The Experts below are selected from a list of 87 Experts worldwide ranked by ideXlab platform
Azeddine Kourta - One of the best experts on this subject based on the ideXlab platform.
-
Separation flow control on a generic ground vehicle using steady microjet arrays
Experiments in Fluids, 2011Co-Authors: Sandrine Aubrun, Farrukh Alvi, Jonathan Mcnally, Azeddine KourtaAbstract:A model of a generic vehicle shape, the Ahmed body with a 25° slant, is equipped with an array of blowing steady microjets 6 mm downstream of the separation line between the roof and the slanted Rear Window. The goal of the present study is to evaluate the effectiveness of this actuation method in reducing the aerodynamic drag, by reducing or suppressing the 3D closed separation bubble located on the slanted surface. The efficiency of this control approach is quantified with the help of aerodynamic load measurements. The changes in the flow field when control is applied are examined using PIV and wall pressure measurements and skin friction visualisations. By activating the steady microjet array, the drag coefficient was reduced by 9–14% and the lift coefficient up to 42%, depending on the Reynolds number. The strong modification of the flow topology under progressive flow control is particularly studied.
-
drag reduction by flow separation control on a car after body
International Journal for Numerical Methods in Fluids, 2009Co-Authors: Mathieu Roumeas, Patrick Gillieron, Azeddine KourtaAbstract:New development constraints prompted by new pollutant emissions and fuel consumption standards (Corporate Average Economy Fuel) require that automobile manufacturers develop new flow control devices capable of reducing the aerodynamic drag of motor vehicles. The solutions envisaged must have a negligible impact on the vehicle geometry. In this context, flow control by continuous suction is seen as a promising alternative. The control configurations identified during a previous 2D numerical analysis are adapted for this purpose and are tested on a 3D geometry. A local suction system located on the upper part of the Rear Window is capable of eliminating the Rear Window separation on simplified fastback car geometry. Aerodynamic drag reductions close to 17% have been obtained.
-
separated flows around the Rear Window of a simplified car geometry
Journal of Fluids Engineering-transactions of The Asme, 2008Co-Authors: Mathieu Roumeas, Patrick Gillieron, Azeddine KourtaAbstract:A 3D numerical simulation based on the lattice Boltzmann method is carried out on a simplified car geometry (initially proposed by Ahmed, Ramm, and Falting, 1984, SAE Technical Paper series No. 840300) to analyze and establish a method for controlling the near-wake flow topology of a generic blunt body model. The results indicate the existence of a complex flow topology consisting of transverse and longitudinal vortices emanating from flow separations that occur on the top and the lateral edges of the slanted Rear Window, respectively. The topology of each structure is detailed and the numerical results are compared with the experimental results in the literature. The results presented in this paper can then be used to develop and parametrize active control solutions conducive to improving the aerodynamic performances of automobile vehicles.
Patrick Gillieron - One of the best experts on this subject based on the ideXlab platform.
-
active procedures to control the flow past the ahmed body with a 25 Rear Window
International Journal of Aerodynamics, 2011Co-Authors: Charleshenri Bruneau, Emmanuel Creuse, Delphine Depeyras, Patrick Gillieron, Iraj MortazaviAbstract:Ahmed body with a 25 degree Rear Window is used to represent a simpli ed car geometry. Two and three-dimensional simulations are performed to analyse the flow behaviour around such a vehicle. Sucking and blowing jets or slots are added on the body to control the flow. The results presented show that good drag reductions are achieved for a good choice of the active procedure.
-
Bluff-body drag reduction using a deflector
Experiments in Fluids, 2011Co-Authors: Patrick Gillieron, Grégoire Fourrié, Labraga Larbi, Keirsbulck LaurentAbstract:A passive flow control on a generic car model was experimentally studied. This control consists of a deflector placed on the upper edge of the model Rear Window. The study was carried out in a wind tunnel at Reynolds numbers based on the model height of 3.1 x 105 and 7.7 x 105. The flow was investigated via standard and stereoscopic particle image velocimetry, Kiel pressure probes and surface flow visualization. The aerodynamic drag was measured using an external balance and calculated using a wake survey method. Drag reductions up to 9% were obtained depending on the deflector angle. The deflector increases the separated region on the Rear Window. The results show that when this separated region is wide enough,it disrupts the development of the counter-rotating longitudinal vortices appearing on the lateral edges of the Rear Window. The current study suggests that flowcontrol on such geometries should consider all the flow structures that contribute to the model wake flow.
-
drag reduction by flow separation control on a car after body
International Journal for Numerical Methods in Fluids, 2009Co-Authors: Mathieu Roumeas, Patrick Gillieron, Azeddine KourtaAbstract:New development constraints prompted by new pollutant emissions and fuel consumption standards (Corporate Average Economy Fuel) require that automobile manufacturers develop new flow control devices capable of reducing the aerodynamic drag of motor vehicles. The solutions envisaged must have a negligible impact on the vehicle geometry. In this context, flow control by continuous suction is seen as a promising alternative. The control configurations identified during a previous 2D numerical analysis are adapted for this purpose and are tested on a 3D geometry. A local suction system located on the upper part of the Rear Window is capable of eliminating the Rear Window separation on simplified fastback car geometry. Aerodynamic drag reductions close to 17% have been obtained.
-
separated flows around the Rear Window of a simplified car geometry
Journal of Fluids Engineering-transactions of The Asme, 2008Co-Authors: Mathieu Roumeas, Patrick Gillieron, Azeddine KourtaAbstract:A 3D numerical simulation based on the lattice Boltzmann method is carried out on a simplified car geometry (initially proposed by Ahmed, Ramm, and Falting, 1984, SAE Technical Paper series No. 840300) to analyze and establish a method for controlling the near-wake flow topology of a generic blunt body model. The results indicate the existence of a complex flow topology consisting of transverse and longitudinal vortices emanating from flow separations that occur on the top and the lateral edges of the slanted Rear Window, respectively. The topology of each structure is detailed and the numerical results are compared with the experimental results in the literature. The results presented in this paper can then be used to develop and parametrize active control solutions conducive to improving the aerodynamic performances of automobile vehicles.
Mathieu Roumeas - One of the best experts on this subject based on the ideXlab platform.
-
drag reduction by flow separation control on a car after body
International Journal for Numerical Methods in Fluids, 2009Co-Authors: Mathieu Roumeas, Patrick Gillieron, Azeddine KourtaAbstract:New development constraints prompted by new pollutant emissions and fuel consumption standards (Corporate Average Economy Fuel) require that automobile manufacturers develop new flow control devices capable of reducing the aerodynamic drag of motor vehicles. The solutions envisaged must have a negligible impact on the vehicle geometry. In this context, flow control by continuous suction is seen as a promising alternative. The control configurations identified during a previous 2D numerical analysis are adapted for this purpose and are tested on a 3D geometry. A local suction system located on the upper part of the Rear Window is capable of eliminating the Rear Window separation on simplified fastback car geometry. Aerodynamic drag reductions close to 17% have been obtained.
-
separated flows around the Rear Window of a simplified car geometry
Journal of Fluids Engineering-transactions of The Asme, 2008Co-Authors: Mathieu Roumeas, Patrick Gillieron, Azeddine KourtaAbstract:A 3D numerical simulation based on the lattice Boltzmann method is carried out on a simplified car geometry (initially proposed by Ahmed, Ramm, and Falting, 1984, SAE Technical Paper series No. 840300) to analyze and establish a method for controlling the near-wake flow topology of a generic blunt body model. The results indicate the existence of a complex flow topology consisting of transverse and longitudinal vortices emanating from flow separations that occur on the top and the lateral edges of the slanted Rear Window, respectively. The topology of each structure is detailed and the numerical results are compared with the experimental results in the literature. The results presented in this paper can then be used to develop and parametrize active control solutions conducive to improving the aerodynamic performances of automobile vehicles.
Pozo Alemán Patricia - One of the best experts on this subject based on the ideXlab platform.
-
La habitación en el cine : el reflejo de emociones y personalidad en la puesta en escena de la arquitectura
'Universidad Politecnica de Madrid - University Library', 2017Co-Authors: Pozo Alemán PatriciaAbstract:El interés del trabajo radica en encontrar el punto de encuentro entre emociones, arquitectura y cine. En arquitectura las emociones que se quieren expresar/provocar, normalmente, son siempre positivas. Sin embargo, encontramos emociones positivas y negativas en dos campos concretos de la arquitectura: el primero es la escultura edificatoria, y el segundo es la arquitectura para el cine. La escultura edificatoria es capaz de expresar literalmente las emociones, de dibujarlas sobre la arquitectura. La arquitectura para el cine se encarga de potenciar una serie de emociones a través de distintos parámetros como la luz, el color, las dimensiones, los materiales, las texturas, el estilo, y demás; todo acorde con el lenguaje cinematográfico, en una abstracción de las emociones directas. De este modo, las emociones se expresan directamente, de un modo literal, a través de la piel de la escultura edificatoria (el edificio), y posteriormente, a través de la arquitectura para el cine, indirectamente, de un modo abstracto. Se estudia la relación entre antropología y arquitectura: de qué manera la piel de la persona (primera piel), es la que diferencia el interior del exterior; la ropa constituye la segunda piel, y la arquitectura la tercera piel. Este discurso antropológico de secuencia de pieles, se lleva al cine a través de la arquitectura como transmisora de las emociones que experimenta la piel de una forma patológica. De piel humana a piel arquitectónica. De este modo se reproducen las emociones en la arquitectura. Películas como Repulsión y Barton Fink, materializan visualmente esta traslación. Esto ocurre porque se crean conexiones entre la mente y la arquitectura. Estas conexiones se muestran visualmente en el cine. Traumas, patologías, sentidos, deseo, terror, memoria, sueños. Todas las conexiones posibles. De la visión introspectiva, se pasa a la extrospectiva. Mirar hacia afuera. La atención se centra en el enlace de la habitación con el exterior, es decir, la ventana. Con películas como La ventana indiscreta, La larga noche del 43’, La ventana, Una habitación con vistas. La idea es analizar qué se ve desde el interior: una ciudad, un callejón, la ventana de enfrente, el campo, el mar...y si estas vistas influyen de algún modo en la personalidad del protagonista, en sus emociones, o en sus estados de ánimo. Por otra parte, profundizando en el tema de las emociones, encontramos un tema fascinante: la personalidad. Considerando la habitación como la unidad más íntima en arquitectura, surge el estudio de la habitación como reflejo de la personalidad de un individuo y sus emociones, a través de la arquitectura para el cine. Este análisis confirma la repetición de una serie de parámetros arquitectónicos asociados a determinados rasgos de la personalidad humana. Laura, Pickpocket, Taxi Driver. La lista de 42 películas seleccionadas abarca cine de los años veinte, hasta la actualidad, pasando por todas las décadas, y presentando distintos tipos de cine, cultura, etc., para conseguir una visión general. Un experimento científico llevado a cabo en distintas universidades, corrobora la relación que se crea entre arquitectura para el cine y emociones. Se confirma la reacción emocional más intensa ante la secuencia, respecto al fotograma. Y la mayor sensibilidad de los arquitectos ante la composición espacial mostrada en una imagen. En resumen, se trata de explicar de qué forma el cine muestra un interior arquitectónico determinado, buscando reflejar y/o potenciar la personalidad de un individuo, sus emociones, o sus estados de ánimo. También se podría completar con las emociones provocadas en el espectador a través de determinadas tipologías arquitectónicas desde el exterior: estilos, formas, dimensiones, colores, luces, entorno; siempre con la particular atmósfera que crea el cine con sus encuadres, planos, y cambios de movimiento/tiempo. ----------ABSTRACT---------- The goal of this project lies in finding the point of convergence among emotions, architecture and cinema. The type of emotions that architecture wants to express is almost always positive. Nevertheless, we find both positive and negative emotions in two particular fields of architecture: the first one is architectonic sculpture, and the second one is architecture for the cinema. Architectonic sculpture is able to literally express emotions, to engrave them on the architecture. Architecture for the cinema attempts to evoke a series of emotions through different parameters like light, color, dimensions, materials, textures, and style; all in accordance with cinematographic language, in an abstraction of the direct emotions. Emotions are expressed directly, in a literal way, through the medium of the architectonic sculpture (the building), and indirectly, in an abstract way, through the medium of architecture for the cinema. The relation between anthropology and architecture will also be studied in this project by examining the different ‘skins’ a person has. The first skin is the one distinguishing the interior from the exterior; clothes constitute the second skin, and architecture the third skin. This anthropological discourse of the skin sequence carries over to the cinema through architecture as a transmitter of the emotions in which skins express emotions in a pathologic way. From human skin to architectural skin, emotions are reproduced in architecture for the cinema. Films like Repulsion and Barton Fink materialize this translation visually. This occurs because connections between the mind and architecture are created. These connections are then displayed visually in the cinema. Traumas, moods, senses, desire, terror, memory, dreams. From the introspective vision, the extrospective follows. Looking outside. With films like Rear Window, La lunga notte del 43’, The Window, A room with a view, the focus will be on the connection of the room with the exterior, in other words, the Window. The idea is to analyze what you can see from the interior (a city, an alley, the opposite Window, a country, the sea…) and if these views somehow influence the personality of the main character, his/her emotions, or his/her moods. Exploring the topic of emotions in depth, we find a fantastic theme: personality. Considering the room as the most intimate unit in architecture, the study of the room as a reflection of the personality of an individual and his/her emotions emerges through architecture for the cinema. This analysis confirms the repetition of a series of architectural parameters associated with certain features of the human personality. Laura, Pickpocket, Taxi Driver. The list of the 42 films selected contains cinema from the 20’s to the present, going through all the decades and presenting different types of cinema and culture, in order to get an overall impression. A scientific experiment carried out in different Spanish universities supports the hypothesis that there is a relation between architecture for the cinema and emotions. A more intense emotional reaction occurred when the subjects were exposed to scenes rather than photograms. Furthermore, architecture students confirmed their higher sensibility to the spatial composition shown in a picture when compared to students from other fields. To summarize, this project will explain the form in which the cinema shows a certain architectonic interior, seeking to reflect and/or empower the personality of an individual, his/her emotions, or his/her moods. It will also take into consideration the emotions provoked in the spectator through determinate architectural typologies from the exterior: styles, forms, dimensions, colors, lights, and environment; always in the particular atmosphere which cinema creates with its frames, shots, and changes of movement/time
Iraj Mortazavi - One of the best experts on this subject based on the ideXlab platform.
-
active procedures to control the flow past the ahmed body with a 25 Rear Window
International Journal of Aerodynamics, 2011Co-Authors: Charleshenri Bruneau, Emmanuel Creuse, Delphine Depeyras, Patrick Gillieron, Iraj MortazaviAbstract:Ahmed body with a 25 degree Rear Window is used to represent a simpli ed car geometry. Two and three-dimensional simulations are performed to analyse the flow behaviour around such a vehicle. Sucking and blowing jets or slots are added on the body to control the flow. The results presented show that good drag reductions are achieved for a good choice of the active procedure.
