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Showing 1 to 16 of 16 for “"turbulent regime"”.
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Bubbling to turbulent regime transition in a 2D catalytic fluidized bed reactor
… m/s and 0.55 m/s. The onset velocity of the turbulent regime (uc) was determined as 0.4 m/s. The catalyst activity was optimized so that the effect of inter-phase mass transfer could be accentuated in the conversion reading. It was found that the general bubbling-turbulent model of Thompson …
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The Spatial Structure of Turbulent Rayleigh-Benard Convection
… present study are a manifestation, in the fully turbulent regime, of the cellular structures commonly observed at low Rayleigh numbers. The circulation cells are proposed as a physical description (not an explanation) of the phenomenon referred to in the literature as the wind of turbulence. They …
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Heat and Mass Transfer Performance and Flow Characteristics of an Offset -Strip Array at Reynolds Numbers Up to 100,000
… The PIV experiments reveal the flow to be in a turbulent, vortex shedding regime. The friction factor, Sherwood number, and Nusselt number are determined by experiment to be approximately twice that predicted using the best currently available correlations and models for offset-strip fin arrays. …
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Identification and Distribution Analysis of the Mid-phase in a Low-velocity Gas-solid Fluidized Bed
… directions in consideration of different flow regimes. The result shows that the turbulent regime contains a higher amount of mid-phase and the spatial mid-phase distributions within this regime present to be more heterogeneous. According to the analysis of the spatial distributions, the …
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Vortex-induced vibration of a linearly-sprung cylinder with nonlinear energy sinks
… for values of the Reynolds number in the laminar regime (20 ≤ Re ≤ 350) and well into the turbulent regime (Re ≈ 10,000), the addition of an NES to a linearly-sprung cylinder undergoing transverse VIV gives rise to a variety of physical phenomena not seen otherwise. We consider two NES …
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Effect of particle size on slugging fluidised beds
The work is concerned mainly with the slug flow regime in fluidised beds, where bubbles are of a size comparable to the column diameter. The fluidising fluid in all cases was air and the particles used were sand, quartz, ballotini and catalyst. The range of particle sizes was about 30 to 500 …
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Computations of Flow Structures and Heat Transfer in a Dimpled Channel at Low to Moderate Reynolds Number
… height) varies from Re = 25 in the laminar regime to Re = 2000 in the early turbulent regime. Fully developed flow and heat transfer conditions were assumed and a constant heat flux boundary condition was applied to the walls of the channel. In the laminar regime, the flow and heat transfer …
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Temporal and spatial growth of subharmonic disturbances in Falkner-Skan flows
The transition from laminar to turbulent flow in boundary-layers occurs in three stages: onset of two-dimensional TS waves, onset of three-dimensional secondary disturbances of fundamental or subharmonic type, and onset of the turbulent regime. In free flight conditions, subharmonic disturbances …
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Reduced-Order Models for the Prediction of Unsteady Heat Release in Acoustically Forced Combustion
… acoustically forced combustion in three disjoint regimes; highly turbulent, laminar, and the moderately turbulent flamelet regime. Particular emphasis is placed on simplification of the models to facilitate analytical solutions while still reflecting real phenomenology. Each derivation is treated …
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Turbulence models for the numerical prediction of transitional flows with RANSE
… turbulence models to predict the laminar-turbulent transitional flow in the boundary layer of streamlined bodies. Starting with a systematic study on a flat plate and arriving to transitional flow airfoils like the NACA 651-213 a=0.5. The RANSE solver is built on the libraries of …
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Experimental analysis of flow and turbulence characteristics in oscillatory boundary layers from LDV measurements
… Unlike steady boundary layer flows, the flow regime and bed roughness character of oscillatory flows change in time during the oscillation, a characteristic that introduces a high degree of complexity in the analysis. Experimental work in this topic started in the 1960s followed by numerical …
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Meshless Direct Numerical Simulation of Turbulent Incompressible Flows
… (DNS) and Large Eddy Simulations (LES) of turbulent incompressible flows in regular and irregular geometries. The proposed method is a combination of several efficient techniques found in different Computational Fluid Dynamic (CFD) procedures and it is a major improvement of the algorithm …
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Heat Transfer Augmentation Surfaces Using Modified Dimples/Protrusions
… ReH=200-15,000, covering the laminar to fully turbulent flow regimes and using two channel height geometries. While the smaller fin pitch channel has better performance in the low to medium Reynolds number range, both channel heights show similar trends in the fully turbulent regime. Moreover, …
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Direct numerical simulation of droplet-laden isotropic turbulence
… pathways for TKE exchange between the carrier turbulent flow and the flow inside the droplet. We also explain the role of the interfacial surface energy in the two-fluid TKE equation through work performed by surface tension. Furthermore, we derive the relationship between the power of surface …
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Transport of Heat and Momentum In Non-Equilibrium Wall-Bounded Flows
… the mean flow time scales are comparable to turbulent flow time scales, do not exhibit universal behaviors and cannot be characterized only in terms of local parameters. Pressure gradients, fast transients and complex geometries are among the sources that can perturb a flow from an …
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El drenaje subterráneo en el acuífero kárstico del cañón del río Lobos (Soria-Burgos)
… muy rápida y la presencia de un régimen turbulento en el entorno del Manantial de La Galiana. El Cañón fluviokárstico del río Lobos es el elemento geomorfológico externo más importante del sistema. Es un cañón excavado a lo largo de todo el Cuaternario. Los descensos del nivel de base del …