Analysis of temperature-sensitive hydrogel microvalves in a T-junction flow sorter using full scale fluid–structure interaction

2020 ◽  
Vol 31 (11) ◽  
pp. 1371-1382
Author(s):  
Elham Khanjani ◽  
Arash Kargar-Estahbanaty ◽  
Ali Taheri ◽  
Mostafa Baghani

Hydrogels have attracted attention in microfluidic applications as sensors and actuators due to their ability to undergo huge volume changes when subjected to environmental stimuli. In this study, a T-junction flow sorter is numerically investigated. Each of the branches involves one hydrogel microvalve with reverse sensitivity to temperature changes. The valve’s functionality is studied with and without considering fluid–structure interaction for various inlet pressures. The results of fluid–structure interaction and non-fluid–structure interaction solutions, such as fluid flow rate and valves close temperature, are presented and compared. In order to reduce hydrogel’s response time, the solution is employed for multiple valves patterns. It can be concluded that the hydrogel deformation due to the fluid pressure has a significant effect on the valves’ operational parameters which cannot be ignored in design and analysis.

2018 ◽  
Vol 29 (20) ◽  
pp. 3960-3971 ◽  
Author(s):  
H Mazaheri ◽  
AH Namdar ◽  
A Amiri

Smart hydrogels are soft materials which can be applied in sensors and actuators especially in microfluidics in which the fluid–structure interaction is important. In this work, first, the behavior of a one-way hydrogel micro-valve is investigated by considering the fluid–structure interaction effect for a specified geometry of the micro-valve. Second, both the fluid–structure interaction and non-fluid–structure interaction simulations are conducted to study the fluid flow effect on the operational parameters of the micro-valve. The obtained results show that the fluid–structure interaction effects are important and have a considerable influence on the micro-valve parameters especially on its closing temperature. Thereafter, a precise study on the micro-valve is executed by considering the micro-valve operational parameters such as inlet pressure, head size, crosslinking density, and breaking pressure at different temperatures. The results show the importance of considering the fluid–structure interaction effect in the design of these devices.


2019 ◽  
Vol 11 (3) ◽  
pp. 168781401982858
Author(s):  
Liaojun Zhang ◽  
Shuo Wang ◽  
Guojiang Yin ◽  
Chaonian Guan

Current studies on the operation of the axial pump mainly focus on hydraulic performances, while the coupled interaction between the fluid and structure attracts little attention. This study aims to provide numerical investigation into the vibration features in a vertical axial pump based on two-way iterative fluid–structure interaction method. Three-dimensional coupling model was established with high-quality structured grids of ADINA software. Turbulent flow features were studied under design condition, using shear–stress transport k-ω turbulence model and sliding mesh approach. Typical measure points along and perpendicular to flow direction in fluid domain were selected to analyze pressure pulsation features of the impeller and fixed guide vane. By contrast, vibration features of equivalent stress in corresponding structural positions were investigated and compared based on fluid–structure interaction method. In order to explore fluid–structure interaction vibration mechanism, distribution of main frequencies and amplitudes of the measure points was presented based on the Fast Fourier Transformation method. The results reveal the time and frequency law of fluid pressure pulsation and structural vibration at the same position in the vertical axial pump while additionally provide important theoretical guidance for optimization design and safe operation of the vertical axial pump.


2010 ◽  
Vol 455 ◽  
pp. 146-150
Author(s):  
Fang Cao ◽  
Yong Wang ◽  
Y.T. An

According to the real structure and work condition of a large-scale gas control valve used in recycling generating electricity project, a sequential fluid-structure interaction system model of control valve is set up, the coupling of fluid and valve plug is studied. The complicated fluid pressure, stress and deformation of balanced valve plug and stem at different control valve openings are investigated. The root cause of plug vibration by fluid is revealed. The natural frequency and modes of vibration are obtained, which could verify whether the design overcomes resonance. All of these are in favor of realizing design optimization in fluid-structure interaction and are of great practical significance for advancing study on large-scale control valves.


Author(s):  
Esfandyar Kouhi ◽  
Yos Morsi

In this paper the fluid structure interaction in stentless aortic heart valve during acceleration phase was performed successfully using the commercial ANSYS/CFX package. The aim is to provide unidirectional coupling FSI analysis of physiological blood flow within an anatomically corrected numerical model of stentless aortic valve. Pulsatile, Newtonian, and turbulent blood flow rheology at aortic level was applied to fluid domain. The proposed structural prosthesis had a novel multi thickness leaflet design decreased from aortic root down to free age surface. An appropriate interpolation scheme used to import the fluid pressure on the structure at their interface. The prosthesis deformations over the acceleration time showed bending dominant characteristic at early stages of the cardiac cycle. More stretching and flattening observed in the rest of the times steps. The multi axial Von Mises stress data analysis was validated with experimental data which confirmed the initial design of the prosthesis.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Ricardo Faria ◽  
Sérgio Oliveira ◽  
Ana L. Silvestre

We consider a dam-water system modeled as a fluid-structure interaction, specifically, a coupled hyperbolic second-order problem, formulated in terms of the displacement of the structure and the fluid pressure. Firstly, we investigate the well posedness of the corresponding variational formulation using Galerkin approximations, energy estimates, and mollification. Then, we apply the finite element method along with the state-space representation of the discrete problem in order to perform a 3D numerical simulation of Cabril arch dam (Zêzere river, Portugal). The numerical model is validated by comparison with available experimental data from a monitoring vibration system installed in Cabril dam.


1987 ◽  
Vol 109 (2) ◽  
pp. 244-248 ◽  
Author(s):  
I.-W. Yu

The subspace iteration method, commonly used for solving symmetric eigenvalue problems in structural dynamics, can be extended to solve nonsymmetric fluid-structure interaction problems in terms of fluid pressure and structural displacement. The two cornerstones for such extension are a nonsymmetric equation solver for the inverse iteration and a nonsymmetric eigen-procedure for subspace eigen-solution. The implementation of a nonsymmetric equation solver can easily be obtained by modifying the existing symmetric procedure; however, the nonsymmetric eigen-solver requires a new procedure such as the real form of the LZ-algorithm. With these extensions the subspace iteration method can solve large fluid-structure interaction problems by extracting a group of eigenpairs at a time. The method can generally be applied to compressible and incompressible fluid-structure interaction problems.


2014 ◽  
Vol 513-517 ◽  
pp. 4298-4301
Author(s):  
Xiu Quan Lu ◽  
Wei Cai ◽  
Wen Xing Ma ◽  
Yue Shi Wu ◽  
Wen Xu

In the design and manufacturing process of the hydrodynamic coupling, the fluid pressure on the impeller is difficult to calculate when analyzing the strength of the impeller. We can use the one-way fluid-structure interaction analysis. When interpolate the pressure on the flow field and structural coordinate values, choosing reasonable interpolation method can reduce the amount of computation, improve accuracy, simplify product design and manufacturing process. This article is based on one-way fluid-structure interaction analysis. We compare the four interpolation method in MATLAB, conclude that the spline interpolation is better than others. It is the most suitable for practical applications, which can simplify the design of the manufacturing process of the hydrodynamic coupling.


Author(s):  
Jeremiah N. Mpagazehe ◽  
C. Fred Higgs

In many tribological applications, such as journal bearings and gears, a fluid film is used to accommodate velocity between moving surfaces. To model the behavior of this film and to predict its ability to carry load, the Reynolds equation is predominantly employed. As computational processing power continues to increase, computational fluid dynamics (CFD) is increasingly being employed to predict the fluid behavior in lubrication environments. Using CFD is advantageous in that it can provide a more general approximation to the Navier-Stokes equations than the Reynolds equation. Moreover, using CFD allows for the simulation of multiphase flows as could occur during bearing contamination and bearing exit conditions. Because the bearing surfaces move relative to each other as they obtain equilibrium with the fluid pressure, there is a need to incorporate the moving boundary into the CFD calculation, which is a non-trivial task. In this work, a fluid-structure interaction (FSI) technique is explored as an approach to model the dynamic coupling between the moving bearing surfaces and the lubricant. The benefits of using an FSI approach are discussed and the results of its implementation in a lubricated sliding contact model are presented.


2018 ◽  
Vol 15 (06) ◽  
pp. 1850045
Author(s):  
C. Le-Quoc ◽  
Linh A. Le ◽  
V. Ho-Huu ◽  
P. D. Huynh ◽  
T. Nguyen-Thoi

Proper generalized decomposition (PGD), a method looking for solutions in separated forms, was proposed recently for solving highly multidimensional problems. In the PGD, the unknown fields are constructed using separated representations, so that the computational complexity scales linearly with the dimension of the model space instead of exponential scaling as in standard grid-based methods. The PGD was proven to be effective, reliable and robust for some simple benchmark fluid–structure interaction (FSI) problems. However, it is very hard or even impossible for the PGD to find the solution of problems having complex boundary shapes (i.e., problems of fluid flow with arbitrary complex geometry obstacles). The paper hence further extends the PGD to solve FSI problems with arbitrary boundaries by combining the PGD with the immersed boundary method (IBM) to give a so-called immersed boundary proper generalized decomposition (IB-PGD). In the IB-PGD, a forcing term constructed by the IBM is introduced to Navier–Stokes equations to handle the influence of the boundaries and the fluid flow. The IB-PGD is then applied to solve Poisson’s equation to find the fluid pressure distribution for each time step. The numerical results for three problems are presented and compared to those of previous publications to illustrate the robustness and effectiveness of the IB-PGD in solving complex FSI problems.


2019 ◽  
Vol 13 (1) ◽  
pp. 289-300 ◽  
Author(s):  
Bui Pham Duc Tuong ◽  
Phan Duc Huynh ◽  
Tan-Trung Bui ◽  
Vasilis Sarhosis

Aims: The paper analyzes the effectiveness of tuned liquid damper in controlling the vibration of high rise building. The new contribution is considering the fluid-structure interaction of a water tank as a Tuned Liquid Dampers (TLD). Background: Currently, buildings are being built higher and higher, which requires TLDs to be larger as well. Therefore, the fluid pressure acting on the tank wall is more significant. In previous studies of liquid sloshing in TLDs, researchers simply ignored the effect of liquid pressure acting on the tank walls by making the assumption that the tanks are rigid. Currently, the failure of a tank because of FSI occurs regularly, so this phenomenon cannot be ignored when designing the tanks in general and TLDs in particular. Objective: To investigate the thickness of the tank wall affect to the TLD mechanism. Method: Numerical method was used for this research. Results: A TLD could be easy to design; however one could not bypass the fluid-structure interaction by assuming the tank wall is rigid. Conclusion: This kind of damper is very good to mitigate the dynamic response of structrure.


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