scholarly journals Added Mass Effects of Compressible and Incompressible Flows in Fluid-Structure Interaction

2009 ◽  
Vol 76 (2) ◽  
Author(s):  
E. H. van Brummelen
Keyword(s):  
Incompressible Flows ◽  
Fluid Structure Interaction ◽  
Added Mass ◽  
Stability And Convergence ◽  
Time Interval ◽  
Convergence Properties ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Mass Effects ◽  
The Stability

The subiteration method, which forms the basic iterative procedure for solving fluid-structure-interaction problems, is based on a partitioning of the fluid-structure system into a fluidic part and a structural part. In fluid-structure interaction, on short time scales the fluid appears as an added mass to the structural operator, and the stability and convergence properties of the subiteration process depend significantly on the ratio of this apparent added mass to the actual structural mass. In the present paper, we establish that the added-mass effects corresponding to compressible and incompressible flows are fundamentally different. For a model problem, we show that on increasingly small time intervals, the added mass of a compressible flow is proportional to the length of the time interval, whereas the added mass of an incompressible flow approaches a constant. We then consider the implications of this difference in proportionality for the stability and convergence properties of the subiteration process, and for the stability and accuracy of loosely coupled staggered time-integration methods.

Numerical Simulation of Added Mass Effects on a Hydrofoil in Cavitating Flow Using Acoustic Fluid–Structure Interaction

2017 ◽  
Vol 139 (4) ◽  
pp. 041301 ◽  
Author(s):  
Xin Liu ◽  
Lingjiu Zhou ◽  
Xavier Escaler ◽  
Zhengwei Wang ◽  
Yongyao Luo ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fluid Structure Interaction ◽  
Added Mass ◽  
Cavitating Flow ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Mass Effects ◽  
Acoustic Fluid

Natural Frequencies of Centrifugal Compressor Impellers for High Density Gas Applications

2008 ◽  
Author(s):  
Yohei Magara ◽  
Mitsuhiro Narita ◽  
Kazuyuki Yamaguchi ◽  
Naohiko Takahashi ◽  
Tetsuya Kuwano
Keyword(s):  
Centrifugal Compressor ◽  
Natural Frequencies ◽  
Fluid Structure Interaction ◽  
Mass Effect ◽  
Added Mass ◽  
High Density ◽  
Experimental Results ◽  
Density Condition ◽  
Fluid Structure ◽  
Structure Interaction

Characteristics of natural frequencies of an impeller and an equivalent disc were investigated in high-density gas to develop a method for predicting natural frequencies of centrifugal compressor impellers for high-density gas applications. The equivalent disc had outer and inner diameters equal to those of the impeller. We expected that natural frequencies would decrease with increasing the gas density because of the added-mass effect. However, we found experimentally that some natural frequencies of the impeller and the disc in high-density gas decreased but others increased. Moreover, we observed, under high-density condition, some resonance frequencies that we did not observe under low-density condition. These experimental results cannot be explained by only the added-mass effect. For simplicity, we focused on the disc to understand the mechanism of the behavior of natural frequencies. We developed a theoretical analysis of fluid-structure interaction considering not only the mass but also stiffness of gas. The analysis gave a qualitative explanation of the experimental results. In addition, we carried out a fluid-structure interaction analysis using the finite element method. The behavior of natural frequencies of the disc in high-density gas was predicted with errors less than 6%.

scholarly journals Numerical investigation of structural behavior during fluid excited vibrations

2007 ◽  
pp. 491-519
Author(s):  
Saim Yigit ◽  
Michael Schäfer ◽  
Marcus Heck
Keyword(s):  
Incompressible Flows ◽  
Fluid Structure Interaction ◽  
Solution Procedure ◽  
Adequate Treatment ◽  
Fluid Structure ◽  
Flow Solver ◽  
Test Configuration ◽  
Structure Interaction ◽  
Numerical Studies ◽  
Structural Configurations

In the present paper different occurring phenomena during the interaction between certain structural configurations and laminar incompressible flows are investigated. Preliminary investigations concerning the grid movement technique provide the basis for the adequate treatment of the fluid structure interaction problems. Several mechanisms according to real experiments are presented. Systematical numerical studies of material parameters are performed on the basis of a moderately complex fluid structure interaction test configuration. The solution procedure involves the finite-volume flow solver FASTEST, the finite-element structural solver FEAP, and the coupling interface MpCCI.

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