Effects of surface texturing in steady-state and transient flow conditions: Two-dimensional numerical simulation using a mass-conserving cavitation model

2014 ◽  
Vol 229 (4) ◽  
pp. 505-522 ◽  
Author(s):  
A Gherca ◽  
A Fatu ◽  
M Hajjam ◽  
P Maspeyrot
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Transient Flow ◽  
Surface Texturing ◽  
Two Dimensional ◽  
Flow Conditions ◽  
Cavitation Model

Studies on Two-Dimensional Contouring of High-Lift Turbine Airfoil Suction Surface as Separation-Control Device: Separation Suppression Under Steady-State Flow Conditions

2011 ◽  
Author(s):  
Ken-ichi Funazaki ◽  
Nozomi Tanaka ◽  
Takahiro Shiba ◽  
Haruyuki Tanimitsu ◽  
Masaaki Hamabe
Keyword(s):  
Steady State ◽  
Separation Bubble ◽  
Control Device ◽  
Surface Boundary ◽  
Two Dimensional ◽  
Flow Conditions ◽  
Steady State Flow ◽  
Suction Surface ◽  
Airfoil Surface ◽  
State Flow

The study the present authors have been working on is to develop a new method to increase aerodynamic loading of low-pressure turbine airfoils for modern aeroengines to a great extent, which is to achieve drastic reduction of their airfoil counts. For this purpose, this study proposes two-dimensional contouring of the airfoil suction surface as a device to suppress the separation bubble that causes large aerodynamic loss, especially at low Reynolds number condition. The main objective of this paper is to show how and to what extent the surface contouring without any other disturbances affects the suction surface boundary layer accompanying separation bubble. For comparison, rather conventional tripping wire technique is also employed as “local 2D surface contouring” to generate flow disturbances in order to suppress the separation bubble. All measurements are carried out under steady-state flow conditions with low freestream turbulence. It turns out from the detailed experiments and LES analysis that the newly proposed two-dimensional contouring of the airfoil surface can effectively suppress the separation bubble, resulting in significant improvement of cascade aerodynamic performance.

scholarly journals Comparison of CO2 Flow Behavior through Intact Siltstone Sample under Tri-Axial Steady-State and Transient Flow Conditions

2018 ◽  
Vol 8 (7) ◽  
pp. 1092 ◽  
Author(s):  
Chengpeng Zhang ◽  
Ranjith Pathegama Gamage ◽  
Mandadige Anne Perera
Keyword(s):  
Steady State ◽  
Transient Flow ◽  
Flow Behavior ◽  
Flow Conditions ◽  
Co2 Flow

Influences of Fluidic Interfaces on the Formation of Fine Scale Structure by Chaotic Mixing

1996 ◽  
Vol 118 (1) ◽  
pp. 40-47 ◽  
Author(s):  
D. F. Zhang ◽  
D. A. Zumbrunnen
Keyword(s):  
Transient Flow ◽  
Viscosity Ratio ◽  
Creeping Flow ◽  
Chaotic Mixing ◽  
Two Dimensional ◽  
Fine Scale ◽  
Flow Conditions ◽  
Computationally Efficient ◽  
Periodically Driven ◽  
Transient Flow Fields

A numerical model has been developed of two-dimensional chaotic mixing of immiscieble Newtonian fluids. A computationally efficient numerical methodology is employed which is well-suited to complex, evolving interfaces. Mixing was confined to a rectangular cavity with periodically driven upper and lower surfaces. Interfacial forces and the transient flow fields in each phase were considered to assess specifically the influences on interfacial morphology of interfacial tension and phase viscosity ratio under creeping flow conditions. Predicted morphologies are compared to those of solidified specimens synthesized by chaotic mixing in companion studies.

Critical Review of Stabilized Nanoparticle Transport in Porous Media

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Xiaoyan Meng ◽  
Daoyong Yang
Keyword(s):  
Porous Media ◽  
Steady State ◽  
Single Phase ◽  
Transient Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Flow Conditions ◽  
Nanoparticle Transport ◽  
Two Phase ◽  
Transport In Porous Media

Over the past few decades, due to the special features (i.e., easily produced, large-surface-area-to-volume ratio, and engineered particles with designed surface properties), nanoparticles have not only attracted great attentions from the oil and gas industry but also had various applications from drilling and completion, reservoir characterization, to enhanced oil recovery (EOR). As sensors or EOR agents, thus, fate and behavior of nanoparticles in porous media are essential and need to be investigated thoroughly. Nevertheless, most of the published review papers focus on particle transport in saturated porous media, and all of them are about steady-state flow conditions. So far, no attempts have been extended to systematically review current knowledge about nanoparticle transport in porous media with single-phase and two-phase flow systems under both steady-state and unsteady-state conditions. Accordingly, this review will discuss nanoparticle transport phenomena in porous media with its focus on the filtration mechanisms, the underlying interaction forces, and factors dominating nanoparticle transport behavior in porous media. Finally, mathematical models used to describe nanoparticle transport in porous media for both single-phase flow and two-phase flow under steady-state and transient flow conditions will be summarized, respectively.

Compaction of Anisotropic Granular Materials: Symmetry Effects

2006 ◽  
Vol 518 ◽  
pp. 355-360
Author(s):  
Lj. Budinski-Petković ◽  
M. Petković ◽  
Z.M. Jakšić ◽  
S.B. Vrhovac
Keyword(s):  
Numerical Simulation ◽  
Monte Carlo ◽  
Steady State ◽  
Granular Materials ◽  
Power Law ◽  
Symmetry Axis ◽  
Random Sequential Adsorption ◽  
Two Dimensional ◽  
Sequential Adsorption ◽  
First Time

We perform numerical simulation of a lattice model for the compaction of a granular material based on the idea of reversible random sequential adsorption. Reversible random sequential adsorption of objects of various shapes on a two−dimensional triangular lattice is studied numerically by means of Monte Carlo simulations. The growth of the coverage ρ(t) above the jamming limit to its steady−state value ρ∞ is described by a pattern ρ (t) = ρ∞ − ρEβ[−(t/τ)β], where Eβ denotes the Mittag−Leffler function of order β ∈ (0, 1). For the first time, the parameter τ is found to decay with the desorption probability P− according to a power law τ = A P− −γ. Exponent γ is the same for all shapes, γ = 1.29 ± 0.01, but parameter A depends only on the order of symmetry axis of the shape. Finally, we present the possible relevance of the model to the compaction of granular objects of various shapes.

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