Exploració per autor "Oliva Llena, Asensio"
Ara es mostren els items 60-79 de 343
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Can we hit the ultimate regime of thermal turbulence using LES simulations at low Prandtl numbers?
Trias Miquel, Francesc Xavier; Gorobets, Andrey; Oliva Llena, Asensio (Begell House, 2023)
Text en actes de congrés
Accés restringit per política de l'editorialIn this work, we aim to shed light on the following research question: can we hit the ultimate regime of thermal turbulence using large-eddy simulations (LES) at low Prandtl numbers? This is motivated by our recent findings ... -
CFD simulation of the thermal behavior of a wind mill power generator nacelle
Colomer Rey, Guillem; Lehmkuhl Barba, Oriol; Borrell Pol, Ricard; Oliva Llena, Asensio (2009)
Comunicació de congrés
Accés restringit per política de l'editorialIn this work we use the Large Eddy Simulation model to predict the thermal behavior of the air inside of a wind generator nacelle, where several elements with di erent thermal characteristics are found. Outside air enters ... -
Characteristics of the near wake region behind a cylinder at critical and super-critical Reynolds numbers
Rodríguez Pérez, Ivette María; Lehmkuhl Barba, Oriol; Chiva Segura, Jorge; Borrell Pol, Ricard; Oliva Llena, Asensio (Begell House, 2015)
Text en actes de congrés
Accés restringit per política de l'editorialLarge-eddy simulations (LES) of the flow past a circular cylinder are used to investigate the characteristics of the near wake region at Reynolds numbers Re = 2.5 × 105 - 8.5 × 105. This range encompasses both the critical ... -
Coherent structures in a flow past a circular cylinder at critical and super-critical Reynolds numbers
Rodríguez Pérez, Ivette María; Lehmkuhl Barba, Oriol; Chiva Segura, Jorge; Borrell Pol, Ricard; Oliva Llena, Asensio (Springer, 2015)
Text en actes de congrés
Accés restringit per política de l'editorialIt is well known that the wake topology in the flow past a circular cylinder remains almost unchanged up to Reynolds number ~105 Williamson (Annu Rev Fluid Mech 28(1), 477–539 (1996)) [1]. Then, at Re~2×105 major changes ... -
Combined heat and moisture transfer in buildings systems
Damle, Rashmin; Lehmkuhl Barba, Oriol; Rigola Serrano, Joaquim; Oliva Llena, Asensio (2012)
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Accés restringit per política de l'editorialTemperature and humidity are the two main parameters indicating the comfort level of the building occupants. Although the effect of temperature is taken into account in thermal simulation of buildings, the moisture transfer ... -
Comparative study of subfilter scalar dissipation rate and mixture fraction variance models
Ventosa Molina, Jordi; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Muela Castro, Jordi; Oliva Llena, Asensio (2014)
Text en actes de congrés
Accés restringit per política de l'editorialAccurate characterisation of mixing at the subfilter level is a critical aspect in many LES combustion models, such as flamelet based and Conditional Moment Closure models. Several models can be found in the literature, ... -
Comparison of the performance of falling film and bubble absorbers for air-cooled absorption systems
Castro González, Jesús; Oliet Casasayas, Carles; Rodríguez Pérez, Ivette María; Oliva Llena, Asensio (2009-07-01)
Article
Accés obertSmall capacity, air-cooled NH3–H2O absorption systems are becoming more attractive in applications where the input energy can be obtained for free (e.g., solar energy, exhaust gases of engines, etc.), due to the increasing ... -
Compressible 1D-3D simulation of a muffler with pseudosound prediction levels
López Mas, Joan; Ruano Pérez, Jesús; Lehmkuhl Barba, Oriol; Rigola Serrano, Joaquim; Oliva Llena, Asensio (International Institute of Refrigeration, 2015)
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Accés restringit per política de l'editorialNumerical software for the simulation of thermal and fluid-dynamic behavior of hermetic reciprocating compressors is a must for its understanding and improvement. Hence, these tools are widely used to improve ... -
Computational investigation of the hexagonal honeycomb adsorption reactor for cooling applications: Honeycomb adsorption reactor for cooling
Papakokkinos, Giorgos; Castro González, Jesús; Oliet Casasayas, Carles; Oliva Llena, Asensio (2022-02-05)
Article
Accés obertAdsorption cooling is a sustainable technology, since it can utilize solar energy or waste heat, while employing substances without ozone depletion and global warming potential. The adsorption reactor design is determinant ... -
Conservative discretization of multiphase flow with high density ratios
Jofre Cruanyes, Lluís; Lehmkuhl Barba, Oriol; Balcázar Arciniega, Néstor; Castro González, Jesús; Rigola Serrano, Joaquim; Oliva Llena, Asensio (WIT Press, 2014)
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Accés obertThe computation of multiphase flows presenting high density ratios, where the fluids involved are considered immiscible, are of great importance for fundamental physics and industrial applications; such as the study of ... -
Control strategy approach based on the operational results of a small capacity direct air -cooled LiBr -Water absorption chiller
Farnós Baulenas, Joan; Castro González, Jesús; Papakokkinos, Giorgos; Oliva Llena, Asensio (International Solar Energy Society, 2017)
Comunicació de congrés
Accés obertThe scope of this paper is to give a short overview of the state of the art regarding control strategies, identify the role of different operating conditions, and provide useful suggestions for the design and operation of ... -
Cost-vs-accuracy analysis of self-adaptive time-integration methods
Plana Riu, Josep; Trias Miquel, Francesc Xavier; Pérez Segarra, Carlos David; Oliva Llena, Asensio (Begell House, 2023)
Text en actes de congrés
Accés restringit per política de l'editorialThe integration in time of the semi-discrete Navier-Stokes equations has been historically bounded by the classic CFL condition, and later on, an innovative method has been defined by ensuring the eigenvalues of the method ... -
Coupled radiation and natural convection: Different approaches of the slw model for a non-gray gas mixture
Colomer Rey, Guillem; Consul Serracanta, Ricard; Oliva Llena, Asensio (2007-09)
Article
Accés obertThe coupling between non-gray radiation heat transfer and convection–conduction heat transfer is studied. The spectral line weighted sum of gray gases model (SLW) is used to account for non-gray radiation properties. The ... -
Coupling CFD models of airflow with building simulation with an object-oriented and parallel infrastructure
Damle, Rashmin; Lehmkuhl Barba, Oriol; Rodríguez Pérez, Ivette María; Oliva Llena, Asensio (2012)
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Accés restringit per política de l'editorialIntegrating CFD & HT models with the general building program raises the computational time of building simulations as these simulations are usually performed over a period of one year. Within this context, our aim is ... -
Data-driven prediction of flow parameters in a ventilated cavity using high-fidelity CFD simulations
Morozova, Nina; Trias Miquel, Francesc Xavier; Capdevila Paramio, Roser; Oliva Llena, Asensio (International Building Performance Simulation Association (IBPSA), 2021)
Text en actes de congrés
Accés restringit per política de l'editorialIn this study, we develop a machine-learning-based data-driven model, which predicts comfort-related flow parameters in a ventilated room. The model is based on the results of high-fidelity computational fluid dynamics ... -
Detailed analysis of fin-and-tube evaporators
Oliet Casasayas, Carles; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2009-09-17)
Comunicació de congrés
Accés restringit per política de l'editorialThis paper is devoted to the presentation of a new model for fin-and-tube evaporators, focusing on the solid core simulation and its integration with a quasi-homogeneous two-phase flow model for the in-tube refrigerant ... -
Detailed numerical model for the receiver of a solar power tower plant
Chiva Segura, Jorge; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio (2012)
Memòria / Número de revista
Accés restringit per política de l'editorialIn this paper, a numerical model for the simulation of the receiver of a solar power tower plant is presented. This global model is composed of 4 specific sub-models (heat conduction, two-phase, thermal radiation and natural ... -
Detailed numerical model for the resolution of molten salt storage tanks for CSP plants
Pérez Segarra, Carlos David; Rodríguez Pérez, Ivette María; Oliva Llena, Asensio; Torras Ortíz, Santiago; Lehmkuhl Barba, Oriol (2012)
Text en actes de congrés
Accés obertConsidering the state-of-the-art in TES technologies, two-tank indirect system using molten salt is the most widespread within CSP plants. However, current techniques for design and optimization, as well as, for assessing ... -
Detailed numerical study of turbulent flows in air curtains
Jaramillo Ibarra, Julian Ernesto; Pérez Segarra, Carlos David; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio (2010)
Comunicació de congrés
Accés restringit per política de l'editorialAir curtains are generally a set of vertical or horizontal plane jets used as ambient separator. In order to prevent entrainment, a good air curtain should provide a jet with low turbulence level, enough momentum to ... -
Detailed prediction of fluid-solid coupled phenomena of turbulent flow through reed valves
González Acedo, Ignacio; Naseri, Alireza; Rigola Serrano, Joaquim; Pérez Segarra, Carlos David; Oliva Llena, Asensio (Institute of Physics (IOP), 2019)
Text en actes de congrés
Accés obertThe operation of self-actuated valves in suction and discharge processes plays a crucial role in the thermal efficiency and structural reliability of hermetic reciprocating compressors. The present work provides a thorough ...