Relevant bibliographies by topics / Ω-automata

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Book chapters
  4. Conference papers

Academic literature on the topic 'Ω-automata'

Author: Grafiati
Published: 25 May 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Ω-automata.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Ω-automata"

1

Krithivasan, Kamala, K. Sharda та Sandeep V. Varma. "Distributed ω-Automata". International Journal of Foundations of Computer Science 14, № 04 (2003): 681–98. http://dx.doi.org/10.1142/s0129054103001959.

Full text
Abstract:
In this paper, we introduce the notion of distributed ω-automata. Distributed ω-automata are a group of automata working in unison to accept an ω-language. We build the theory of distributed ω-automata for finite state automata and pushdown automata in different modes of cooperation like the t-mode, *-mode, = k-mode, ≤ k-mode and ≥ k-mode along with different acceptance criteria i.e. Büchi-, Muller-, Rabin- and Streett- acceptance criteria. We then analyze the acceptance power of such automata in all the above modes of cooperation and acceptance criteria. We present proofs that distributed ω-finite state automata do not have any additional power over ω-finite state automata in any of the modes of cooperation or acceptance criteria, while distributed ω-pushdown automata can accept languages not in CFLω. We give proofs for the equivalence of all modes of cooperation and acceptance criteria in the case of distributed ω-pushdown automata. We show that the power of distributed ω-pushdown automata is equal to that of ω-Turing Machines. We also study the deterministic version of distributed ω-pushdown automata. Deterministic ω-pushdown automata accept only languages contained in CFLω but distributed deterministic ω-pushdown automata can accept languages not in CFLω and have the same power as their nondeterministic counterparts. We also define distributed completely deterministic ω-pushdown automata and analyze their power.
APA, Harvard, Vancouver, ISO, and other styles
2

Baier, Christel, Marcus Grösser та Nathalie Bertrand. "Probabilistic ω-automata". Journal of the ACM 59, № 1 (2012): 1–52. http://dx.doi.org/10.1145/2108242.2108243.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Krithivasan, Kamala, та K. Sharda. "Fuzzy ω-automata". Information Sciences 138, № 1-4 (2001): 257–81. http://dx.doi.org/10.1016/s0020-0255(01)00150-5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

CARNINO, VINCENT, and SYLVAIN LOMBARDY. "FACTORIZATIONS AND UNIVERSAL AUTOMATON OF OMEGA LANGUAGES." International Journal of Foundations of Computer Science 25, no. 08 (2014): 1111–25. http://dx.doi.org/10.1142/s0129054114400279.

Full text
Abstract:
We extend the concept of factorization on finite words to ω-rational languages and show how to compute them. We define a normal form for Büchi automata and introduce a universal automaton for Büchi automata in normal form. We prove that, for every ω-rational language, this Büchi automaton, based on factorization, is canonical and that it is the smallest automaton that contains the morphic image of every equivalent Büchi automaton in normal form.
APA, Harvard, Vancouver, ISO, and other styles
5

Lindsay, Peter A. "On alternating ω-automata". Journal of Computer and System Sciences 36, № 1 (1988): 16–24. http://dx.doi.org/10.1016/0022-0000(88)90018-9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

KUPFERMAN, ORNA, GILA MORGENSTERN та ANIELLO MURANO. "TYPENESS FOR ω-REGULAR AUTOMATA". International Journal of Foundations of Computer Science 17, № 04 (2006): 869–83. http://dx.doi.org/10.1142/s0129054106004157.

Full text
Abstract:
We introduce and study three notions of typeness for automata on infinite words. For an acceptance-condition class γ (that is, γ is weak, Büchi, co-Büchi, Rabin, or Streett), deterministic γ-typeness asks for the existence of an equivalent γ-automaton on the same deterministic structure, nondeterministic γ-typeness asks for the existence of an equivalent γ-automaton on the same structure, and γ-powerset-typeness asks for the existence of an equivalent γ-automaton on the (deterministic) powerset structure – one obtained by applying the subset construction. The notions are helpful in studying the complexity and complication of translations between the various classes of automata. For example, we prove that deterministic Büchi automata are co-Büchi type; it follows that a translation from deterministic Büchi to deterministic co-Büchi automata, when exists, involves no blow up. On the other hand, we prove that nondeterministic Büchi automata are not co-Büchi type; it follows that a translation from a nondeterministic Büchi to nondeterministic co-Büchi automata, when exists, should be more complicated than just redefining the acceptance condition. As a third example, by proving that nondeterministic co-Büchi automata are Büchi-powerset type, we show that a translation of nondeterministic co-Büchi to deterministic Büchi automata, when exists, can be done applying the subset construction. We give a complete picture of typeness for the weak, Büchi, co-Büchi, Rabin, and Streett acceptance conditions, and discuss its usefulness.
APA, Harvard, Vancouver, ISO, and other styles
7

Engelfriet, Joost, та Hendrik Jan Hoogeboom. "X-automata on ω-words". Theoretical Computer Science 110, № 1 (1993): 1–51. http://dx.doi.org/10.1016/0304-3975(93)90349-x.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Chen, Zhe. "On the Generative Power of ω-Grammars and ω-Automata". Fundamenta Informaticae 111, № 2 (2011): 119–45. http://dx.doi.org/10.3233/fi-2011-557.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Löding, Christof, та Max Philip Stachon. "On Minimization and Learning of Deterministic ω-Automata in the Presence of Don’t Care Words". Fundamenta Informaticae 189, № 1 (2023): 69–91. http://dx.doi.org/10.3233/fi-222152.

Full text
Abstract:
We study minimization problems for deterministic ω-automata in the presence of don’t care words. We prove that the number of priorities in deterministic parity automata can be efficiently minimized under an arbitrary set of don’t care words. We derive that from a more general result from which one also obtains an efficient minimization algorithm for deterministic parity automata with informative right-congruence (without don’t care words). We then analyze languages of don’t care words with a trivial right-congruence. For such sets of don’t care words it is known that weak deterministic Büchi automata (WDBA) have a unique minimal automaton that can be efficiently computed from a given WDBA (Eisinger, Klaedtke 2006). We give a congruence-based characterization of the corresponding minimal WDBA, and show that the don’t care minimization results for WDBA do not extend to deterministic ω-automata with informative right-congruence: for this class there is no unique minimal automaton for a given don’t care set with trivial right congruence, and the minimization problem is NP-hard. Finally, we extend an active learning algorithm for WDBA (Maler, Pnueli 1995) to the setting with an additional set of don’t care words with trivial right-congruence.
APA, Harvard, Vancouver, ISO, and other styles
10

La Torre, Salvatore, та Margherita Napoli. "Finite automata on timed ω-trees". Theoretical Computer Science 293, № 3 (2003): 479–505. http://dx.doi.org/10.1016/s0304-3975(02)00611-4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Ω-automata"

1

Renkin, Florian. "Transformations d’ω-automates pour la synthèse de systèmes réactifs". Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS227.

Full text
Abstract:
La synthèse vise à produire un système correct à partir de spécifications. Une approche pour résoudre ce problème consiste à traduire la spécification en un jeu de parité dont la stratégie gagnante encode le système. Dans cette thèse nous allons montrer deux méthodes permettant de produire des automates de parité. La première s'appuie sur l'amélioration et la combinaison de procédures nouvelles ou existantes. La seconde est un algorithme de Casares et al. apportant une garantie d'optimalité du résultat. Dans un deuxième temps, nous montrerons comment nous réduisons le système obtenu. Deux types de réductions seront abordées. La première permet d'obtenir un résultat optimal mais pas la seconde qui privilégie le temps de traitement. La troisième partie décrira des optimisations qui peuvent être utilisées pour certaines classes de spécifications<br>Synthesis aims to produce a correct system from specifications. One approach to solve this problem is to translate the specification into a parity game whose winning strategy encodes the system. In this thesis we will show two methods to produce parity automata. The first is based on improving and combining new or existing procedures. The second is an algorithm from Casares et al. providing a guarantee of optimal results. In a second step, we will show how we reduce the obtained system. Two types of reductions will be discussed. The first allows to obtain an optimal result but not the second which privileges the processing time. The third part will describe optimizations that can be used for certain classes of specifications
APA, Harvard, Vancouver, ISO, and other styles
2

Sickert, Salomon [Verfasser], Estaun Francisco Javier [Akademischer Betreuer] Esparza, Estaun Francisco Javier [Gutachter] Esparza та Orna [Gutachter] Kupferman. "A Unified Translation of Linear Temporal Logic to ω-Automata / Salomon Sickert ; Gutachter: Francisco Javier Esparza Estaun, Orna Kupferman ; Betreuer: Francisco Javier Esparza Estaun". München : Universitätsbibliothek der TU München, 2019. http://d-nb.info/119416305X/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Pezzotti, Simone. "DFT-MD simulations and theoretical SFG spectroscopy to characterize H-Bonded networks at aqueous interfaces : from hydrophobic to hydrophilic environments Structural definition of the BIL and DL: a new universal methodology to rationalize non-linear χ(2)(ω) SFG signals at charged interfaces, including χ(3)(ω) contributions What the Diffuse Layer (DL) Reveals in Non-Linear SFG Spectroscopy 2D H-Bond Network as the Topmost Skin to the Air-Water Interface Combining ab-initio and classical molecular dynamics simulations to unravel the structure of the 2D-HB-network at the air-water interface 2D-HB-Network at the air-water interface: A structural and dynamical characterization by means of ab initio and classical molecular dynamics simulations Spectroscopic BIL-SFG Invariance Hides the Chaotropic Effect of Protons at the Air-Water Interface Molecular hydrophobicity at a macroscopically hydrophilic surface Graph theory for automatic structural recognition in molecular dynamics simulations DFT-MD of the (110)-Co3O4 cobalt oxide semiconductor in contact with liquid water, preliminary chemical and physical insights into the electrochemical environment". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLE008.

Full text
Abstract:
Améliorer notre connaissance de la structure de l'eau dans l'environnement spécial offert par une interface est essentiel pour la compréhension de nombreux phénomènes naturels et applications technologiques. Pour révéler cette structure interfaciale de l'eau, des techniques capables de fournir des informations microscopiques, de manière sélective, pour cette couche interfaciale (BIL) sont nécessaires. Dans le présent travail de thèse, nous avons donc étudié les interfaces aqueuses au niveau moléculaire, en couplant la modélisation théorique à partir de simulations DFT-MD avec les spectroscopies SFG et THz-IR. En développant de nouveaux protocoles/outils d'investigation associant simulations DFT-MD et spectroscopie SFG, en particulier pour la rationalisation plus complexe des interfaces chargées, nous avons fourni une compréhension globale de l'effet des conditions interfaciales d'hydrophilicité, de pH, de force ionique sur le réseau des liaisons-H formé dans la couche interfaciale BIL, sur ses signatures spectroscopiques et sur son impact sur les propriétés physico-chimiques. Nous avons montré pour la première fois que, dans des conditions suffisamment hydrophobes, l'eau interfaciale crée des réseaux des liaisons-H bidimensionnels, révélé expérimentalement par les spectres THz-IR. Le réseau-2D dicte la dynamique de l'eau interfaciale, le potentiel de surface, l'acidité de surface, la tension superficielle et la thermodynamique d'hydratation des solutés hydrophobes. Cet "ordre horizontal" aux interfaces hydrophobes est opposé à "l'ordre verticale" obtenu aux interfaces hydrophiles. Nous avons aussi révélé comment les ions et les conditions de pH modifient ces arrangements structuraux<br>Improving our knowledge on water H-Bonded networks formed in the special environment offered by an interface is pivotal for our understanding of many natural phenomena and technological applications. To reveal the interfacial water arrangement, techniques able to provide detailed microscopic information selectively for the interfacial layer are required. In the present thesis work, we have hence investigated aqueous interfaces at the molecular level, by coupling theoretical modeling from DFT-MD simulations with SFG &amp; THz-IR spectroscopies. By developing new investigation protocols/tools, coupling DFT-MD simulations and SFG spectroscopy, in particular for the more complex rationalization of charged interfaces, we have provided a global comprehension of the effect of various interfacial conditions (hydrophilicity, pH, ionic strength) on the HB-Network formed in the interfacial layer (BIL), on its spectroscopic signatures and on its impact on physico-chemical properties. We have shown for the first time that, in sufficiently hydrophobic conditions, BIL interfacial water creates special 2-Dimensional HB-Networks, experimentally revealed by one specific THz-IR marker band. Such 2D-network dictates HBs and orientational dynamics of interfacial water, surface potential, surface acidity, water surface tension and thermodynamics of hydration of hydrophobic solutes. Such "horizontal ordering” of water at hydrophobic interfaces is found opposite to the “vertical ordering” of water at hydrophilic interfaces, while coexistence of the two orders leads to disordered interfacial water in intermediate hydrophilic/hydrophobic conditions. Both DFT-MD and SFG further revealed how ions &amp; pH conditions alter these BIL-water orders
APA, Harvard, Vancouver, ISO, and other styles
4

Segelken, Marc [Verfasser]. "Abstraktion und Gegenbeispiel-gelenkte Konstruktion von ω-Automaten [Omega-Automaten] zur Verifikation Schritt-diskreter linearer hybrider Systeme / von Marc Segelken". 2008. http://d-nb.info/989268985/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Ω-automata"

1

Farwer, Berndt. "ω-Automata." In Lecture Notes in Computer Science. Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/3-540-36387-4_1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Wilke, Thomas, and Sven Schewe. "ω-Automata." In Handbook of Automata Theory. European Mathematical Society Publishing House, 2021. http://dx.doi.org/10.4171/automata-1/6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Villa, Tiziano, Nina Yevtushenko, Robert K. Brayton, Alan Mishchenko, Alexandre Petrenko, and Alberto Sangiovanni-Vincentelli. "Equations Over ω-Automata." In The Unknown Component Problem. Springer US, 2011. http://dx.doi.org/10.1007/978-0-387-68759-9_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Casares, Antonio, Alexandre Duret-Lutz, Klara J. Meyer, Florian Renkin, and Salomon Sickert. "Practical Applications of the Alternating Cycle Decomposition." In Tools and Algorithms for the Construction and Analysis of Systems. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99527-0_6.

Full text
Abstract:
AbstractIn 2021, Casares, Colcombet, and Fijalkow introduced the Alternating Cycle Decomposition (ACD) to study properties and transformations of Muller automata. We present the first practical implementation of the ACD in two different tools, Owl and Spot, and adapt it to the framework of Emerson-Lei automata, i.e., $$\omega $$ ω -automata whose acceptance conditions are defined by Boolean formulas. The ACD provides a transformation of Emerson-Lei automata into parity automata with strong optimality guarantees: the resulting parity automaton is minimal among those automata that can be obtained by duplication of states. Our empirical results show that this transformation is usable in practice. Further, we show how the ACD can generalize many other specialized constructions such as deciding typeness of automata and degeneralization of generalized Büchi automata, providing a framework of practical algorithms for $$\omega $$ ω -automata.
APA, Harvard, Vancouver, ISO, and other styles
5

Almagor, Shaull, Yoram Hirshfeld, and Orna Kupferman. "Promptness in ω-Regular Automata." In Automated Technology for Verification and Analysis. Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-15643-4_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Yen, Hsu-Chun. "Fair Control of ω-Automata." In Discrete Event Systems. Springer US, 2000. http://dx.doi.org/10.1007/978-1-4615-4493-7_37.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Kupferman, Orna, Gila Morgenstern, and Aniello Murano. "Typeness for ω-Regular Automata." In Automated Technology for Verification and Analysis. Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-30476-0_27.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Krishnan, Sriram C., Anuj Puri, and Robert K. Brayton. "Structural complexity of ω-automata." In STACS 95. Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/3-540-59042-0_69.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Boker, Udi, Karoliina Lehtinen, and Salomon Sickert. "On the Translation of Automata to Linear Temporal Logic." In Lecture Notes in Computer Science. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99253-8_8.

Full text
Abstract:
AbstractWhile the complexity of translating future linear temporal logic (LTL) into automata on infinite words is well-understood, the size increase involved in turning automata back to LTL is not. In particular, there is no known elementary bound on the complexity of translating deterministic $$\omega $$ ω -regular automata to LTL.Our first contribution consists of tight bounds for LTL over a unary alphabet: alternating, nondeterministic and deterministic automata can be exactly exponentially, quadratically and linearly more succinct, respectively, than any equivalent LTL formula. Our main contribution consists of a translation of general counter-free deterministic $$\omega $$ ω -regular automata into LTL formulas of double exponential temporal-nesting depth and triple exponential length, using an intermediate Krohn-Rhodes cascade decomposition of the automaton. To our knowledge, this is the first elementary bound on this translation. Furthermore, our translation preserves the acceptance condition of the automaton in the sense that it turns a looping, weak, Büchi, coBüchi or Muller automaton into a formula that belongs to the matching class of the syntactic future hierarchy. In particular, it can be used to translate an LTL formula recognising a safety language to a formula belonging to the safety fragment of LTL (over both finite and infinite words).
APA, Harvard, Vancouver, ISO, and other styles
10

Peng, Wuxu, and S. Purushothaman. "Empty stack Pushdown ω-tree automata." In CAAP '92. Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/3-540-55251-0_14.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Ω-automata"

1

Safra, S., та M. Y. Vardi. "On ω-automata and temporal logic". У the twenty-first annual ACM symposium. ACM Press, 1989. http://dx.doi.org/10.1145/73007.73019.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Lehtinen, Karoliina, та Martin Zimmermann. "Good-for-games ω-Pushdown Automata". У LICS '20: 35th Annual ACM/IEEE Symposium on Logic in Computer Science. ACM, 2020. http://dx.doi.org/10.1145/3373718.3394737.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Liu, Ying, та Hede Ma. "Pattern recognition using ω-orbit finite automata". У Visual Communications, '91, Boston, MA, редактори Kou-Hu Tzou та Toshio Koga. SPIE, 1991. http://dx.doi.org/10.1117/12.50318.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Bouyer, Patricia, Antonio Casares, Mickael Randour, and Pierre Vandenhove. "Half-Positional Objectives Recognized by Deterministic Büchi Automata (Extended Abstract)." In Thirty-Second International Joint Conference on Artificial Intelligence {IJCAI-23}. International Joint Conferences on Artificial Intelligence Organization, 2023. http://dx.doi.org/10.24963/ijcai.2023/713.

Full text
Abstract:
In two-player zero-sum games on graphs, the protagonist tries to achieve an objective while the antagonist aims to prevent it. Objectives for which both players do not need to use memory to play optimally are well-understood and characterized both in finite and infinite graphs. Less is known about the larger class of half-positional objectives, i.e., those for which the protagonist does not need memory (but for which the antagonist might). In particular, no characterization of half-positionality is known for the central class of ω-regular objectives. Here, we characterize objectives recognizable by deterministic Büchi automata (a class of ω-regular objectives) that are half-positional, both over finite and infinite graphs. This characterization yields a polynomial-time algorithm to decide half-positionality of an objective recognized by a given deterministic Büchi automaton.
APA, Harvard, Vancouver, ISO, and other styles
5

Safra, Shmuel. "Exponential determinization for ω-automata with strong-fairness acceptance condition (extended abstract)". У the twenty-fourth annual ACM symposium. ACM Press, 1992. http://dx.doi.org/10.1145/129712.129739.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Labai, Nadia, Magdalena Ortiz, and Mantas Šimkus. "An ExpTime Upper Bound for ALC with Integers." In 17th International Conference on Principles of Knowledge Representation and Reasoning {KR-2020}. International Joint Conferences on Artificial Intelligence Organization, 2020. http://dx.doi.org/10.24963/kr.2020/61.

Full text
Abstract:
Concrete domains, especially those that allow to compare features with numeric values, have long been recognized as a very desirable extension of description logics (DLs), and significant efforts have been invested into adding them to usual DLs while keeping the complexity of reasoning in check. For expressive DLs and in the presence of general TBoxes, for standard reasoning tasks like consistency, the most general decidability results are for the so-called ω-admissible domains, which are required to be dense. Supporting non-dense domains for features that range over integers or natural numbers remained largely open, despite often being singled out as a highly desirable extension. The decidability of some extensions of ALC with non-dense domains has been shown, but existing results rely on powerful machinery that does not allow to infer any elementary bounds on the complexity of the problem. In this paper, we study an extension of ALC with a rich integer domain that allows for comparisons (between features, and between features and constants coded in unary), and prove that consistency can be solved using automata-theoretic techniques in single exponential time, and thus has no higher worst-case complexity than standard ALC. Our upper bounds apply to some extensions of DLs with concrete domains known from the literature, support general TBoxes, and allow for comparing values along paths of ordinary (not necessarily functional) roles.
APA, Harvard, Vancouver, ISO, and other styles
7

Catania, Giuseppe, and Giovanni Naldi. "Blade Modeling of an Axial Flow Fan Under Vibration Constraints: An Experimental and Analytical Investigation." In ASME 2002 Engineering Technology Conference on Energy. ASMEDC, 2002. http://dx.doi.org/10.1115/etce2002/struc-29043.

Full text
Abstract:
A fan blade automatic modelling and design technique is proposed. Starting from axial flow fan nominal head H, flow rate Q and revolution speed ω, a numerical constrained optimization procedure is proposed. Fluid-dynamic, as well as geometrical, structural and vibration constraints are taken into account in the evaluation of the optimal objective function. Details of the numerical implementation, as well as results concerning a real application example, are reported and discussed.
APA, Harvard, Vancouver, ISO, and other styles
8

Spall, Robert E., and Wenbin Yu. "Imbedded Dual-Number Automatic Differentiation to Support CFD Analysis." In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72043.

Full text
Abstract:
Dual number automatic differentiation was applied to two different computational fluid dynamics codes, one written specifically for this purpose and one larger “legacy” Fortran code. Results for the simple case of a fully developed laminar flow in a channel validated the accuracy of the approach in computing derivatives with respect to both a fluid property, and a geometric dimension. DNAD was also implemented into the JET Fortran program which is available with a popular turbulence modeling textbook as companion software. Mean centerline velocity derivatives for a self-similar round jet with respect to all applicable turbulence model closure coefficients for both k–ω and k–ε models were obtained. The method proved to be accurate and relatively simple to implement into both the new and legacy Fortran codes.
APA, Harvard, Vancouver, ISO, and other styles
9

Cheng, X., A. Batta, H. Y. Chen, and N. I. Tak. "Turbulent Heat Transfer to Heavy Liquid Metals in Circular Tubes." In ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56562.

Full text
Abstract:
The present paper gives a brief literature review on turbulent heat transfer in heavy liquid metals (HLM), especially liquid lead-bismuth eutectic (LBE). Some models available in the open literature on heat transfer and turbulent Prandtl number are assessed. In addition, CFD analysis is carried out for circular tube geometries. The effect of turbulence models, mesh structure and turbulent Prandtl number on the numerical results is studied. Application of ε-type turbulence models with scalable wall function shows less dependence of the numerical results on mesh structure than the ω-type turbulence models with automatic wall treatment. The turbulent Prandtl number affects strongly the heat transfer performance. Comparison between the CFD results, heat transfer correlations and heat transfer test data reveals a decrease in turbulent Prandtl number by increasing Reynolds number. Based on the results achieved, recommendations are made on correlations of heat transfer and turbulent Prandtl number for LBE flows.
APA, Harvard, Vancouver, ISO, and other styles
10

Briones, Alejandro M., and Brent A. Rankin. "Development of an Open-Source Autonomous CFD Meta-Modeling Environment for Small-Scale Combustor Optimization – Part II." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-78586.

Full text
Abstract:
Abstract This work presents an improved open-source autonomous CFD meta-modeling environment (OpenACME) for small-scale combustor design optimization. OpenACME couples several object-oriented programming open-source codes for CFD-assisted engineering design meta-modeling. OpenACME is fully automated and can be used in PC workstations or HPC clusters. OpenACME uses a global metaheuristic optimization algorithm based on multiple-objective evolutionary algorithm (i.e., NSGA-II). An initial design population is first computed with Latin Hypercube Sampling and subsequent iterations generate offspring based on tournament mating, uniform crossover, and polynomial mutation. OpenACME is capable of computing multiple parallel CFD design points concurrently, speeding up the meta-simulations. The CFD are based on steady-state, incompressible, three-dimensional simulations with multi-phase k-ω SST RANS and “frozen” flamelet progress variable (FFPV) combustion model. There are fifteen design variables. There are three meta-simulations. The meta-simulations report Pareto Frontier from which optimum designs can be selected based on thermodynamic cycle requirements. Conjugate heat transfer provides the most realistic liner temperature and combustor performance. Acritical is still recommended as a cost function when liner durability is a concern. OpenACME demonstrated to be a viable tool for combustor design optimization.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Ω-automata' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography