scholarly journals Axial Vibration Characteristics of Fluid-Structure Interaction of an Aircraft Hydraulic Pipe Based on Modified Friction Coupling Model

2020 ◽  
Vol 10 (10) ◽  
pp. 3548
Author(s):  
Lingxiao Quan ◽  
Shichao Che ◽  
Changhong Guo ◽  
Haihai Gao ◽  
Meng Guo

This paper aims at studying the axial vibration response characteristics of Fluid-Structure Interaction (FSI) vibration of aircraft hydraulic pipe when considering the friction coupling. Based on the Brunone empirical model and the Zielke weighting function, an expression of fluid shear stress of the hydraulic pipeline is presented for a wide range of Reynolds number, and the friction model of the FSI 14-equation for high-speed and high-pressure hydraulic pipeline is modified. On this basis, a left-wing hydraulic pipeline of the C919 airplane is taken as the verification object and modeled, then the FSI vibration 14-equation is solved using frequency-domain transfer matrix method in MATLAB to analyze the modal and the axial vibration characteristics of the pipeline. Ultimately, a test experiment is given and discussed by being compared with the numerical simulation results, which confirmed the correctness of the friction model and demonstrated that the analytic accuracy of axial velocity response of FSI vibration could be improved by considering the friction coupling.

Author(s):  
Brittany Consuegra ◽  
George T. Flowers

High pressure seals are usually mounted between the rotating and stationary components in high-pressure turbomachinery and often experience intense vibration. These vibrations can interact with the fluid to produce unsteady flows, which can in turn induce structural vibrations that result in machine failure. The reduction of the adverse effects of these vibrations is considered one of the most challenging problems for turbopump design. However, detailed analyses of such fluid-structure interaction problems can be extremely time-consuming and inefficient. The purpose of the present study is to evaluate the effectiveness of simplified, lumped-parameter techniques in analyzing and predicting such behavior, as compared to more sophisticated techniques, with the goal of defining the range of validity for such techniques. A fluid-structure driven vibration is evaluated using a lumped parameter analysis for a wide range of parametric configurations and the results are validated and compared using a bench-top laboratory test rig.


Author(s):  
Riccardo Traversari ◽  
Alessandro Rossi ◽  
Marco Faretra

Pressure losses at the cylinder valves of reciprocating compressors are generally calculated by the classical equation of the flow through an orifice, with flow coefficient determined in steady conditions. Rotational speed has increased in the last decade to reduce compressor physical dimensions, weight and cost. Cylinder valves and associated gas passages became then more and more critical, as they determine specific consumption and throughput. An advanced approach, based on the new Fluid Structure Interaction (FSI) software, which allows to deal simultaneously with thermodynamic, motion and deformation phenomena, was utilized to simulate the complex situation that occurs in a reciprocating compressor cylinder during the motion of the piston. In particular, the pressure loss through valves, ducts and manifolds was investigated. A 3D CFD Model, simulating a cylinder with suction and discharge valves, was developed and experimentally validated. The analysis was performed in transient and turbulent condition, with compressible fluid, utilizing a deformable mesh. The 3D domain simulating the compression chamber was considered variable with the law of motion of the piston and the valve rings mobile according to the fluid dynamic forces acting on them. This procedure is particularly useful for an accurate valve loss evaluation in case of high speed compressors and heavy gases. Also very high pressure cylinders, including LDPE applications, where the ducts are very small and MW close to the water one, can benefit from the new method.


2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham

Abstract The gas-liquid cylindrical cyclone (GLCC©, The University of Tulsa, 1994) is a simple, compact, and low-cost separator, which provides an economically attractive alternative to conventional gravity-based separators over a wide range of applications. The GLCC© inlet section design is a key parameter, which is crucial for its performance and proper operation. An in-depth evaluation of specific design modifications and their effect on safety and structural robustness are carried out in this study using finite element analysis (FEA). Fluid–structure interaction (FSI) analysis is also carried out using the results of computational fluid dynamics (CFD) aimed at investigating the effect of fluid flow on the inlet section structural integrity. The selected design modifications are based on feasibility of GLCC© manufacturing and assembly for field applications. Different case studies incorporating sustained GLCC© internal pressure, dead weight loading, forces generated because of slug flow and high temperatures are analyzed and presented in this paper. The concept of holes cut out in baffle has been effective with no stresses or deformation in the baffle area. FSI simulation of slug flow has proved that FEA direct loading case studies are far more conservative.


2008 ◽  
Vol 9 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Jin-Ho Kim ◽  
Jae-Woo Lee ◽  
Soo-Hyung Park ◽  
Do-Young Byun ◽  
Yung-Hwan Byun ◽  
...  

2020 ◽  
pp. 1-39
Author(s):  
Kushagra Singh ◽  
Farshid Sadeghi ◽  
Thomas Russell ◽  
Steven J. Lorenz ◽  
Wyatt L. Peterson ◽  
...  

Abstract This paper presents a partitioned fluid-structure interaction (FSI) solver to model elastohydrodynamic lubrication (EHL) of line contacts. The FSI model was constructed using the multiphysics simulation software ANSYS wherein an iterative implicit coupling scheme is implemented to facilitate the interaction between fluid and solid components. The model employs a finite volume method (FVM) based computational fluid dynamics (CFD) solver to determine the lubricant flow behavior using the Navier-Stokes equations. Additionally, the finite element method (FEM) is utilized to model the structural response of the solid. Fluid cavitation, compressibility, non-Newtonian lubricant rheology, load balance algorithm and dynamic meshing were incorporated in the FSI model. The pressure and film thickness results obtained from the model are presented for a wide range of loads, speeds, slide to roll ratios (SRR), surface dent, material properties (elastic plastic), etc. The model presents a detailed understanding of EHL contacts by removing any assumptions relative to the Reynolds equation. It provides the (i) two-dimensional variation of pressure, velocity, viscosity etc. in the fluid, and (ii) stress, elastic/plastic strain in the solid, simultaneously. The FSI model is robust, easy to implement and computationally efficient. It provides an effective approach to solve sophisticated EHL problems. The FSI model was used to investigate the effects of surface dents, plasticity and material inclusions under heavily loaded lubricated line contacts as can be found in gears and rolling element bearings. The results from the model exhibit excellent corroboration with published results based on the Reynolds equation solvers.


Author(s):  
Qiyue Lu ◽  
Alfonso Santiago ◽  
Seid Koric ◽  
Paula Cordoba

Abstract Fluid-Structure Interaction (FSI) simulations have applications to a wide range of engineering areas. One popular technique to solve FSI problems is the Arbitrary Lagrangian-Eulerian (ALE) method. Both academic and industry communities developed codes to implement the ALE method. One of them is Alya, a Finite Element Method (FEM) based code developed in Barcelona Supercomputing Center (BSC). By analyzing the application on a simplified artery case and compared to another commercial code, which is Finite Volume Method (FVM) based, this paper discusses the mathematical background of the solver for domains, and carries out verification work on Alya’s FSI capability. The results show that while both codes provide comparable FSI results, Alya has exhibited better robustness due to its Subgrid Scale (SGS) technique for stabilization of convective term and the subsequent numerical treatments. Thus this code opens the door for more extensive use of higher fidelity finite element based FSI methods in future.


2007 ◽  
Vol 17 (06) ◽  
pp. 957-983 ◽  
Author(s):  
A. QUAINI ◽  
A. QUARTERONI

We address the numerical simulation of fluid-structure interaction problems characterized by a strong added-mass effect. We propose a semi-implicit coupling scheme based on an algebraic fractional-step method. The basic idea of a semi-implicit scheme consists in coupling implicitly the added-mass effect, while the other terms (dissipation, convection and geometrical nonlinearities) are treated explicitly. Thanks to this kind of explicit–implicit splitting, computational costs can be reduced (in comparison to fully implicit coupling algorithms) and the scheme remains stable for a wide range of discretization parameters. In this paper we derive this kind of splitting from the algebraic formulation of the coupled fluid-structure problem (after finite-element space discretization). From our knowledge, it is the first time that algebraic fractional step methods, used thus far only for fluid problems in computational domains with rigid boundaries, are applied to fluid-structure problems. In particular, for the specific semi-implicit method presented in this work, we adapt the Yosida scheme to the case of a coupled fluid-structure problem. This scheme relies on an approximate LU block factorization of the matrix obtained after the discretization in time and space of the fluid-structure system. We analyze the numerical performances of this scheme on 2D fluid-structure simulations performed with a simple 1D structure model.


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