Experimental Investigation of Flow-Induced Vibration in Gas/Shear-Thinning Liquid Flows in Vertical Pipe

2020 ◽  
Author(s):  
Ruinan Lin ◽  
Ke Wang ◽  
Qing Li ◽  
Narakorn Srinil ◽  
Fangjun Shi
Keyword(s):  
Newtonian Fluid ◽  
Industrial Process ◽  
Flow Region ◽  
Shear Thinning ◽  
Maximum Energy ◽  
Internal Diameter ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Liquid Flows ◽  
Shear Thinning Fluid

Abstract The non-Newtonian shear-thinning fluid widely exists in the industrial process and the rheology exerts a significant influence on the flow pattern transition and flow-induced vibration (FIV). However, studies on the rheology effect of the liquid phase in the vertical upward two-phase flows are quite lacking due to the complexity of non-Newtonian fluid properties. In the present study, the vertical upward gas/shear-thinning liquid flows experiments are conducted on a rigid acrylic pipe with an internal diameter of 20 mm. Three different Carboxymethyl Cellulose (CMC) solutions are used as the non-Newtonian fluid, aimed at capturing a two-phase flow regime transition including the vertical slug, churn and annular flows. The results indicate that the maximum energy spectral densities of vibration occur at the slug-to-churn flow transition boundary at low liquid velocities and the annular flow region under high liquid velocities, respectively. The effects of the rheology of the shear-thinning fluid in terms of the flow patterns and FIV are also presented and discussed.

scholarly journals Liquid–Liquid Flows with Non-Newtonian Dispersed Phase in a T-Junction Microchannel

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 335
Author(s):  
Anna Yagodnitsyna ◽  
Alexander Kovalev ◽  
Artur Bilsky
Keyword(s):  
Flow Pattern ◽  
Dynamic Viscosity ◽  
Slug Flow ◽  
Shear Thinning ◽  
Continuous Phase ◽  
Immiscible Liquid ◽  
Dispersed Phase ◽  
Effective Dynamic ◽  
Liquid Flows ◽  
Shear Thinning Fluid

Immiscible liquid–liquid flows in microchannels are used extensively in various chemical and biological lab-on-a-chip systems when it is very important to predict the expected flow pattern for a variety of fluids and channel geometries. Commonly, biological and other complex liquids express non-Newtonian properties in a dispersed phase. Features and behavior of such systems are not clear to date. In this paper, immiscible liquid–liquid flow in a T-shaped microchannel was studied by means of high-speed visualization, with an aim to reveal the shear-thinning effect on the flow patterns and slug-flow features. Three shear-thinning and three Newtonian fluids were used as dispersed phases, while Newtonian castor oil was a continuous phase. For the first time, the influence of the non-Newtonian dispersed phase on the transition from segmented to continuous flow is shown and quantitatively described. Flow-pattern maps were constructed using nondimensional complex We0.4·Oh0.6 depicting similarity in the continuous-to-segmented flow transition line. Using available experimental data, the proposed nondimensional complex is shown to be effectively applied for flow-pattern map construction when the continuous phase exhibits non-Newtonian properties as well. The models to evaluate an effective dynamic viscosity of a shear-thinning fluid are discussed. The most appropriate model of average-shear-rate estimation based on bulk velocity was chosen and applied to evaluate an effective dynamic viscosity of a shear-thinning fluid. For a slug flow, it was found that in the case of shear-thinning dispersed phase at low flow rates of both phases, a jetting regime of slug formation was established, leading to a dramatic increase in slug length.

Study of Blood Flow in Micro-Channels Using Mixture Theory

2014 ◽  
Author(s):  
Wei-Tao Wu ◽  
Nadine Aubry ◽  
James F. Antaki ◽  
Mehrdad Massoudi
Keyword(s):  
Blood Flow ◽  
Newtonian Fluid ◽  
Mixture Theory ◽  
Shear Thinning ◽  
Characteristic Size ◽  
Navier Stokes ◽  
Two Phase ◽  
Plasma Skimming ◽  
Micro Channels ◽  
Complex Phenomena

It is known that in large vessels (whole) blood behaves as a Navier-Stokes (Newtonian) fluid; however, in a vessel whose characteristic dimension (e.g., a diameter in the range of 20 to 500 microns) is about the same size as the characteristic size of the blood cells, blood behaves as a non-Newtonian fluid, exhibiting complex phenomena, such as shear-thinning, stress relaxation, the Fahraeus effect, the plasma-skimming, etc.. Using the framework of mixture theory an Eulerian-Eulerian two phase model is applied to model blood flow, where the plasma is treated as Newtonian fluid and the RBCs are treated as shear thinning fluid.[5]

Studies on two-phase co-current air/non-Newtonian shear-thinning fluid flows in inclined smooth pipes

2007 ◽  
Vol 33 (9) ◽  
pp. 948-969 ◽  
Author(s):  
Jing-yu Xu ◽  
Ying-xiang Wu ◽  
Zai-hong Shi ◽  
Li-yun Lao ◽  
Dong-hui Li
Keyword(s):  
Fluid Flows ◽  
Shear Thinning ◽  
Two Phase ◽  
Shear Thinning Fluid

Propagation and Attenuation of Pressure Waves in Dispersed Two-Phase Flows

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Jaqueline Costa Martins ◽  
Paulo Seleghim
Keyword(s):  
Measurement Method ◽  
Indirect Measurement ◽  
Acoustic Energy ◽  
Internal Diameter ◽  
Pressure Waves ◽  
Two Phase ◽  
Oscillatory Solutions ◽  
Proposed Model ◽  
Dissipation Model ◽  
Liquid Flows

The propagation and attenuation of pressure waves in highly dispersed gas–liquid flows are investigated in this work, and an indirect measurement method is proposed to assess the attenuation coefficient in short pipelines. Additionally, a mechanistic acoustic energy dissipation model is derived from the oscillatory solutions of one-dimensional (1D) nondimensionalized mass and momentum equations to facilitate the interpretation of the results. Tests were performed on a 1500 m long, 50 mm internal diameter pipeline in which pressure disturbances were induced by suddenly opening leak valves. The results are consistent and in good agreement with the proposed attenuation model (±10% for 103 < Re < 104), therefore validating the proposed model and indirect measurement method.

scholarly journals An active particle in a complex fluid

2017 ◽  
Vol 823 ◽  
pp. 675-688 ◽  
Author(s):  
Charu Datt ◽  
Giovanniantonio Natale ◽  
Savvas G. Hatzikiriakos ◽  
Gwynn J. Elfring
Keyword(s):  
Newtonian Fluid ◽  
Slip Velocity ◽  
Shear Thinning ◽  
Reciprocal Theorem ◽  
Janus Particle ◽  
Active Particles ◽  
Complex Fluid ◽  
The Reciprocal Theorem ◽  
Fluid Rheology ◽  
Shear Thinning Fluid

In this work, we study active particles with prescribed surface velocities in non-Newtonian fluids. We employ the reciprocal theorem to obtain the velocity of an active spherical particle with an arbitrary axisymmetric slip velocity in an otherwise quiescent second-order fluid. We then determine how the motion of a diffusiophoretic Janus particle is affected by complex fluid rheology, namely viscoelasticity and shear-thinning viscosity, compared to a Newtonian fluid, assuming a fixed slip velocity. We find that a Janus particle may go faster or slower in a viscoelastic fluid, but is always slower in a shear-thinning fluid as compared to a Newtonian fluid.

Rheological studies of functional polyurethane composite

2017 ◽  
Vol 50 (3) ◽  
pp. 222-240
Author(s):  
Sayavur I Bakhtiyarov ◽  
Jimmie C Oxley ◽  
James L Smith ◽  
Philipp M Baldovi
Keyword(s):  
Newtonian Fluid ◽  
Power Law ◽  
Effective Viscosity ◽  
Aluminum Content ◽  
Fluid Model ◽  
Shear Thinning ◽  
Testing Time ◽  
Two Phase ◽  
Bingham Plastic ◽  
Polyurethane Composite

The rheological dynamic characteristics of the functional Polyurethane composite as well as its compounds ( triethanolamine (TEOA) and toluene-2,4-diisocyanate (TDI)) with and without solid additives (aluminum flakes) were experimentally measured using a computer-controlled mechanical spectrometer (rheometer) ARES-G2. Rheological studies showed that both components behave as viscous Newtonian fluids. TEOA exhibits a strong temperature-thickening behavior. TEOA with aluminum flake additives behaves as a viscous Newtonian fluid. The effective viscosity of the two-phase mixture increases with the concentration of the aluminum additive and decreases with the temperature rise. The rheometric tests showed that the effective viscosity of the TDI/Al mixture increases with the aluminum content. The mixture exhibits thermal-thickening and shear-thinning behaviors with the yield stress. The system can be described with the Bingham plastic model. It is determined that TEOA/TDI composite exhibits a strong time-thickening and shear-thinning behaviors. The rheological behavior of this composite can be described with the power-law generalized non-Newtonian fluid model. The effective viscosity of TEOA/TDI/Al composite increases with both the testing time (exponentially) and the aluminum content (polynomial) in the mixture. However, these shear-thinning composites obey the power-law generalized non-Newtonian fluid model, and their flow curves can be described by the logarithmic law.

scholarly journals Sedimentation of Two Side-by-Side Heavy Particles of Different Density in a Shear-Thinning Fluid with Viscoelastic Properties

2021 ◽  
Vol 11 (15) ◽  
pp. 7113
Author(s):  
Sensen Yang ◽  
Chengxu Tu ◽  
Minglu Dai ◽  
Xianfu Ge ◽  
Rongjun Xu ◽  
...  
Keyword(s):  
Newtonian Fluid ◽  
Viscoelastic Property ◽  
Particle Density ◽  
Petroleum Industry ◽  
Shear Thinning ◽  
Light Particle ◽  
Original Position ◽  
Particle Sedimentation ◽  
Settling Particle ◽  
Shear Thinning Fluid

Particle sedimentation has widely existed in nature and engineering fields, and most carrier fluids are non-Newtonian. Recently, the manipulation of a settling particle in liquid has been a topic of high interest to those involved in engineered processes such as composite materials, pharmaceutical manufacture, chemistry and the petroleum industry. Compared with Newtonian fluid, the viscosity of non-Newtonian fluid is closely related to the shear rate, leading to a single settling particle having different dynamic behaviors. In this article, the trajectories and velocities of two side-by-side particles of different densities (heavy and light) settling in a shear-thinning fluid with viscoelastic property were studied, as well as that for the corresponding single settling particle. Regardless of the difference in the particle density, the results show the two-way coupling interaction between the two side-by-side settling particles. As opposed to a single settling particle, the wake of the heavier particle can clearly attract or rebound the light particle due to the shear-thinning or viscoelastic property of the fluid. Regarding the trajectories of the light particle, three basic path types were found: (i) the light particle is first attracted and then repelled by the wake of the heavy one; (ii) the light particle approaches and then largely traces within the path of the heavy one in the limited field of view; (iii) the light particle is first slightly shifted away from its original position and then returns to this initial position. In addition to this, due to the existence of a corridor of reduced viscosity and negative wake generated by the viscoelastic property, the settling velocity of a light particle can exceed the terminal velocity of a single particle of the same density. On the other hand, the sedimentation of the light particle can induce the distinguishable transverse migration of the heavy one.

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