Search results for "hydrodynamic"
showing 10 items of 530 documents
Modelling of the hydrodynamics of concurrent gas and liquid flow through packed bed
2016
The aim of the present study is to simulate concurrent gas and liquid flow through packed bed in the gas continuous flow regime (GCF) and continuity shock waves regime (CSW) using computational fluid dynamics (CFD). The application of multiple gas-liquid-solid model requires the knowledge of relationships determining interactions between phases. The exchange coefficients of these forces were defined by means of equations suggested by ATTOU et al. (1999). As a result of the computational simulation the following data were obtained: gas pressure drop in the bed, volume fraction distribution of a given phase (liquid and gas holdups) along the packing and its mean value in the reactor. The comp…
Numerical relativity simulations of tilted black hole-torus systems
2016
Las fusiones de objetos compactos se encuentran entre los eventos más interesantes de la astrofísica relativista, siendo, en particular, el principal objetivo de la astronomía de ondas gravitatorias. En esta tesis investigamos los posibles estados finales de la fusión de sistemas binarios formados por agujero negro-estrella de neutrones o por dos estrellas de neutrones: discos gruesos (o toros) de acrecimiento alrededor de agujeros negros en rotación tipo Kerr. Estos sistemas agujero negro-toro se cree que constituyen el motor central de los eventos más luminosos del Universo: los llamados estallidos de rayos gamma. Nuestro conocimiento sobre la evolución y la estabilidad de estos sistemas …
Analytical solutions of magnetohydrodynamical problems on a flow of conducting fluid in the entrance region of channels in a strong magnetic field šķ…
2014
Darbā iegūti analītiskie atrisinājumi magnetohidrodinamiskiem (MHD) uzdevumiem par elektrovadoša šķidruma plūsmu plakanā un cilindriskā kanālā stiprā magnētiskā laukā gadījumiem, kad šķidrums ietek kanālos caur galīga platuma spraugu vai caur galīga rādiusa atveri kanāla sānu malā. Pamatojoties uz iegūtajiem atrisinājumiem, veikta plūsmas ātruma lauka skaitliskā analīze. Iegūti uzdevumu asimptotiskie atrisinājumi lieliem Hartmana skaitļiem. Turklāt darbā pētīta pilna spiediena spēka šķidruma ieplūdes apgabalā atkarība no funkcijas veida, ar kuru ir uzdots ātruma robežnosacījums. Pētījums veikts analītiski, risinot divas hidrodinamiskas problēmas un divas MHD problēmas par viskoza šķidruma i…
Extracting qˆ in event-by-event hydrodynamics and the centrality/energy puzzle
2017
In our analysis, we combine event-by-event hydrodynamics, within the EKRT formulation, with jet quenching -ASW Quenching Weights- to obtain high- for charged particles at RHIC and LHC energies for different centralities. By defining a K-factor that quantifies the departure of from an ideal estimate, , we fit the single-inclusive experimental data for charged particles. This K-factor is larger at RHIC than at the LHC but, surprisingly, it is almost independent of the centrality of the collision. peerReviewed
A GENERAL COMPUTATIONAL APPROACH FOR MAGNETOHYDRODYNAMIC FLOWS USING THE CFX CODE: BUOYANT FLOW THROUGH A VERTICAL SQUARE CHANNEL
2000
The buoyancy-driven magnetoconvection in the cross section of an infinitely long vertical square duct is investigated numerically using the CFX code package. The implementation of a magnetohydrodynamic (MHD) problem in CFX is discussed, with particular reference to the Lorentz forces and the electric potential boundary conditions for arbitrary electrical conductivity of the walls. The method proposed is general and applies to arbitrary geometries with an arbitrary orientation of the magnetic field. Results for fully developed flow under various thermal boundary conditions are compared with asymptotic analytical solutions. The comparison shows that the asymptotic analysis is confirmed for hi…
SPH modeling of blood flow in cerebral aneurysms
Gli aneurismi cerebrali sono dilatazioni patologiche di arterie cerebrali. Queste patologie hanno un intrinseco rischio di rottura con conseguenti emorragie intracraniche. Sebbene i meccanismi di formazione, crescita e rottura degli aneurismi cerebrali non sono ancora del tutto compresi, è comunemente riconosciuto che in questi processi i fattori emodinamici giocano un ruolo molto importante. Le simulazioni numeriche possono fornire utili informazioni sull'emodinamica e possono essere usate per applicazioni cliniche. Nei tradizionali metodi numerici basati su una griglia di calcolo il processo di discretizzazione dei vasi cerebrali sui quali insiste un aneurisma è molto complesso. D’altra p…
Letter to the Editor. The missing piece to solve the equation.
2020
Numerical treatment of radiation processes in the internal shocks of magnetized relativistic outflows
2017
Los blázares son un tipo de núcleo activo de galaxia (AGN, por sus siglas en inglés) que se encuentran entre los objetos astrofísicos más energéticos y violentos, a la par de los brotes de rayos gamma (GRB por sus siglas en inglés). Los procesos físicos y, en particular, el escenario del chorro relativista en el que se genera la radiación ultraenergética detectada por observatorios terrestres y en órbita, han conseguido atraer la atención e interés de los astrónomos y astrofísicos desde su descubrimiento. En la presente tesis investigamos el modelo de choques internos (IS) cuya hipótesis consta del choque de dos capas de plasma con geometría cilíndrica, formando dos ondas de choque que atra…
Enhancing the Iterative Smoothed Particle Hydrodynamics Method
2021
Motivated by recent research on the iterative approach proposed for the smoothed particle hydrodynamics (ISPH) method, some ideas to improve the process are introduced. The standard procedure is enhanced iterating on the residuals preserving the matrix-free nature of the process. The method is appealing providing reasonable results with disordered data distribution too and no kernel variations are needed in the approximation. This work moves forward with a novel formulation requiring a lower number of iterations to reach a desired accuracy. The computational procedure is described and some results are introduced to appreciate the proposed formulation.