The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Jean-robert Clermont - One of the best experts on this subject based on the ideXlab platform.
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Stream Tube method in three dimensional problems
2021Co-Authors: Jean-robert Clermont, Amine AmmarAbstract:In Chaps. 3 and 4, theory and applications of the Stream-Tube method are devoted to planar and axisymmetric cases, using one transformation function.
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Stream Tube method for unsteady flows
2021Co-Authors: Jean-robert Clermont, Amine AmmarAbstract:Stream-Tube Method (STM) concepts are considered in this chapter for studies of isothermal unsteady flows in two- and three-dimensional situations. Notably, the approach provides accurate formulae for evaluating the kinematic histories, required time-dependent constitutive equations. For example, such cases may be encountered in processing rheology and lubrication problems, requiring evaluation of strain or deformation rate tensors. Focusing on incompressible materials, this chapter extends the possibilities of STM to evaluate kinematic quantities in unsteady flows, where Streamlines and pathlines are not identical.
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Stream Tube method for thermal flows and solid mechanics
2021Co-Authors: Jean-robert Clermont, Amine AmmarAbstract:In this chapter, applications of Stream-Tube Method are proposed for non-isothermal flows. It is well known that temperature effects are of importance for industrial situations, notably in complex flows of polymers and manufacturing processes. The examples shown here are found to be interesting and useful enough to be considered now in two-dimensional flow configurations, for different temperature conditions. Examples are proposed for two fluids obeying Newtonian and viscoelastic memory-integral equations.
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micro macro simulations and Stream Tube method
2021Co-Authors: Jean-robert Clermont, Amine AmmarAbstract:Atomistic modelling is the most detailed level of description that can be applied today in rheological studies.
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Stream Tube method domain decomposition closed Streamlines
2021Co-Authors: Jean-robert Clermont, Amine AmmarAbstract:This chapter presents STM theoretical elements leading to computations in complex flow domains involving both straight and closed Streamlines, using a domain decomposition approach. Local transformation functions in two- or three-dimensional sub-domains may be defined to simulate flows of complex fluids as those requiring evaluation of particle time history.
M. Messina - One of the best experts on this subject based on the ideXlab platform.
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design of a vertical axis wind turbine how the aspect ratio affects the turbine s performance
international journal of energy and environmental engineering, 2014Co-Authors: S. Brusca, R. Lanzafame, M. MessinaAbstract:This work analyses the link between the aspect ratio of a vertical-axis straight-bladed (H-Rotor) wind turbine and its performance (power coefficient). The aspect ratio of this particular wind turbine is defined as the ratio between blade length and rotor radius. Since the aspect ratio variations of a vertical-axis wind turbine cause Reynolds number variations, any changes in the power coefficient can also be studied to derive how aspect ratio variations affect turbine performance. Using a calculation code based on the Multiple Stream Tube Model, symmetrical straight-bladed wind turbine performance was evaluated as aspect ratio varied. This numerical analysis highlighted how turbine performance is strongly influenced by the Reynolds number of the rotor blade. From a geometrical point of view, as aspect ratio falls, the Reynolds number rises which improves wind turbine performance.
Mats Sandberg - One of the best experts on this subject based on the ideXlab platform.
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power transportation inside Stream Tube of cross ventilated simple shaped model and pitched roof house
Building and Environment, 2009Co-Authors: Tomohiro Kobayashi, Kazunobu Sagara, Toshio Yamanaka, Hisashi Kotani, Mats SandbergAbstract:The ultimate goal of this work is to establish a prediction method based on Power Balance Model for prediction of flow rate through cross-ventilated building. For the establishment of Power Balance Model, the lost power across Stream Tube sections must be determined in advance. However, the loss of power in the Stream Tube was not well studied by other researchers but this concerned critical step forms the focus of the present CFD study in which transported power in Stream Tubes formed at two selected models: (i) a suspended rectangular model, and (ii) a pitched roof single-storey house model standing on a flat ground surface, was documented. For the development of a new method applying to predict the lost power, decrease of the transported power across the Stream Tubes through both types of models will finally be shown in this paper.
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Stream Tube based analysis of problems in prediction of cross ventilation rate
International Journal of Ventilation, 2009Co-Authors: Tomohiro Kobayashi, Kazunobu Sagara, Toshio Yamanaka, Hisashi Kotani, Shogo Takeda, Mats SandbergAbstract:The airflow rate of a building ventilated by wind is usually predicted by using the wind pressure coefficients obtained for a sealed building and discharge coefficients based on measuring the airfl ...
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Stream Tube analysis of cross ventilated simple shaped model and detached house
6th International Conference on Indoor Air Quality Ventilation and Energy Conservation in Buildings: Sustainable Built Environment IAQVEC 2007 28 Octo, 2007Co-Authors: Tomohiro Kobayashi, Kazunobu Sagara, Toshio Yamanaka, Hisashi Kotani, Mats SandbergAbstract:Conventional method to predict ventilation rate induced by wind is based on the orifice equation associated with the discharge coefficient and wind pressure coefficient. In the cross-ventilation phenomena, however, this method has a problem due to the difficulty to predict resistance of the building related with total pressure loss. In this paper, therefore, the Stream Tube caught by the inlet opening is analyzed to investigate the pressure loss due to the transformation (and possibly convergence and divergence) of the Stream Tube. Two types of model, simple-shaped rectangular model and detached house model, were analyzed with three cases of porosity by using CFD prediction. Flow fields inside and outside of the model are to be compared between two types of model. Besides, based on the Stream Tube analysis, cross-sectional area and average pressure inside the Stream Tube will be shown and compared between two types of model. For the detached house model, finally, static pressure inside the Stream Tube will be compared with that on the floor.
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wind driven flow through openings analysis of the Stream Tube
International Journal of Ventilation, 2006Co-Authors: Tomohiro Kobayashi, Kazunobu Sagara, Toshio Yamanaka, Hisashi Kotani, Mats SandbergAbstract:AbstractWind approaching a building provided with openings on the windward and leeward sides has a choice, either it flows through the openings or flows around and above the building. This choice gives rise to a dominant Stream Tube containing the fluid flowing through the openings. In this paper the Stream Tube is analysed based on wind tunnel measurements and CFD simulation. A house model with dimensions 120 mm (Width)×120 mm (Height)×180 mm (Length) was provided with rectangular openings of equal size located opposite each other. The end walls were thin giving rise to a sharp edged opening. The size of the openings expressed as the porosity (opening area divided by the facade area) was 1.3 %, 5.2 %, 11.6 %, 20.7 % and 46.5 %. In the wind tunnel, velocity including velocity fluctuations and pressure were measured along the centre line through the openings. In the CFD prediction it was possible to visualize the Stream Tube by the method of “flying particles”. This made it possible to explore the change i...
Xinwei Liao - One of the best experts on this subject based on the ideXlab platform.
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evaluation of co2 enhanced oil recovery and sequestration potential in low permeability reservoirs yanchang oilfield china
Journal of The Energy Institute, 2014Co-Authors: Dongfeng Zhao, Xinwei Liao, D D YinAbstract:Abstract Sequestrating CO 2 in reservoirs can substantially enhance oil recovery and effectively reduce greenhouse gas emission. To evaluate the potential of CO 2 enhanced oil recovery (EOR) and sequestration for Yanchang Oilfield in China, a screening standard which was suitable for CO 2 -EOR and sequestration in Yanchang Oilfield was proposed based on its characteristics of strong heterogeneity, high water content and severe fluid channeling after water flooding. In addition, an efficient calculation method – Stream Tube simulation method was presented to figure out CO 2 sequestration coefficient and oil recovery factor. After screening and evaluating, it turned out that 148 out of 176 blocks in 22 oilfields were suitable for CO 2 -EOR and sequestration. CO 2 flooding after water flooding can produce 180.21 × 10 6 t more crude oil and sequestrate 223.38 × 10 6 t CO 2 . The average incremental oil recovery rate of miscible reservoirs was 12.49% and the average CO 2 sequestration coefficient was 0.27 t/t while the two values were 6.83% and 0.18 t/t for immiscible reservoirs. There are comparatively more reservoirs that are suitable for CO 2 -EOR and sequestration in Yanchang Oilfield than normal, which can obviously enhance oil recovery and means a great potential for CO 2 sequestration. CO 2 -EOR and sequestration in Yanchang Oilfield has a bright application prospect.
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Evaluation Method of CO2 Sequestration and Enhanced Oil Recovery in an Oil Reservoir, as Applied to the Changqing Oilfields, China
Energy & Fuels, 2012Co-Authors: Xiaoliang Zhao, Xinwei LiaoAbstract:Injecting CO2 into oil reservoirs was proven to have a great CO2 sequestration capacity to reduce greenhouse gas emission and economic potentials via enhanced oil recovery (EOR). This paper proposes a CO2 sequestration estimation method based on the material balance method, which considered the CO2 displacement efficiency, CO2 sweep efficiency, CO2 dissolution, and some reservoir and fluid properties. The CO2 EOR estimation method is also proposed and refers to the traditional petroleum engineering method. In the evaluation method of CO2 sequestration and EOR potential, the sequestration coefficient and recovery factor are two important parameters. In this study, the Stream Tube simulation method is introduced to determine them. The evaluation method is applied to estimate the CO2 sequestration capacity and EOR potential in the Changqing oilfield of China. The Changqing oilfield province lies in the Ordos Basin of western China. Published data indicate that the Changqing oilfield includes about 22 oilfiel...
D D Yin - One of the best experts on this subject based on the ideXlab platform.
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evaluation of co2 enhanced oil recovery and sequestration potential in low permeability reservoirs yanchang oilfield china
Journal of The Energy Institute, 2014Co-Authors: Dongfeng Zhao, Xinwei Liao, D D YinAbstract:Abstract Sequestrating CO 2 in reservoirs can substantially enhance oil recovery and effectively reduce greenhouse gas emission. To evaluate the potential of CO 2 enhanced oil recovery (EOR) and sequestration for Yanchang Oilfield in China, a screening standard which was suitable for CO 2 -EOR and sequestration in Yanchang Oilfield was proposed based on its characteristics of strong heterogeneity, high water content and severe fluid channeling after water flooding. In addition, an efficient calculation method – Stream Tube simulation method was presented to figure out CO 2 sequestration coefficient and oil recovery factor. After screening and evaluating, it turned out that 148 out of 176 blocks in 22 oilfields were suitable for CO 2 -EOR and sequestration. CO 2 flooding after water flooding can produce 180.21 × 10 6 t more crude oil and sequestrate 223.38 × 10 6 t CO 2 . The average incremental oil recovery rate of miscible reservoirs was 12.49% and the average CO 2 sequestration coefficient was 0.27 t/t while the two values were 6.83% and 0.18 t/t for immiscible reservoirs. There are comparatively more reservoirs that are suitable for CO 2 -EOR and sequestration in Yanchang Oilfield than normal, which can obviously enhance oil recovery and means a great potential for CO 2 sequestration. CO 2 -EOR and sequestration in Yanchang Oilfield has a bright application prospect.