scholarly journals Fissure Grouting Mechanism Accounting for the Time-Dependent Viscosity of Silica Sol

ACS Omega ◽  
2021 ◽  
Author(s):  
Weijie Zhang ◽  
Fei Yang ◽  
Chenghao Han ◽  
Qian Ren ◽  
Ziyu Peng ◽  
...  
Keyword(s):  
Silica Sol ◽  
Time Dependent ◽  
Dependent Viscosity

scholarly journals Influence of Microcapsule Size and Shell Polarity on the Time-Dependent Viscosity of Geopolymer Paste

2018 ◽  
Vol 57 (29) ◽  
pp. 9457-9464 ◽  
Author(s):  
Vinh Duy Cao ◽  
Shima Pilehvar ◽  
Carlos Salas-Bringas ◽  
Anna M. Szczotok ◽  
Nu Bich Duyen Do ◽  
...  
Keyword(s):  
Time Dependent ◽  
Dependent Viscosity ◽  
Geopolymer Paste

scholarly journals Transient Analysis of Grout Penetration With Time-Dependent Viscosity Inside 3D Fractured Rock Mass by Unified Pipe-Network Method

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1122 ◽  
Author(s):  
Zizheng Sun ◽  
Xiao Yan ◽  
Rentai Liu ◽  
Zhenhao Xu ◽  
Shucai Li ◽  
...  
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
High Efficiency ◽  
Fractured Rock ◽  
Time Dependent ◽  
Pipe Network ◽  
Fractured Rock Mass ◽  
Network Method ◽  
The Stability ◽  
Dependent Viscosity

Grouting is widely used for mitigating the seepage of underground water and enhancing the stability of fractured rock mass. After injection, the viscosity of the grout gradually increases until solidification. Conventional multifield analysis models ignoring such effects greatly overestimate the penetration region of the grout and the stability of the grouted rock structures. Based on the 3D unified pipe-network method (UPM), we propose a novel numerical model considering the time-dependent viscosity of the grout, therein being a quasi-implicit approach of high efficiency. The proposed model is verified by comparing with analytical results and a time-wise method. Several large-scale 3D examples of fractured rock mass are considered in the numerical studies, demonstrating the effectiveness and robustness of the proposed method. The influence of the time-dependent viscosity, fracture properties, and grouting operation methods are discussed for the grout penetration process.

Numerical simulation of physiologically relevant pulsatile flow of blood with shear-rate-dependent viscosity in a stenosed blood vessel

2018 ◽  
Vol 11 (06) ◽  
pp. 1850082
Author(s):  
Subrata Mukhopadhyay ◽  
Mani Shankar Mandal ◽  
Swati Mukhopadhyay
Keyword(s):  
Numerical Simulation ◽  
Blood Flow ◽  
Blood Vessel ◽  
Pulsatile Flow ◽  
Time Dependent ◽  
Governing Equations ◽  
Rate Dependent ◽  
Realistic Situation ◽  
Newtonian Case ◽  
Dependent Viscosity

Pulsatile flow of blood in a blood vessel having time-dependent shape (diameter) is investigated numerically in order to understand some important physiological phenomena in arteries. A smooth axi-symmetric cosine shaped constriction is considered. To mimic the realistic situation as far as possible, viscosity of blood is taken to be non-uniform, a shear-thinning viscosity model is considered and a physiologically relevant pulsatile flow is introduced. Taking advantage of axi-symmetry in the proposed problem, the stream function–vorticity formulation is used to solve the governing equations for blood flow. Effect of different parameters associated with the problem on the flow pattern has been investigated and disparities from the Newtonian case are discussed in detail.

Crustal viscosity and its control on volcanic ground deformation patterns

2020 ◽  
Author(s):  
Matthew Head ◽  
James Hickey ◽  
Jo Gottsmann ◽  
Nico Fournier
Keyword(s):  
Volume Change ◽  
Ground Deformation ◽  
Geothermal Gradient ◽  
Time Dependent ◽  
Temperature Dependent Viscosity ◽  
Volcanic System ◽  
Change Models ◽  
Dependent Viscosity ◽  
Deformation Patterns ◽  
Underlying Processes

<p>Episodes of ground deformation, relating to the unrest of a volcanic system, are often readily identifiable within geodetic timeseries (e.g. GPS, InSAR). However, the underlying processes facilitating this deformation are more enigmatic. By modelling the observed deformation signals, the ultimate aim is to infer characteristics of the deforming reservoir; namely the size and time-dependent evolution of the system and, potentially, the fluxes of magma involved. These parameters can be estimated using simple elastic models, but the presence of shallow or long-lived magmatic systems can significantly perturb the local geothermal gradient and invalidate the elastic approximation. Inelastic rheological effects are increasingly utilised to account for these elevated thermal regimes, where a component of viscous (time-dependent) behaviour is expected to characterise the observed deformation field.</p><p>Here, our investigations are concentrated on Taupō volcano, New Zealand, the site of several catastrophic caldera-forming eruptions. We use 3D thermomechanical models of the Lake Taupō region, featuring thermal constraints and heterogeneous crustal properties, to compare the commonly-used Maxwell and Standard Linear Solid (SLS) viscoelastic configurations under contrasting deformation mechanisms; a pressure condition (stress-based) and a volume-change (strain-based). By referring to models allocated a single viscosity value, we investigate the influence of a temperature-dependent viscosity distribution on the predicted spatiotemporal deformation patterns. Comparisons of the overpressure models highlights the influence of the crustal viscosity structure on deformation timescales, by enabling the SLS rheology to account for both abrupt and long-term deformation signals. For the Maxwell rheology, we show that the viscosity distribution results in unexpected deformation patterns, both spatially and temporally, and so query the suitability of this rheology in other model setups. Further to this, the deformation patterns in volume-change models are governed by the resulting stress response, and the effect of the viscosity structure on its propagation. Ultimately, we demonstrate that variations in crustal viscosity greatly influence spatiotemporal deformation patterns, more so than heterogeneous mechanical parameters alone, and consequently have a large impact on the inferences of the underlying processes and their time-dependent evolution. The inclusion of a crustal viscosity structure is therefore an important consideration when modelling volcanic deformation signals.</p>

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