depends on the distance between the bubble and the wall. Finally, numerical simulation of the motion of several bubbles of the same size, at the same initial horizontal position and with uniform distribution is carried out. The result reveals that the bubbles at different distances from the wall have different velocities, after a while, the bubbles distribution presents as “U”.

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Ko¨hler, J. M., and P. A. Groß. "Microphotometric Characterization of Fluid Segment Populations Generated in Different Simple Microfluidic Networks." In ASME 4th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2006. http://dx.doi.org/10.1115/icnmm2006-96172.

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The stability of fluid segments is limited by deformation stress and by coalescence events. Both factors are typical for the passage of fluid segments through micro fluidic networks. Therefore, the coalescence behaviour of micro fluid segments in simple net work structures in dependence of flow rate ratios was investigated and characterized by the composition of obtained segment populations. Series of segments of different size and distance were generated either in a double T- or in a triple T-arrangement. PTFE elements were used for the micro fluid network. Nearly pulsation-free fluid actuation was realized by syringe pumps. The flow conditions in the input streams of carrier liquid and injected solutions remained constant during the experiments. Segment sequences become divers by different injection, stacking and coalescence events. The resulting segment sequences were characterized by on-line micro photometry. The populations of obtained micro fluid segments during each experiment were characterized by the distribution of segment size and segment distance or segment periode, respectively. Simulations support the assumption, that the character of segment populations is mainly determined by the flow rate ratios and by the coalescence sensitivity beside the topology of the fluidic network.

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Ma, Xuehu, Sifang Wang, Zhong Lan, Benli Peng, Tao Bai, and Hongbin Ma. "Pulsating and Bouncing off of Dropwise Condensate on Superhydrophobic Surface." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-65795.

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The steam dropwise condensation (DWC) characteristics on superhydrophobic plates were investigated experimentally in the presence of a high concentration noncondensable gas (NCG, >80mol%). The behaviors of condensate droplets on the roughness-induced superhydrophobic surface were observed with a photron high speed camera attached to a microscope. Pulsating features are found during droplets coalescence movement. Bouncing off of coalesced droplet was also observed induced by the strong effect of pulsating motion to overcome the pinning effect of the surface micro-nanostructures. Induced by the pulsating effect of droplets coalescence, the droplet can move at a long distance to join a coalesced droplet.

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Daly, Michael, Fabien Leonard, John K. Sharples, and Andrew H. Sherry. "Advanced Assessment of the Ductile Fracture Mechanism in A508 Class 3 Reactor Pressure Vessel Steel Using Laboratory X-Ray Tomography." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97924.

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Ductile damage is characterised by the nucleation, growth and coalescence of voids at initiating particles within the volume of high triaxial stresses and plastic strain ahead of a crack-tip or stress concentrator. To establish a more detailed understanding of the mechanism of ductile fracture in the A508 Class 3 ferritic RPV steels and to improve fracture models, the ductile damage was quantified below the fracture surface of tested compact test specimens using laboratory X-ray tomography imaging with sufficient resolution to image voids of approximately 10μm in diameter. The average distribution of void volume fraction as a function of distance below the fracture surface was quantified, and the initiating and coalescence mechanisms were characterised. The highest void volume fraction was observed at the fracture surface and this tends to decrease as a function of distance below the fracture surface. This decrease is periodically perturbed by large voids associated with inclusions which are distributed throughout the microstructure and act as further nucleating sites at low strains. This distribution of voids was correlated with the local variations in stress triaxiality and plastic strain derived from finite element analyses to provide a relationship between experimental observations and the Rice and Tracey model. These correlations aim to provide new data and understanding with which to calibrate mechanistically based models such as the Gurson-Tvergaard-Needleman (GTN) model.

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Zhu, Ren-qing, Yan-cheng Li, Yong-yan Ni, and Pei-tao Zhang. "Numerical Simulation of the Interaction Between Two Bubbles Rising in the Water." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-21064.

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Based on the VOF model, the rising movement and deformation of two bubbles placed horizontally or vertically with separation distance under the action of the buoyancy are simulated by using FLUENT software. The effects of distance between two bubbles on deformation, coalescence, rising velocity and path are considered. The bubble deformation is monitored and the change of velocity with time is analyzed. The influence of bubble diameter on rising and merging are discussed and the velocity history of bubble is obtained in rising and merging process. The results show that: The distance has great effect on the interaction between two bubbles in rising and merging process, the smaller the bubble spacing is, the stronger the interaction between bubbles is, and the larger the bubble diameter is, the larger the affected area is. The two bubbles placed vertically attract each other in rising process. The upper bubble has accelerative effect on the speed of lower bubble. The two bubbles placed horizontally in water attract and exclude each other periodically.

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Hong, Jin-Won, Jae-Boong Choi, and Nam-Su Huh. "Coalescence Pressure Evaluation of Multiple Through-Wall Cracks in Steam Generator Tube Using Elastic-Plastic Finite Element Analyses." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45451.

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Анотація:

During an in-service inspection, if multiple cracks have been found in a nuclear component, the crack interaction effect due to adjacent cracks should be taken into account to characterize the detected multiple cracks into equivalent single combined crack or independent single crack. However, there must be many factors to be considered to quantify crack interaction effect, many experimental and numerical works should be made to propose robust guidelines on crack interaction effect depending on material characteristics of interest. Although many works have been made during the past few years to evaluate crack interaction effect of steam generator tubes with multiple cracks, the robust guidelines are still lacking. In this study, systematic 3-dimensional (3D) elastic-plastic finite element (FE) analyses are performed for steam generator tubes with multiple through-wall cracks. As for geometries of multiple through-wall cracks, four different cases are considered; axial collinear cracks, axial parallel cracks, circumferential collinear cracks, and circumferential parallel cracks. The geometric variables affecting the Pc (coalescence pressure), i.e. crack length and distance between multiple cracks, are systematically varied in the present study. Based on the coalescence pressure evaluation model proposed by authors in the previous study and the present FE results, the Pc of steam generator tubes with multiple cracks are investigated.

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