Showing 5 results for Fluid-Solid Interaction
Hadi Etemadi, Mohammad Fathalilou, Rasool Shabani, Ghader Rezazadeh,
Volume 17, Issue 1 (3-2017)
Abstract
In this paper, the fluid- solid interaction in an electrostatic microbeam by using three- dimensional aerodynamic theory has been studied. Modified couple stress theory is used to model the elasticity depends on the size of the microbeam. The proposed model can be used as a mass micro- sensor. To analyze the dynamic behavior of the microbeam a DC voltage applied to the system and then by applying an AC voltage dynamic characteristics of the system around static deformed condition is analyzed. Because of non-linear nature of the governing equations to solve them reduced order model based on Galerkin is used. Results have shown that considering the couple stress and also increase the size of the length characteristic parameter reduces the size of the fluid pressure differential created between the two sides of the microbeam. However, according to the three- dimensional aerodynamic theory for fluid-solid interaction, change of the pressure difference created does not lead to creation difference in predicting the size of the added mass between the classical and modified couple stress theories. In another part of the results has been shown that the presence of added mass to what extent can makes changes in the frequency response curves drawn for the system. Also applied the couple stress theory and increase the size of the length characteristic parameter makes the system more rigid and consequently reduce the amplitude of the vibration and frequency response curves shift to the right.
Behzad Seyfi, Nasser Fatouraee, Abbas Samani,
Volume 17, Issue 7 (9-2017)
Abstract
Adipose tissue is a loose connective tissue distributed in two main anatomic depots including subcutaneous and visceral. Since in many pathological condition and diseases associated with adipose tissue alteration, the micro-components of adipose tissue undergoes considerable changes from mechanical characteristics point of view, it is quite vital to present an accurate structural technique for modelling tissue microstructure. Accordingly, this paper presents a structural model based on adipose tissue main components and interaction between them. Adipocytes was considered as a fluidic spheres and extracellular matrix modeled as solid media. The interaction between these two different phases simulated by solving well-known fluid-structure interaction (FSI) problem. In order to obtain the constitutive parameters for ECM, finite element simulation results fitted to experimental uniaxial compression test data. To make a comparison between the performances of different constitutive models, three conventional hyperelastic models were used for describing the mechanical behavior of ECM. The agreement between experimental data and simulation results confirm that the presented technique has a high potential for modeling adipose tissue microstructure both in normal and pathological condition. Considering the accuracy and mathematical complexity, results show that Yeoh hyperelastic model has a better performance than two others. In all three model, results reveals that the stiffness of adipose tissue ECM is ~ (2-3) times higher than that of the adipose tissue.
M.h. Shojaeifard, A. Sajedin, A. Khalkhali,
Volume 19, Issue 11 (11-2019)
Abstract
Turbocharger turbine blade thickness is restricted by blockage and trailing edge losses and it is exposed to damage due to aerodynamic loads. Proper designing of the blade needs to full recognition of loads on the blade. Therefore, the force from the fluid to the blade should be calculated. Although, thickening the blade results to the more resistance to fracture and cracks, but it affects the aero-structural performance of each section of the blade differently. So, turbocharger turbine blades are exposed to pulsating flow which should be considered in thickness distribution selection. This article reports a comprehensive fluid-solid interaction study of the turbine blades with different thickness distribution which could beneficially investigates the effect of each part thickness on the aerostatic efficiency. Leading edge and trailing edge thickness, maximum thickness and its location, trailing edge shape, hub, and tip blade thickness were the variables which their effects were investigated. Using dual turbocharger turbines leads to lower dissipation of kinetic energy of pulsating charge from the engine. In such turbines, each sector of rotor accepts a different charge from upper and lower entries. The flow distribution of every passage is the difference from the others. Therefore, to the evaluation of the flow, modeling of the entire turbine is needed. 3D CFD model in ANSYS CFX for fluid side and an FEA model in ANSYS Static Structural module for the blade structural responses were used then the results were coupled. Validation was performed by reference to experimental data carried out in imperial college London on a dual turbocharger turbine.
Mohamed Javad Farahmand , Ali Hassani, Ali Moazemi Goudarzi,
Volume 21, Issue 9 (9-2021)
Abstract
In present study, the stress and strain distributions due to the radiant gradient in some radiant tube burners have been investigated. In the design of the burner, several outlet valves are mounted on the wall of the burner tube and the combustion-produced fluid is discharged by the outlets into the furnace. For this purpose, three cylindrical radiant tubes with the same length, diameter, thickness and material and difference in design of fluid outlets are modeled. To simulate the mechanical behavior of the pipes, after the geometric modeling and considering the pipe material and boundary conditions, ANSYS commercial software has been used. The boundary conditions for numerical solution are extracted from the results of the experimental tests. Due to the average fluid velocity within the radial tube, the fluid flow falls into the turbulent range. In order to obtain the stress-strain diagram of the tested alloy, the Ramberg-Osgood equation is used. Due to the solution of the fluid-solid interaction by ANSYS, the best design is concluded through the Von-Mises stress minimum values. Also, by removing the thermal load from the next load step, the residual stresses generated in the samples are calculated. To illustrate the accuracy of the solution, some specimens of the burner have been made and evaluated to verify the numerical solution.
Mojtaba Haghgoo, Hashem Babaei, Tohid Mirzababaie Mostofi,
Volume 21, Issue 11 (9-2021)
Abstract
Numerical simulation of Eulerian fluid Lagrangian solid interaction incorporating H2-O2 mixture gas detonation plate forming by employing conservative element and solution element immersed boundary method in LS-DYNA software is proposed in this paper. The detonation mechanism includes 7 species and 16 reactions. The chemical reaction mechanism and detonation wave propagation of Eulerian solver and dynamic plastic response of mild steel thin plate of Lagrangian solver are discussed thoroughly. The Johnson-Cook phenomenological material model with failure criterion is used to provide accurate predictions of dynamic response and failure state of detonation loaded steel plates taking into account material strain-rate sensitivity and non-linearities. The 2D numerical model is validated by comparing the simulation results with experimental data for thickness strain. The simulated pressure-time history of combustion cylinder, von Mises stress and deflection pattern of plate are also represented. Furthermore, a series of numerical simulation was carried out to determine the effect of the magnitude of internal detonation pressure on plate, taking into account different combustion cylinder longitudinal capacities, pre-detonation pressures and ignition point locations. Results show that an increase of pre-detonation pressure is conducive to increase the value of maximum detonation pressure while decreasing the combustion duration. Moreover, combustion cylinder with higher longitudinal capacity is more powerful to deform the plate.
