Academic literature on the topic 'Rankin Vortex'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Rankin Vortex.'
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 "Rankin Vortex"
1
KONDOU, Shuuji, Hiroshi YAMASHITA, Masahisa SHINODA, and Kazuhiro YAMAMOTO. "A Numerical Study on Effect of Vortex Core Radius on Premixed Flame Propagation in Rankin Vortex Flow." Transactions of the Japan Society of Mechanical Engineers Series B 74, no. 747 (2008): 2387–92. http://dx.doi.org/10.1299/kikaib.74.2387.
Full text
2
Wood, Vincent T., and Luther W. White. "A Parametric Wind–Pressure Relationship for Rankine versus Non-Rankine Cyclostrophic Vortices." Journal of Atmospheric and Oceanic Technology 30, no. 12 (December 1, 2013): 2850–67. http://dx.doi.org/10.1175/jtech-d-13-00041.1.
Full textAbstract:
Abstract A parametric tangential wind profile model is presented for depicting representative pressure deficit profiles corresponding to varying tangential wind profiles of a cyclostrophic, axisymmetric vortex. The model employs five key parameters per wind profile: tangential velocity maximum, radius of the maximum, and three shape parameters that control different portions of the profile. The model coupled with the cyclostrophic balance assumption offers a diagnostic tool for estimating and examining a radial profile of pressure deficit deduced from a theoretical superimposing tangential wind profile in the vortex. Analytical results show that the shape parameters for a given tangential wind maximum of a non-Rankine vortex have an important modulating influence on the behavior of realistic tangential wind and corresponding pressure deficit profiles. The first parameter designed for changing the wind profile from sharply to broadly peaked produces the corresponding central pressure fall. An increase in the second (third) parameter yields the pressure rise by lowering the inner (outer) wind profile inside (outside) the radius of the maximum. Compared to the Rankine vortex, the parametrically constructed non-Rankine vortices have a larger central pressure deficit. It is suggested that the parametric model of non-Rankine vortex tangential winds has good potential for diagnosing the pressure features arising in dust devils, waterspouts, tornadoes, tornado cyclones, and mesocyclones. Finally, presented are two examples in which the parametric model is fitted to a tangential velocity profile, one derived from an idealized numerical simulation and the other derived from high-resolution Doppler radar data collected in a real tornado.
3
GORSHKOV, KONSTANTIN A., LEV A. OSTROVSKY, and IRINA A. SOUSTOVA. "Perturbation theory for Rankine vortices." Journal of Fluid Mechanics 404 (February 10, 2000): 1–25. http://dx.doi.org/10.1017/s0022112099007211.
Full textAbstract:
A perturbation scheme is constructed to describe the evolution of stable, localized Rankine-type hydrodynamic vortices under the action of disturbances such as density stratification. It is based on the elimination of singularities in perturbations by using the necessary orthogonality conditions which determine the vortex motion. Along with the discrete-spectrum modes of the linearized problem which can be kept finite by imposing the orthogonality conditions, the continuous-spectrum perturbations play a crucial role. It is shown that in a stratified fluid, a single (monopole) vortex can be destroyed due to the latter modes before it drifts very far, whereas a vortex pair preserves its stability for a longer time. The motion of the latter is studied in two cases: smooth stratification and a density jump. For the motion of a pair under a small angle to the interface, a complete description is given in the framework of our theory, including the effect of reflection of the pair from a region with slightly larger density.
4
Kuo, Hung-Chi, Wayne H. Schubert, Chia-Ling Tsai, and Yu-Fen Kuo. "Vortex Interactions and Barotropic Aspects of Concentric Eyewall Formation." Monthly Weather Review 136, no. 12 (December 1, 2008): 5183–98. http://dx.doi.org/10.1175/2008mwr2378.1.
Full textAbstract:
Abstract Concentric eyewall formation can be idealized as the interaction of a tropical cyclone core with nearby weaker vorticity of various spatial scales. This paper considers barotropic aspects of concentric eyewall formation from modified Rankine vortices. In this framework, the following parameters are found to be important in concentric eyewall formation: vorticity strength ratio, separation distance, companion vortex size, and core vortex skirt parameter. A vorticity skirt on the core vortex affects the filamentation dynamics in two important ways. First, the vorticity skirt lengthens the filamentation time, and therefore slows moat formation in the region just outside the radius of maximum wind. Second, at large radii, a skirted core vortex induces higher strain rates than a corresponding Rankine vortex and is thus more capable of straining out the vorticity field far from the core. Calculations suggest that concentric structures result from binary interactions when the small vortex is at least 4–6 times as strong as the larger companion vortex. An additional requirement is that the separation distance between the edges of the two vortices be less than 6–7 times the smaller vortex radius. Broad moats form when the initial companion vortex is small, the vorticity skirt outside the radius of maximum wind is small, and the strength ratio is large. In concentric cases, an outer vorticity ring develops when the initial companion vortex is large, the vorticity skirt outside the radius of maximum wind is small, and the strength ratio is not too large. In general, when the companion vortex is 3 times as strong as the core vortex and the separation distance is 4–6 times the radius of the smaller vortex, a core vortex with a vorticity skirt produces concentric structures. In contrast, a Rankine vortex produces elastic interaction in this region of parameter space. Thus, a Rankine vortex of sufficient strength favors the formation of a concentric structure closer to the core vortex, while a skirted vortex of sufficient strength favors the formation of concentric structures farther from the core vortex. This may explain satellite microwave observations that suggest a wide range of radii for concentric eyewalls.
5
Roy, Anubhab, and Ganesh Subramanian. "Linearized oscillations of a vortex column: the singular eigenfunctions." Journal of Fluid Mechanics 741 (February 20, 2014): 404–60. http://dx.doi.org/10.1017/jfm.2013.666.
Full textAbstract:
AbstractIn 1880 Lord Kelvin analysed the linearized inviscid oscillations of a Rankine vortex as part of a theory of vortex atoms. These eponymously named neutrally stable modes are, however, exceptional regular oscillations that make up the discrete spectrum of the Rankine vortex. In this paper, we examine the singular oscillations that make up the continuous spectrum (CS) and span the entire base state range of frequencies. In two dimensions, the CS eigenfunctions have a twin-vortex-sheet structure similar to that known from earlier investigations of parallel flows with piecewise linear velocity profiles. The vortex sheets are cylindrical, being threaded by axial lines, with one sheet at the edge of the core and the other at the critical radius in the irrotational exterior; the latter refers to the radial location at which the fluid co-rotates with the eigenmode. In three dimensions, the CS eigenfunctions have core vorticity and may be classified into two families based on the singularity at the critical radius. For the first family, the singularity is a cylindrical vortex sheet threaded by helical vortex lines, while for the second family it has a localized dipole structure with radial vorticity. The presence of perturbation vorticity in the otherwise irrotational exterior implies that the CS modes, unlike the Kelvin modes, offer a modal interpretation for the (linearized) interaction of the Rankine vortex with an external vortical disturbance. It is shown that an arbitrary initial distribution of perturbation vorticity, both in two and three dimensions, may be evolved as a superposition over the discrete and CS modes; this modal representation being equivalent to a solution of the corresponding initial value problem. For the restricted case of an initial axial vorticity distribution in two dimensions, the modal representation may be generalized to a smooth vortex. Finally, for the three-dimensional case, the analogy between rotational flows and stratified shear flows, and the known analytical solution for stratified Couette flow, are used to clarify the singular manner in which the modal superposition for a smooth vortex approaches the Rankine limit.
6
Jayavel, S., Pratish P. Patil, and Shaligram Tiwari. "Interaction of a skewed Rankine vortex pair." Physics of Fluids 20, no. 8 (August 2008): 083601. http://dx.doi.org/10.1063/1.2969115.
Full text
7
Wang, Lifeng, Ruifeng Hu, Jun Zhang, and Yunpeng Ma. "On the Vortex Detection Method Using Continuous Wavelet Transform with Application to Propeller Wake Analysis." Mathematical Problems in Engineering 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/242917.
Full textAbstract:
The method based on the continuous wavelet transformation to detect and characterize two-dimensional vortex is analyzed for a synthetic flow and applied to vortex detection of propeller wake. The characteristics of a vortex, such as center location, core radius, and circulation, are extracted based on the Lamb-Oseen and Rankine vortex models, the latter of which is a novel attempt. The effects of various factors such as the difference scheme, the grid and scale discretization, transform variable, and vortex model on vortex detection have been investigated thoroughly. The method is further applied to identify the tip vortex in a propeller wake.
8
Gorecki, Piotr, and Rathinam Panneer Selvam. "Rankine combined vortex interaction with a rectangular prism." International Journal of Computational Fluid Dynamics 29, no. 1 (January 2, 2015): 120–32. http://dx.doi.org/10.1080/10618562.2015.1010524.
Full text
9
Ali, Md Shahjahan, Takashi Hosoda, and Ichiro Kimura. "Unsteady RANS and LES Simulation of an Ideal Rankine Vortex Decay." Advances in Civil Engineering 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/523839.
Full textAbstract:
The 3D numerical simulation was carried out for an idealized Rankine vortex using nonlineark-εmodel (one kind of RANS model) and large eddy simulation (LES) techniques. In this 3D simulation, the vortex flow field was given to rotate with the vertical axis in a free surface rectangular domain. In order to investigate the predictability of standard (linear) and non-lineark-εmodels, the decay of a trailing vortex was simulated and compared with previous DNS data. The governing equations for mean velocities and turbulent flows were discretized with the finite volume method based on a staggered grid system. It was observed that in the growth phase as well as in stabilized phase of turbulence, the decay rate of tangential velocity by RANS model was well comparable with LES simulation as well as previous DNS data. However, in the decay phase of turbulence, RANS model showed slightly faster decay of tangential velocity due to its slower decay of turbulence compared to LES or DNS. The patterns as well as magnitudes of secondary currents predicted by RANS and LES models were well comparable to each other.
10
Zhou, Kai, and Chao Zhou. "Effects of upstream Rankine vortex on tip leakage vortex breakdown in a subsonic turbine." Aerospace Science and Technology 99 (April 2020): 105776. http://dx.doi.org/10.1016/j.ast.2020.105776.
Full textDissertations / Theses on the topic "Rankin Vortex"
1
YAMAMOTO, Kazuhiro, Masahisa SHINODA, Hiroshi YAMASHITA, Shuuji KONDOU, 和弘 山本, 昌久 篠田, 博史 山下, and 周司 近藤. "ランキン渦流中での予混合火炎伝播に与える渦核半径の影響に関する数値解析." 一般社団法人 日本機械学会, 2008. http://hdl.handle.net/2237/19800.
Full text
2
Supak, Kevin Robert. "Reduced gravity Rankine cycle system design and optimization study with passive vortex phase separation." Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2094.
Full textAbstract:
Liquid-metal Rankine power conversion systems (PCS) coupled with a fission reactor
remain an attractive option for space power applications because system specific power
and efficiency is very favorable for plant designs of 100 kW(e) or higher. Potential
drawbacks to the technology in a reduced gravity environment include two-phase fluid
management processes such as liquid-vapor phase separation. The most critical location
for phase separation is at the boiler exit where only vapor must be sent to the turbine
because blade erosion occurs from high velocity liquid droplets entrained by vapor flow.
Previous studies have proposed that rotary separators be used to separate the liquid and
vapor from a two phase mixture. However these devices have complex turbo machinery,
require kilowatts of power and are untested for high vapor flow conditions. The
Interphase Transport Phenomena (ITP) laboratory has developed a low-power, passive
microgravity vortex phase separator (MVS) which has already proven to be an essential
component of two-phase systems operating in low gravity environments.
This thesis presents results from flight experiments where a Rankine cycle was operated
in a reduced gravity environment for the first time by utilizing the MVS for liquid and
vapor phase separation. The MVS was able to operate under saturated conditions and
adjust to system transients as it would in the Rankine cycle by controlling the amount of
liquid and vapor within the device. A new model is developed for the MVS to predict
separation performance at high vapor flow conditions for sizing the separator at the boiler, condenser, and turbine locations within the cycle by using a volume limiting
method. This model factors in the following separator characteristics: mass, pumping
power, and available buffer volume for system transients. The study is concluded with
overall Rankine efficiency and performance changes due to adding vortex phase
separation and a schematic of the Rankine cycle with the integration of the MVS is
presented. The results from this thesis indicate the thermal to electric efficiency and
specific mass of the cycle can be improved by using the MVS to separate the two phases
instead of a rotary separator.
3
Donjat, David. "Étude et modélisation de l'hydrodynamique interne d'un injecteur mécanique de turboréacteur." Toulouse, ENSAE, 2003. http://www.theses.fr/2003ESAE0005.
Full textAbstract:
Avec les nouveaux enjeux en matière de pollution et de gain de puissance des turbomachines modernes, il est aujourd’hui nécessaire de maîtriser de façon optimale la combustion du carburant. Les nouvelles performances recherchées imposent donc aux motoristes un cahier des charges strict sur les systèmes d'injection. C’est dans le but d’optimiser le développement des systèmes d’injection à effet de pression de type tourbillonnaire double-débit utilisés dans les chambres de moteurs aéronautiques qu’un banc expérimental reproduisant, à grande échelle, les différents circuits constitutifs d’un tel injecteur a été mis en place à l'ONERA Centre de Toulouse. Une campagne d’essais a été effectuée afin de fournir une banque de données permettant une meilleure compréhension de la structure de l'écoulement interne d’un injecteur tourbillonnaire et de son influence sur l'atomisation du jet en sortie d’orifice. Les maquettes développées sont réalisées entièrement en matériau transparent, et sont constituées de différents modules interchangeables afin d’explorer plusieurs géométries. Des campagnes de mesure par fluorescence laser, par LDA et par PIV ont foumi une cartographie de l'écoulement interne révélant une architecture complexe fortement instationnaire. Schématiquement, le liquide à pulvériser entre dans une chambre dite à swirl via plusieurs fentes placées tangentiellement. L'application d’un important mouvement tourbillonnaire induit une structure de l'écoulement de type vortex de Rankine et se caractérise aussi par la formation d’une colonne d’air tout le long de l’axe. Par ailleurs, les instabilités de ce noyau d’air central ont pu être caractérisées : le caractère instationnaire des jets d'alimentation a une importance essentielle sur les origines des instabilités se propageant dans l'injecteur. En parallèle, ces données ont été exploitées avec l'objectif de valider un modèle 2D axisymétrique et un modèle 3D réalisés avec les logiciels Fluent 5. 7 et 6 suivant une méthode diphasique VOF d’ordre 2 avec reconstruction d'interface.
4
Aguirre, Miguel Angel. "Simulação numérica de tornados usando o método dos elementos finitos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/174397.
Full textAbstract:
O presente trabalho tem como objetivo estudar escoamentos de tornados e sua ação sobre corpos imersos empregando ferramentas numéricas da Engenharia do Vento Computacional (EVC). Os tornados constituem-se atualmente em uma das causas de desastres naturais no Brasil, especialmente nas regiões sul e sudeste do país, como também em alguns países vizinhos. Os efeitos gerados são geralmente localizados e de curta duração, podendo ser devastadores dependendo da escala do tornado. Tais características dificultam a realização de estudos detalhados a partir de eventos reais, o que levou ao desenvolvimento de modelos experimentais e numéricos. A abordagem numérica é utilizada neste trabalho para a simulação de tornados, a qual se baseia nas equações de Navier-Stokes e na equação de conservação de massa, considerando a hipótese de pseudo-compressibilidade e condições isotérmicas. Para escoamentos com turbulência utiliza-se a Simulação Direta de Grandes Escalas com o modelo clássico de Smagorinsky para as escalas inferiores à resolução da malha (Large Eddy Simulation ou LES em inglês). A discretização das equações fundamentais do escoamento se realiza com um esquema explícito de dois passos de Taylor-Galerkin, onde o Método dos Elementos Finitos é empregado na discretização espacial utilizando-se o elemento hexaédrico trilinear isoparamétrico com um ponto de integração e controle de modos espúrios Na presença de corpos imersos que se movem para simular os deslocamentos dos tornados, o escoamento é descrito cinematicamente através de uma formulação Arbitrária Lagrangeana-Euleriana (ALE) que inclui um esquema de movimento de malha. Tornados são reproduzidos através da simulação numérica de dispositivos experimentais e do Modelo de Vórtice Combinado de Rankine (RCVM). Exemplos clássicos da Dinâmica dos Fluidos Computacional são apresentados inicialmente para a verificação das ferramentas numéricas implementadas. Finalmente, problemas envolvendo tornados móveis e estacionários são analisados, incluindo sua ação sobre corpos imersos. Nos modelos baseados em experimentos, a variação da relação de redemoinho determinou os diferentes padrões de escoamento observados no laboratório. Nos exemplos de modelo de vórtice, quando o tornado impactou o corpo imerso gerou picos de forças em todas as direções e, após a passar pelo mesmo, produziu uma alteração significativa na estrutura do vórtice.Analyses of tornado flows and its action on immersed bodies using numerical tools of Computational Wind Engineering (CWE) are the main aims of the present work. Tornadoes are currently one of the causes of natural disasters in Brazil, occurring more frequently in the southern and southeastern regions of the country, as well as in some neighboring countries. Effects are usually localized, presenting a short time interval, which can be devastating depending on the scale of the tornado. These characteristics difficult to carry out detailed studies based on real events, leading to the development of experimental and numerical models. The numerical approach is used in this work for the simulation of tornadoes, which is based on the Navier-Stokes equations and the mass conservation equation, considering the hypothesis of pseudo-compressibility and isothermal conditions. For turbulent flows, Large Eddy Simulation (LES) is used with the classical Smagorinsky model for sub-grid scales Discretization is performed the explicit two-step Taylor-Galerkin scheme, where the Finite Element Method is used in spatial discretization using isoparametric trilinear hexahedral elements with one-point quadrature and hourglass control. In the presence of immersed bodies that are moving in order to simulate translating tornadoes, the flow is kinematically described through a Lagrangian-Eulerian Arbitrary (ALE) formulation, which includes a mesh motion scheme. Tornadoes are reproduced using numerical simulation of experimental devices and the Rankine Combined Vortex Model (RCVM). Classical examples of Computational Fluid Dynamics are presented initially for the verification of the numerical tools implemented here. Finally, problems involving moving and stationary tornadoes are analyzed, including their actions on immersed bodies. For models based on experiments, the variation of the swirl ratio determined the different flow patterns observed in the laboratory. In the vortex model examples, when the tornado impacted on the immersed body, peaks of forces were generated in all directions and, after passing over it, a significant change in the structure of the vortex was produced.
5
Rousseau, Marc-André. "Der Vorteil des ersten Zugriffs durch "Webpositioning" - das Internet als Schnittstelle von Markenrecht und Wettbewerbsrecht /." 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015917598&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full textBooks on the topic "Rankin Vortex"
1
de Sá Caetano, Elsa. Cable Vibrations in Cable-Stayed Bridges. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2007. http://dx.doi.org/10.2749/sed009.
Full textAbstract:
<p>The fifty years of experience of construction of cable-stayed bridges since their establishment as a new category among the classical types have brought an immense progress, ranging from design and conception to materials, analysis, construction, observation and retrofitting. The growing construction of cable-stayed bridges has also triggered researchers’ and designers’ attention to the problem of cable vibrations. Intensive research has been developed all over the world during the last two decades as a consequence of the numerous cases of cable vibrations exhibited by all types of cable-stayed bridges.<p>Despite the increased knowledge of the various vibration phenomena, most of the outcomes and research results have been published in journals and conference proceedings and scarce information is currently provided by the existing recommendations and codes. <p>The present book provides a comprehensive survey on the governing phenomena of cable vibration, both associated with direct action of wind and rain: buffeting, vortex-shedding, wake effects, rain-wind vibration; and resulting from the indirect excitation through anchorage oscillation: external and parametric excitation. Methodologies for assessment of the effects of those phenomena are presented and illustrated by practical examples. Control of cable vibrations is then discussed and state-of-art results on the design of passive control devices are presented. <p>The book is complemented with a series of case reports reflecting the practical approach shared by experienced designers and consultants: Yves Bournand (VSL International), Chris Geurts (TNO), Carl Hansvold (Johs. Holt), Allan Larsen (Cowi) and Randall Poston (WDP & Associates).
2
Offer, Avner. Consumption and Well-Being. Edited by Frank Trentmann. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780199561216.013.0034.
Full textAbstract:
Consumption defines the standard of living – whether food is hot or cold, whether walls are dry or damp. It is the stuff of desires and dreams. It signals superiority, but also community. It drives policy and vexes scholars. But consumption is not consummation. Its purpose recedes even as it is being realized. If insatiability is the vortex at the heart of consumption, there are also other problems. In standard economic theory, consumers rank preferences in the present, but the most significant choices arise not between two immediate substitutes (say coffee or tea), but between the present and the future. This article opens with some standard assumptions about the benefits of consumption, and competing ones about its futility. It discusses the findings of social and behavioural research on consumption and well-being, the link between happiness and wealth, relative income, habituation, materialism, history and culture, advertising, myopia, narcissism, and individualism.
Book chapters on the topic "Rankin Vortex"
1
Shinbrot, Troy. "Intermezzo: Effects of Increasing Reynolds Number." In Biomedical Fluid Dynamics, 141–75. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198812586.003.0007.
Full textAbstract:
Effects of increasing fluid speed are analyzed. The Bernouilli and vorticity equations are derived, and the method of matching solutions is described for the Rankine vortex. Cases in which rotational flow is mandatory are explained, and bifurcations, hydraulic jumps, and transitions between stable and unstable behaviors are introduced. The ethical views of Hans Bethe and Edward Teller are contrasted. Other topics include potential flow around both cylinders and spheres and lessons that can be learnt about flow over a wavy streambed.
2
"Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico." In Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico, edited by GLENN R. PARSONS and DANIEL G. FOSTER. American Fisheries Society, 2007. http://dx.doi.org/10.47886/9781888569971.ch5.
Full textAbstract:
<em>Abstract.</em>—We examined the swimming performance and behavior of red snapper, <em>Lutjanus campechanus. </em>Our intention was to use this information toward developing a more efficient bycatch reduction device for use in the Gulf of Mexico shrimp trawl fishery. Using a Brett type swim tunnel, we found a significant effect of fish size and season on red snapper critical swimming speeds. For fish ranging between 6 and 17 cm standard length, critical swimming speeds ranged from about 35–70 cm/s, depending upon season. However, critical swimming speeds did not differ between day and night. This was an important observation since the majority of shrimp trawling in the Gulf occurs at night. We constructed and tested in the laboratory, a Vortex Generating Bycatch Reduction Device (VGBRD) that may prove useful in the shrimp trawl fishery. During behavioral tests during daylight, 79.2% of red snapper exited the VGBRD in an average of 4.1 min. However, during night-time tests, only 17.6% of red snapper exited the VGBRD in an average of 5.0 min. Behavioral tests revealed a strong negative phototactic response in dark adapted red snapper. We found that, during night-time tests when the VGBRD was illuminated with LED lights placed downstream of the exit, 96% of red snapper exited the device in 7.1 min. In color/ contrast choice experiments, red snapper unerringly associated with the dark colored (black or dark green) panel placed on the bottom of the experimental tank. In another set of experiments, we found that snapper displayed a strong optomotor response, i.e. the tendency to following and match speeds with a moving pattern. Illumination, color/contrast, and/or the optomotor response may improve bycatch reduction device performance.
3
McMichael, Anthony. "A Restless Climate." In Climate Change and the Health of Nations. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190262952.003.0007.
Full textAbstract:
Instructions Accompanying New Domestic devices are tedious. So, uninstructed, we plunge into assembling the device … and the likely result is all too familiar. By analogy, a basic understanding of the climate system and the forces influencing it will shed more light on later chapters. The climate system has many interacting parts, encompassing the linkages between atmosphere, oceans, land, and ice surfaces. The atmosphere and oceans are the prime global distributors of that part of incoming solar energy that Earth retains in the form of heat, much of which is then re- expressed as water vapor, wind, and ocean currents. As part of the Earth system, the world’s climate is always changing. The internal dynamics of the climate system are complex and regionally distinctive, and include, on shorter time scales, chaotic behavior. Meanwhile, larger forces are at work. As continents coalesce and then drift apart; as massive mountain ranges get pressed skyward; as Earth’s elliptical orbit around the sun alternates between greater and lesser rotundity; as both the tilt and wobble of the planet’s axis vary; as solar sunspots come and go; as fluctuations occur in the great ocean- based regional climatic cycles (the Pacific’s El Niño Southern Oscillation, the Indian Ocean Dipole Oscillation, the North Atlantic Inter- Decadal Oscillation, and others); and as volcanic eruptions enshroud the lower atmosphere— so the world’s climate varies on time- scales ranging from tens of millions of years to just several years. The main engine of the climate system, the atmosphere, is made up of many local circulation subsystems, often interacting with (or “coupled” with) the oceans. At a regional scale, different combinations of local circulation systems account for changes in climate, such as the decline in rainfall in Mesopotamia during the third millennium B.C.E., or the southward encroachment of the Arctic polar vortex that imposed the Big Freeze on much of the north eastern USA in the 2013– 2014 winter.
Conference papers on the topic "Rankin Vortex"
1
Bretschneider, Charles L., and Jen-Men Lo. "A Rankin Vortex Number as a Guide to the Selection of a Model Hurricane." In 19th International Conference on Coastal Engineering. New York, NY: American Society of Civil Engineers, 1985. http://dx.doi.org/10.1061/9780872624382.011.
Full text
2
Govaere, G., R. Silva, E. Mendoza, and E. Martinez. "Oceanographic Data for the Design of Maritime Structures Under Cyclone Conditions in the Bay of Campeche, Mexico." In ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37165.
Full textAbstract:
In this paper we present a methodology for the evaluation of significant wave heights, significant wave periods, maximum winds and minimum pressures using a modification of the original Hydromet-Rankin Vortex Model, Bretchneider (1990) and Holland (1980). The cyclone model is compared to the data series of 29 cyclones recorded by NOAA National Data Buoy Center bouys. Both models present very good results. For the analysis, the database uses 53 years of records, 541 hurricanes on the Atlantic Ocean. For the extreme analyses of wind and wave heights on the Mexican coasts, maps of the location and scale parameters used in the Gumbel cumulative distribution function and numerical results for 50 and 100 years return period are provided.
3
Swartzlander, Grover A. "Optical Rankine Vortex." In Frontiers in Optics. Washington, D.C.: OSA, 2005. http://dx.doi.org/10.1364/fio.2005.ftho6.
Full text
4
Belyaev, Ivan, and Victor Kopiev. "On sound scattering by a Rankine vortex." In 13th AIAA/CEAS Aeroacoustics Conference (28th AIAA Aeroacoustics Conference). Reston, Virigina: American Institute of Aeronautics and Astronautics, 2007. http://dx.doi.org/10.2514/6.2007-3421.
Full text
5
Wang, Xiaokun, Sinuo Liu, Xiaojuan Ban, Yanrui Xu, Jing Zhou, and Jiri Kosinka. "Robust turbulence simulation for particle-based fluids using the Rankine vortex model." In 2020 IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VRW). IEEE, 2020. http://dx.doi.org/10.1109/vrw50115.2020.00179.
Full text
6
Reddy, V. R. K., and Harish N. Dixit. "STABILITY ANALYSIS OF A RANKINE VORTEX WITH RADIAL DENSITY STRATIFICATION IN THREE DIMENSIONS." In Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2017). Connecticut: Begellhouse, 2018. http://dx.doi.org/10.1615/ihmtc-2017.120.
Full text
7
Ellis, M., C. Kurwitz, and F. Best. "Development of a Unique, Passive, Microgravity Vortex Separator." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81616.
Full textAbstract:
In the microgravity environment experienced by space vehicles, liquid and gas do not naturally separate as on Earth. This behavior presents a problem for two-phase space systems, such as environment conditioning, waste water processing, and power systems. Furthermore, with recent renewed interest in space nuclear power systems, a microgravity Rankine cycle is attractive for thermal to electric energy conversion and would require a phase separation device. Responding to this need, researchers have conceived various methods of producing phase separation in low gravity environments. These separator types have included wicking, elbow, hydrophobic/hydrophilic, vortex, rotary fan separators, and combinations thereof. Each class of separator achieved acceptable performance for particular applications and most performed in some capacity for the space program. However, increased integration of multiphase systems requires a separator design adaptable to a variety of system operating conditions. To this end, researchers at Texas A&M University (TAMU) have developed a Microgravity Vortex Separator (MVS) capable of handling both a wide range of inlet conditions as well as changes in these conditions with a single, passive design. Currently, rotary separators are recognized as the most versatile microgravity separation technology. However, compared with passive designs, rotary separators suffer from higher power consumption, more complicated mechanical design, and higher maintenance requirements than passive separators. Furthermore, research completed over the past decade has shown the MVS more resistant to inlet flow variations and versatile in application. Most investigations were conducted as part of system integration experiments including, among others, propellant transfer, waste water processing, and fuel cell systems. Testing involved determination of hydrodynamic conditions relating to vortex stability, inlet quality effects, accumulation volume potential, and dynamic volume monitoring. In most cases, a 1.2 liter separator was found to accommodate system flow conditions. This size produced reliable phase separation for liquid flow rates from 1.8 to 9.8 liters per minute, for gas flow rates of 0.5 to 180 standard liters per minute, over the full range of quality, and with fluid inventory changes up to 0.35 liters. Moreover, an acoustic sensor, integrated into the wall of the separation chamber, allows liquid film thickness monitoring with an accuracy of 0.1 inches. Currently, application of the MVS is being extended to cabin air dehumidification and a Rankine power cycle system. Both of these projects will allow further development of the TAMU separator.
8
Refan, Maryam, Horia Hangan, and Kamran Siddiqui. "Particle Image Velocimetry Measurements of Tornado-Like Flow Field in Model WindEEE Dome." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-22052.
Full textAbstract:
The flow field of tornado vortices simulated in the 1/11 scaled model of the Wind Engineering, Energy and Environment (WindEEE) Dome is characterized. Particle Image Velocimetry measurements were performed to investigate the flow dynamics for a wide range of Swirl ratios (0.12≤S≤1.29) and at various heights above the surface. It is shown that this simulator is capable of generating a wide variety of tornado like vortices ranging from a single-celled laminar vortex to a multi-celled turbulent vortex. Radial profiles of the tangential velocity demonstrated a clear variation in the experimental values with height at and after the touch-down of the breakdown bubble. Also, the comparison between experimental tangential velocities and the Rankine model estimations resulted in good agreement at only the upper levels (Z>0.35). Radial velocity values close to the surface rose as the swirl increased which is mainly due to the intensified tangential velocities in that region. In addition, variation of the radial velocity with height is more noticeable for higher swirls which can be explained by the flow regime being fully turbulent for S≥ 0.57.
9
Chien, Min-Hsiu, Nesrin Ozalp, and Gerald Morrison. "CFD and Heat Transfer Analysis of Vortex Formation in a Solar Reactor." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-22012.
Full textAbstract:
A hydrogen producing solar reactor was experimentally tested to study the cyclone flow dynamics of the gas-particle two-phase phenomenon. Two dimensional PIV (particle image velocimetry) was used to observe the flow and to quantify the vortex formation inside the solar reactor. The vortex flow structure in the reactor was reconstructed by capturing images from orientations perpendicular and parallel to the geometrical axis of the reactor respectively. The experimental results showed that the tangential components of the fluid velocity formed a Rankine-vortex profile. The free vortex portions of the Rankine profile were synchronized and independent of the axial position. The axial components showed a vortex funnel of higher speed fluid supplied by a reversing secondary flow. According to the inlet channel design, the geometry dominates the flow dynamics. A stable precessing vortex line was observed. As the vortex flow evolves towards the exit, the vortex funnel expands radially with decreasing tangential velocity magnitude peak as a result of the vortex stretching. An optimal residence time of the flow was found by changing the cyclone flow inlet conditions. The swirl number versus the main flow rate change was obtained. Upon the completion of the experimental studies, a thorough numerical analysis was conducted to model the flow dynamics inside the solar reactor and to verify the results by comparison to the experimental results. Three turbulence models including the standard k-ε, k-ε RNG and Reynolds Stress Transport models were used. CFD simulations were coupled with heat transfer analysis via Discrete Ordinate model. Particle tracing in Lagrange frame was applied to simulate the particle trajectory. A comparison between the turbulence modeling results for the room temperature and high temperature cases, as well as the experimental results for room temperature cases is presented.
10
Kang, Zhuang, Weixing Liu, and Wei Qin. "Vortex-Induced Vibration Experiment Research of Two Cylinders in Tandem Arrangement." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10471.
Full textAbstract:
The vortex-induced vibration of tandem arrangement of two cylinders compared with the single cylinder is more complicated, The double cylinder arranged in tandem, which is free to move in two degrees of freedom respectively, and which has low mass and damping. The present study shows that a critical centre-to-centre spacing can be used to distinguish the far and near wake interference. The streams in this test were uniform flow, ranging from 0.2m/s to 0.8m/s with the interval of 0.1m/s. The Re numbers are ranging from 22000 to 88000. The mass ratio of cylinder is low. For far wake interference, the downstream cylinder shows large amplitudes of response, therefore the wake induced vibration (WIV) is found. For near wake interference, both the upstream cylinder and downstream cylinder are exposed to an evident phenomenon of VIV, but the amplitude of upstream and downstream are less than that of single cylinders in cross-flow direction and in-line direction. We found the critical spacing to be 3.4 to 4.9.