During conventional oil and gas well drilling, weight on bit (WOB) and torque are measured and controlled at the wellhead. However, due to significant transmission lag in thousands of meters long wells, accurate contr...
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During conventional oil and gas well drilling, weight on bit (WOB) and torque are measured and controlled at the wellhead. However, due to significant transmission lag in thousands of meters long wells, accurate control is unattainable resulting in extremely low drilling efficiency. A novel approach utilizing a coiled tubing drilling (CTD) robot for real-time control of bottom hole WOB and indirect torque regulation via WOB manipulation is proposed. To achieve automatic control, it is imperative to conduct a thorough study of the CTD robot's dynamic characteristics. Through the study, the fluid-structure interaction model of axial torsional dynamics was established for the first time. The factors, including BHA, screw performance, bit performance, rate of penetration (ROP) equation, torque equation, rheological characteristics of drilling fluid and other relevant aspects were comprehensively considered. The effects of drilling fluid displacement (DFD) and WOB fluctuations on the torsional vibration characteristics of the CTD robot system were analyzed. It was found that DFD fluctuation frequency are the main controlling factors affecting the axial torsional dynamic characteristics. By keeping the fluctuation frequency of DFD much higher than 19 Hz, the amplitude and instability of bit vibration can be effectively suppress. This research is beneficial for controlling WOB with CTD robot and suppressing the vibration of the drill bit.
Airborne wind energy (AWE) is an emerging technology for the conversion of wind energy into electricity. There are many types of AWE systems, and one of them flies crosswind patterns with a tethered aircraft connected...
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Airborne wind energy (AWE) is an emerging technology for the conversion of wind energy into electricity. There are many types of AWE systems, and one of them flies crosswind patterns with a tethered aircraft connected to a generator. The objective is to gain a proper understanding of the unsteady interaction of air and this flexible and dynamic system during operation, which is key to developing viable, large AWE systems. In this work, the effect of wing deformation on an AWE system performing a crosswind flight maneuver was assessed using high-fidelity time-varying fluid-structure interaction simulations. This was performed using a partitioned and explicit approach. A computational structural mechanics (CSM) model of the wing structure was coupled with a computational fluid dynamics (CFD) model of the wing aerodynamics. The Chimera/overset technique combined with an arbitrary Lagrangian-Eulerian (ALE) formulation for mesh deformation has been proven to be a robust approach to simulating the motion and deformation of an airborne wind energy system in CFD simulations. The main finding is that wing deformation in crosswind flights increases the symmetry of the spanwise loading. This property could be used in future designs to increase the efficiency of airborne wind energy systems.
An efficient and new methodology to deal with fluidstructureinteraction at high Reynolds number flows is presented in this article. It relies on the coupling of the lattice Boltzmann method and the immersed boundary...
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An efficient and new methodology to deal with fluidstructureinteraction at high Reynolds number flows is presented in this article. It relies on the coupling of the lattice Boltzmann method and the immersed boundary method with a second order predictor corrector model for the structure. The effect of the lagrangian weight of the immersed boundary method is also analyzed in the context of fluidstructureinteraction. Both curved and moving boundaries are considered, and several methods to calculate the lagrangian weight are compared on relevant test-cases: the laminar flow around a cylinder at Reynolds number Re = 100, the Poiseuille flow in a 2D channel and a 3D fluid-structure interaction test case: a deformable flapping flag immersed in a laminar flow. A convergence study in space and time is performed and the three following parameters are investigated: the number of lagrangian markers along the boundary, the value of the lagrangian weight and the shape of the discrete delta function used in the immersed boundary. Finally, the novelty of the paper is two-fold: a new expression of the lagrangian weight which is found to reduce the error by 20% in the case of fluid-structure interaction, and the coupling of a turbulence model with a second order predictor corrector model for improved stability and accuracy. This numerical methodology is found here to be accurate for challenging cases with high added mass effect and high Reynolds number flows.& COPY;2023 Elsevier Inc. All rights reserved.
This study presents a numerical investigation of a 2D flexible flat plate dynamics, immersed in a fluid flow with a Reynolds number, based on its chord, of 2000. The plate is animated by a forced sinusoidal pitching m...
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This study presents a numerical investigation of a 2D flexible flat plate dynamics, immersed in a fluid flow with a Reynolds number, based on its chord, of 2000. The plate is animated by a forced sinusoidal pitching movement, whose amplitude is 10 circle from its leading edge. Various materials are considered for the structure, from rigid materials to more flexible ones. The fluid-structure interaction (FSI) effects are taken into account using a partitioned implicit coupling scheme. The Arbitrary Lagrangian-Eulerian (ALE) formulation of the Navier-Stokes equations is applied and the anisotropic diffusion equation is solved to determine the displacements of the fluid domain mesh. The numerical results are validated with experimental ones. A good agreement with the experimental results is obtained. Afterwards, it is shown that under the considered dynamics of the plate, the flexibility of the structure tends to increase the lift and the drag but decrease the thrust. In addition, this produces an acceleration of the fluid flow in the wake of the plate.
Thoracic endovascular aortic repair (TEVAR) has developed to be the most effective treatment for aortic diseases. This study aims to evaluate the biomechanical implications of the implanted endograft after TEVAR. We p...
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Thoracic endovascular aortic repair (TEVAR) has developed to be the most effective treatment for aortic diseases. This study aims to evaluate the biomechanical implications of the implanted endograft after TEVAR. We present a novel image-based, patient-specific, fluid-structure computational framework. The geometries of blood, endograft, and aortic wall were reconstructed based on clinical images. Patient-specific measurement data was collected to determine the parameters of the three-element Windkessel. We designed three postoperative scenarios with rigid wall assumption, blood-wall interaction, blood-endograft-wall interplay, respectively, where a two-way fluid-structure interaction (FSI) method was applied to predict the deformation of the composite stentwall. Computational results were validated with Doppler ultrasound data. Results show that the rigid wall assumption fails to predict the waveforms of blood outflow and energy loss (EL). The complete storage and release process of blood flow energy, which consists of four phases is captured by the FSI method. The endograft implantation would weaken the buffer function of the aorta and reduce mean EL by 19.1%. The closed curve area of wall pressure and aortic volume could indicate the EL caused by the interaction between blood flow and wall deformation, which accounts for 68.8% of the total EL. Both the FSI and endograft have a slight effect on wall shear stress-related-indices. The deformability of the composite stent-wall region is remarkably limited by the endograft. Our results highlight the importance of considering the interaction between blood flow, the implanted endograft, and the aortic wall to acquire physiologically accurate hemodynamics in post-TEVAR computational studies and the deformation of the aortic wall is responsible for the major EL of the blood flow.
Within this work, a loosely-coupled high-order fluid-structure interaction (FSI) framework is developed in order to investigate the influence of an elastic panel response on shock-wave/turbulent boundary-layer interac...
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Within this work, a loosely-coupled high-order fluid-structure interaction (FSI) framework is developed in order to investigate the influence of an elastic panel response on shock-wave/turbulent boundary-layer interaction (SWTBLI). Since high-order methods are expected to determine the future of high-fidelity numerical simulations, they are employed in the construction of both fluid and structure solvers. Specifically, a split form arbitrary Lagrangian-Eulerian discontinuous Galerkin spectral element method is employed in the fluid solver and a Legendre spectral finite element method in the structure solver. Shock capturing by an improved adaptive filter method, which confines the filtering effect to the vicinity of shocks, is found to be well-behaved in accuracy, efficiency and *** being validated by two benchmark FSI problems, the developed FSI framework is applied to simulate SWTBLI over an elastic panel. A comparison with a previous simulation of SWTBLI over a rigid panel reveals that: (1) A larger amplitude of the pressure variation, observed on the elastic panel surface, implies a larger threat to the structural integrity;(2) The shock-induced separation flow over the elastic panel changes both in size and shape, leading to a different skin-friction coefficient distribution;(3) A new low-frequency flow unsteadiness of the same magnitude as the elastic panel vibration is detected, which may affect the flow dynamics inside the turbulent boundary layer.& COPY;2023 Elsevier Ltd. All rights reserved.
As the most important component of pool-type fast reactors, the main vessel contains most of the equipment for the primary circuit and thousands of tons of liquid sodium. The fluid-structure interaction effects of the...
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As the most important component of pool-type fast reactors, the main vessel contains most of the equipment for the primary circuit and thousands of tons of liquid sodium. The fluid-structure interaction effects of the coaxial multi-layer thin-walled cylindrical shells formed by the main vessel and its thermal shield cannot be neglected. Though the research on the fluid-structure interaction of the liquid in the pool is sufficient, the research on the short coaxial multi-layer cylindrical shells is not enough, especially the axial and circumferential mode shapes and the ratio of each mode under seismic conditions. So, it is necessary to study the fluid-structure interaction of short coaxial multilayer shells. This paper presents shaking table tests performed on double- and triple-layered cylindrical shells to investigate fluid-structure interaction and seismic response, respectively. The experiments reveal that when the aspect ratio is less than 2, Mode (1,6) exhibits the most significant response under sine wave excitation conditions, while Mode (1,1) demonstrates the highest response under seismic conditions. The first three modes are characterized as out-of-phase modes. Additionally, the pressure component of the first circumferential mode contributes 20% to the overall response of the first 12 modes under seismic conditions.
A numerical approach for the modeling and simulation of fluid-structure interaction (FSI) in multi-material and multi-phase systems with potential phase-changes dynamics is presented. The boundary conditions at the in...
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A numerical approach for the modeling and simulation of fluid-structure interaction (FSI) in multi-material and multi-phase systems with potential phase-changes dynamics is presented. The boundary conditions at the interface between the fluids and structures are enforced using an immersed boundary technique to couple the Eulerian multi-material solver to the Lagrangian structural solver and maintain the solution algorithm's efficiency. The phase-change dynamics are modeled to consider the volume expansion/shrinkage due to the density difference in materials. The algorithm for material phase-change includes a sub-grid model near triple points and benefits from the volume-conservative continuous moment-of-fluid (CMOF) reconstruction method for smooth material domain representation. A systematic stability criterion for the coupled problems with the proposed FSI technique is derived, and the accuracy of the method is verified and tested with multiple canonical problems. The technique is employed to explore the effects of the active vortex generation of a flapping plate on the momentum and thermal dynamics of the nucleate pool boiling phenomenon in a cross-flow in two and three-dimensional setups. (C) 2020 Elsevier Inc. All rights reserved.
An extension of a recently developed quasi-2D flow model for fluid transients in viscoelastic pipes to handle fluid-structure interaction mechanisms is presented. In a context in which the fluid flow is devised as a s...
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An extension of a recently developed quasi-2D flow model for fluid transients in viscoelastic pipes to handle fluid-structure interaction mechanisms is presented. In a context in which the fluid flow is devised as a structured pseudo-mixture and the pipe's viscoelasticity is rooted in an internal variable theory, the axial movement of the pipe wall is allowed to occur, giving rise to friction, Poisson, and junction coupling mechanisms. The resulting governing equations of the model form a quasi-linear hyperbolic system of partial differential equations, which approximated solution is achieved by means of the method of characteristics. The proposed approach is validated against pressure traces acquired from a reservoir-pipe-valve experimental setup found in the literature. In the course of the validating process, different pipe anchoring conditions are employed to study the system responses. Focus is given to pipe-fluid interface interactions, energy dissipation, and transfer of energy between both media. (c) 2023 Elsevier Ltd. All rights reserved.
The static performances of the aerostatic spindles/guideways are significantly affected by the fluid-structure interaction (FSI) effect. However, the existing two-way FSI calculation method for the aerostatic spindles...
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The static performances of the aerostatic spindles/guideways are significantly affected by the fluid-structure interaction (FSI) effect. However, the existing two-way FSI calculation method for the aerostatic spindles and guideways is inefficient. It takes much time to calculate the optimal parameters and static performance in the design and study process. This paper proposes a fast calculation method for the optimal clearance and stiffness of the aerostatic guideway considering FSI, and the calculation process of a cruciform-layout aerostatic guideway was detailed as a case study. Moreover, the accuracy of the proposed fast calculation method is verified numerically and experimentally, which proves that the computational efficiency can be improved dozens or even hundreds of times under the premise of minor calculation errors.
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