scholarly journals Theoretical Analysis of Fractional Viscoelastic Flow in Circular Pipes: Parametric Study

2020 ◽  
Vol 10 (24) ◽  
pp. 9080
Author(s):  
Dmitry Gritsenko ◽  
Roberto Paoli
Keyword(s):  
Fluid Dynamics ◽  
Pipe Flow ◽  
Mutual Influence ◽  
Viscoelastic Flow ◽  
Elastic Parameters ◽  
Time Dynamics ◽  
Circular Pipes ◽  
Classical Models ◽  
Fractional Orders ◽  
Limiting Value

Pipe flow is one of the most commonly used models to describe fluid dynamics. The concept of fractional derivative has been recently found very useful and much more accurate in predicting dynamics of viscoelastic fluids compared with classic models. In this paper, we capitalize on our previous study and consider space-time dynamics of flow velocity and stress for fractional Maxwell, Zener, and Burgers models. We demonstrate that the behavior of these quantities becomes much more complex (compared to integer-order classical models) when adjusting fractional order and elastic parameters. We investigate mutual influence of fractional orders and consider their limiting value combinations. Finally, we show that the models developed can be reduced to classical ones when appropriate fractional orders are set.

scholarly journals Theoretical Analysis of Fractional Viscoelastic Flow in Circular Pipes: General Solutions

2020 ◽  
Vol 10 (24) ◽  
pp. 9093
Author(s):  
Dmitry Gritsenko ◽  
Roberto Paoli
Keyword(s):  
Fractional Calculus ◽  
Biomedical Applications ◽  
Viscoelastic Flow ◽  
Shear Stresses ◽  
Viscoelastic Flows ◽  
Extensive Literature ◽  
Circular Pipes ◽  
Different Types ◽  
Pipe Radius ◽  
Fractional Orders

Fractional calculus is a relatively old yet emerging field of mathematics with the widest range of engineering and biomedical applications. Despite being an incredibly powerful tool, it, however, requires promotion in the engineering community. Rheology is undoubtedly one of the fields where fractional calculus has become an integral part of cutting-edge research. There exists extensive literature on the theoretical, experimental, and numerical treatment of various fractional viscoelastic flows in constraint geometries. However, the general theoretical approach that unites several most commonly used models is missing. Here we present exact analytical solutions for fractional viscoelastic flow in a circular pipe. We find velocity profiles and shear stresses for fractional Maxwell, Kelvin–Voigt, Zener, Poynting–Thomson, and Burgers models. The dynamics of these quantities are studied with respect to normalized pipe radius, fractional orders, and elastic moduli ratio. Three different types of behavior are identified: monotonic increase, resonant, and aperiodic oscillations. The models developed are applicable in the widest material range and allow for the alteration of the balance between viscous and elastic properties of the materials.

Fluid dynamics of the resonance tube

1970 ◽  
Vol 43 (2) ◽  
pp. 369-384 ◽  
Author(s):  
E. Brocher ◽  
C. Maresca ◽  
M.-H. Bournay
Keyword(s):  
Fluid Dynamics ◽  
Kinetic Energy ◽  
Sound Speed ◽  
Pressure Fluctuations ◽  
Oscillation Amplitude ◽  
Cylindrical Body ◽  
Expansion Phase ◽  
Resonance Tube ◽  
Limiting Value ◽  
Good Agreement

Using a simplified wave-diagram and the gas-speed/sound-speed diagram, it is shown how the oscillations start and grow within a resonance tube. It is found that the oscillation amplitude tends to a limiting value which is obtained when the jet is fully swallowed by the tube during the phase of compression of the cycle. Experiments are carried out for jet Mach numbers from 0·1 up to 2. To achieve an adequate evacuation of the tube in the expansion phase, a thin cylindrical body must be used, which is laid along the axis of the jet to produce a wake and a correlative local deficiency of the kinetic energy of the jet. Measured amplitudes of pressure fluctuations are in good agreement with theoretical values.

1218 Experimental Study of the Flow in Helical Circular Pipes(Torsion Effect on the Turbulence of Pipe Flow)

2011 ◽  
Vol 2011.49 (0) ◽  
pp. 387-388
Author(s):  
Kenichi WADA ◽  
Yasutaka HAYAMIZU ◽  
Shinichiro YANASE ◽  
Susumu GOTO ◽  
Kyoji YAMAMOTO
Keyword(s):  
Experimental Study ◽  
Pipe Flow ◽  
Circular Pipes ◽  
Torsion Effect

On Deriving High Pressure Empirical Multiphase Forcing Functions From CFD Analysis

2019 ◽  
Author(s):  
Olivier Macchion ◽  
Stefan Belfroid ◽  
Leszek Stachyra ◽  
Atle Jensen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Pressure ◽  
Pipe Flow ◽  
Experimental Results ◽  
Internal Diameter ◽  
Cfd Analysis ◽  
Empirical Correlations ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Cfd

Abstract Computational Fluid Dynamics (CFD) simulations are used to predict the flow-induced forcing in high-pressure multiphase pipe flow. Furthermore, empirical correlations from the literature is compared and validated against computational and experimental results. Based on the CFD results and in conjunction with the reference 6” (internal diameter (ID)) data, new scaling rules are proposed.

scholarly journals Volume ignition via time-like detonation in pellet fusion

2015 ◽  
Vol 33 (2) ◽  
pp. 279-282 ◽  
Author(s):  
L.P. Csernai ◽  
D.D. Strottman
Keyword(s):  
Fluid Dynamics ◽  
Pulse Heating ◽  
Relativistic Fluid Dynamics ◽  
Time Dynamics ◽  
Relativistic Fluid ◽  
Surrounding Space ◽  
Short Time ◽  
Heating Up ◽  
Volume Ignition ◽  
Supercritical Temperature

AbstractRelativistic fluid dynamics and the theory of relativistic detonation fronts are used to estimate the space–time dynamics of the burning of the Deuterium–Tritium fuel in laser-driven pellet fusion experiments. The initial “High foot” heating of the fuel makes the compressed target transparent to radiation, and then a rapid ignition pulse can penetrate and heat up the whole target to supercritical temperatures in a short time, so that most of the interior of the target ignites almost simultaneously and instabilities will have no time to develop. In these relativistic, radiation-dominated processes both the interior, time-like burning front, and the surrounding space-like part of the front will be stable against Rayleigh–Taylor instabilities. To achieve this rapid, volume ignition the pulse heating up the target to supercritical temperature should provide the required energy in less than 10 ps.

scholarly journals Internal Fluid Flow: The Fluid Dynamics of Flow on Pipes and Ducts and Fundamentals of Pipe Flow

1982 ◽  
Vol 104 (1) ◽  
pp. 129-129 ◽  
Author(s):  
A. J. Ward-Smith ◽  
Robert P. Benedict ◽  
Warren M. Hagist
Keyword(s):  
Fluid Dynamics ◽  
Fluid Flow ◽  
Pipe Flow ◽  
Internal Fluid ◽  
Internal Fluid Flow

Flow Analysis in Pipe of a Manifold Block

2012 ◽  
Vol 6 (4) ◽  
pp. 494-501 ◽  
Author(s):  
Osamu Abe ◽  
◽  
Tetsuhiro Tsukiji ◽  
Takeshi Hara ◽  
Kazutoshi Yasunaga ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pipe Flow ◽  
Hydraulic System ◽  
Flow Analysis ◽  
Cfd Analysis ◽  
Hydraulic Systems ◽  
Pressure Drops ◽  
Computational Fluid Dynamics Cfd ◽  
Pipeline Design

Manifold blocks are recently used to connect hydraulic components in hydraulic system, which has flow channel inside. They are useful for reducing the size and weight of hydraulic systems. This paper deals with solid manifold block and laminated manifold block. They are different from machining. We investigate pressure drops of their pipe flow with Computational Fluid Dynamics (CFD) and compare those of two types. And then, we conduct experiment, measuring pressure and visualization, to validate the results of CFD analysis. By using these results, we are intended to obtain guidelines for pipeline design in laminated manifold block.

scholarly journals Modelling Considerations in the Simulation of Hydrogen Dispersion within Tunnel Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Idris Ismail ◽  
Hisayoshi Tsukikawa ◽  
Hiroshi Kanayama
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Hydrogen Gas ◽  
Convection Flow ◽  
Target Model ◽  
Computational Fluid Dynamics Cfd ◽  
Air Speed ◽  
Free Open Source ◽  
Limiting Value

The flow of leaked hydrogen gas in tunnel structures is simulated through a free, open source computational fluid dynamics (CFD) code for incompressible thermal convection flow. A one-fifth scale experimental model of a real tunnel is the target model to be simulated. To achieve this, studies on the effects of different boundary conditions, in particular, the wind speed, are carried out on smaller tunnel structures with the same hydrogen inlet boundary conditions. The results suggest a threshold/limiting value of air speed through tunnel. The target model computed with the most suitable boundary conditions shows some agreement with the experimental ones. A method to compute the buoyancy factor used in the code is also presented.

Computational Fluid Dynamics Computations Using a Preconditioned Krylov Solver on Graphical Processing Units

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Amit Amritkar ◽  
Danesh Tafti
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pipe Flow ◽  
Turbulent Channel Flow ◽  
General Purpose ◽  
Processing Unit ◽  
Double Precision ◽  
Single Precision ◽  
Central Processing ◽  
Graphical Processing

Graphical processing unit (GPU) computation in recent years has seen extensive growth due to advancement in both hardware and software stack. This has led to increase in the use of GPUs as accelerators across a broad spectrum of applications. This work deals with the use of general purpose GPUs for performing computational fluid dynamics (CFD) computations. The paper discusses strategies and findings on porting a large multifunctional CFD code to the GPU architecture. Within this framework, the most compute intensive segment of the software, the BiCGStab linear solver using additive Schwarz block preconditioners with point Jacobi iterative smoothing is optimized for the GPU platform using various techniques in CUDA Fortran. Representative turbulent channel and pipe flow are investigated for validation and benchmarking purposes. Both single and double precision calculations are highlighted. For a modest single block grid of 64 × 64 × 64, the turbulent channel flow computations showed a speedup of about eightfold in double precision and more than 13-fold for single precision on the NVIDIA Tesla GPU over a serial run on an Intel central processing unit (CPU). For the pipe flow consisting of 1.78 × 106 grid cells distributed over 36 mesh blocks, the gains were more modest at 4.5 and 6.5 for double and single precision, respectively.

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