Stability Analysis of A Partitioned Fluid-Structure Thermal Coupling Algorithm

Author(s):  
Ojas Joshi ◽  
Penelope Leyland
2020 ◽  
Vol 10 (8) ◽  
pp. 2790
Author(s):  
Wenzheng Zhuang ◽  
Chao Yang ◽  
Zhigang Wu

Hybrid corrugated sandwich (HCS) plates have become a promising candidate for novel thermal protection systems (TPS) due to their multi-functionality of load bearing and thermal protection. For hypersonic vehicles, the novel TPS that performs some structural functions is a potential method of saving weight, which is significant in reducing expensive design/manufacture cost. Considering the novel TPS exposed to severe thermal and aerodynamic environments, the mechanical stability of the HCS plates under fluid-structure-thermal coupling is crucial for preliminary design of the TPS. In this paper, an innovative layerwise finite element model of the HCS plates is presented, and coupled fluid-structure-thermal analysis is performed with a parameter study. The proposed method is validated to be accurate and efficient against commercial software simulation. Results have shown that the mechanical instability of the HCS plates can be induced by fluid-structure coupling and further accelerated by thermal effect. The influences of geometric parameters on thermal buckling and dynamic stability present opposite tendencies, indicating a tradeoff is required for the TPS design. The present analytical model and numerical results provide design guidance in the practical application of the novel TPS.


Author(s):  
C. G. Giannopapa ◽  
G. Papadakis

In the conventional approach for fluid-structure interaction problems, the fluid and solid components are treated separately and information is exchanged across their interface. According to the conventional terminology, the current numerical methods can be grouped in two major categories: Partitioned methods and monolithic methods. Both methods use two separate sets of equations for fluid and solid. A unified solution method has been presented [1], which is different from these methods. The new method treats both fluid and solid as a single continuum, thus the whole computational domain is treated as one entity discretised on a single grid. Its behavior is described by a single set of equations, which are solved fully implicitly. In this paper, 2 time marching and one spatial discretisation scheme, widely used for fluids’ equations, are applied for the solution of the equations for solids. Using linear stability analysis, the accuracy and dissipation characteristics of the resulting difference equations are examined. The aforementioned schemes are applied to a transient structural problem (beam bending) and the results compare favorably with available analytic solutions and are consistent with the conclusions of the stability analysis. A parametric investigation using different meshes, time steps and beam sizes is also presented. For all cases examined the numerical solution was stable and robust and proved to be suitable for the next stage of application to full fluid-structure interaction problems.


Author(s):  
Q. Li ◽  
H. Z. Liu ◽  
Z. Zhuang ◽  
S. Yamaguchi ◽  
M. Toyoda

A partitioned coupling algorithm is presented in this paper to solve the dynamic large-displacement fluid-structure interaction (DFSI) problems. In this algorithm, the program based on arbitrary Lagrangian Eulerian (ALE) and fractional two-step method is developed to calculate computational fluid dynamics (CFD) and computational mesh dynamics (CMD). ABAQUS is used to calculate computational structure dynamics (CSD). Some user subroutines are implemented into ABAQUS and the data are exchanged among CSD, CFD and CMD. Numerical results including elephant foot bulging (EFB) of the liquid storage tank are obtained under dynamic waveform.


2008 ◽  
Vol 130 (3) ◽  
Author(s):  
C. G. Giannopapa ◽  
G. Papadakis

In the conventional approach for fluid-structure-interaction problems, the fluid and solid components are treated separately and information is exchanged across their interface. According to the conventional terminology, the current numerical methods can be grouped in two major categories: partitioned methods and monolithic methods. Both methods use separate sets of equations for fluid and solid that have different unknown variables. A unified solution method has been presented in the previous work of Giannopapa and Papadakis (2004, “A New Formulation for Solids Suitable for a Unified Solution Method for Fluid-Structure Interaction Problems,” ASME PVP 2004, San Diego, CA, July, PVP Vol. 491–1, pp. 111–117), which is different from these methods. The new approach treats both fluid and solid as a single continuum; thus, the whole computational domain is treated as one entity discretized on a single grid. Its behavior is described by a single set of equations, which are solved fully implicitly. In this paper, the elastodynamic equations are reformulated so that they contain the same unknowns as the Navier–Stokes equations, namely, velocities and pressure. Two time marching and one spatial discretization scheme, widely used for fluid equations, are applied for the solution of the reformulated equations for solids. Using linear stability analysis, the accuracy and dissipation characteristics of the resulting difference equations are examined. The aforementioned schemes are applied to a transient structural problem (beam bending) and the results compare favorably with available analytic solutions and are consistent with the conclusions of the stability analysis. A parametric investigation using different meshes, time steps, and beam dimensions is also presented. For all cases examined, the numerical solution was stable and robust and therefore is suitable for the next stage of application to full fluid-structure-interaction problems.


2015 ◽  
Vol 07 (02) ◽  
pp. 1550021 ◽  
Author(s):  
Tao He

This paper presents a partitioned strong coupling algorithm for fluid–structure interaction in the arbitrary Lagrangian–Eulerian finite element framework. The incompressible Navier–Stokes equations are solved by the semi-implicit characteristic-based split (CBS) scheme while the structural equations are temporally advanced by the Bathe method. The celled-based smoothed finite element method is adopted for the solution of a geometrically nonlinear solid. To update the dynamic mesh, the moving submesh approach is performed in conjunction with the ortho-semi-torsional spring analogy method. A mass source term is implanted into the pressure Poisson equation to respect the geometric conservation law for the fractional-step-type CBS fluid solver. The iterative solution is achieved by fixed-point method with Aitken's Δ2 accelerator. The proposed methodology is validated against flow-induced oscillations of a bluff body and a flexible body. The overall numerical results agree well with the available data. Some important flow phenomena have been disclosed successfully.


Author(s):  
Takahiro Yamada ◽  
Tomohiro Kayane ◽  
Yoshiaki Itoh ◽  
Ryuko Ootsuka

In this paper, a numerical procedure for interaction problem of largely deformed membrane and fluid is proposed. Numerical computations of deformable structures in viscous flows often encounter numerical instability, which arises from incompatibility of boundary conditions on a fluid-structure interface. In this work, two aspects of compatibility condition including the balance of energy on the fluid-structure interface and the coupling algorithm are discussed and measures to improve attainment of them in numerical procedures are proposed. In this work, a finite difference method with overlapped meshes is employed to solve a fluid problem accurately. For a membrane, a finite element approximation with the energy-momentum method for the temporal discretization is applied to ensure the conservation of energy and unconditional numerical stability. Numerical solutions of these two subsystems are coupled by the block Gauss-Seidel method. Numerical results are given to show numerical properties including stability of the proposed procedure.


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