A High-Speed Method for the Added Mass in Viscous Fluid and Its Validity
| Autor: | Katsuya, Hirata, Hideki, Shimohara, Shingo, Kikukawa |
|---|---|
| Jazyk: | japonština |
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | 同志社大学理工学研究報告 = The Science and Engineering Review of Doshisha University. 49(1):53-66 |
| ISSN: | 0036-8172 |
| Popis: | 流体工学において、付加質量および仮想質量は、非常に興味深い問題の1つである。本論文では、2次元柱状物体の付加質量係数の高速計算法に関するものである。2次元物体が非圧縮粘性流体中で微小振幅するという仮定の下、full Navier-Stokes方程式を線形近似し、支配方程式がBrinkman方程式になることを利用する。解法は、特異点としてBrinkman方程式の基本解をおいた離散特異点法を用いる。また、離散特異点法の有効性を検証するため、有限差分法を用いてfull Navier-Stokes方程式を解き、正方形柱の結果を離散特異点法の結果と比較する。結果、線形近似の有効範囲を示し、線形近似誤差に関する流れ場の詳細を明らかにした。 In many fluid-structure interaction problems, the virtual mass, namely, the added mass, is one of important concepts. In the present study, we consider a simple method to specify the added-mass coefficients of arbitrary two-dimensional bodies with non-simple cross sections, efficiently and conveniently. Specifically, we consider a two-dimensional incompressible and viscous fluid under the assumption of infinitesimal oscillation amplitude of the body, and properly modify the full Navier-Stokes equations into linear equations, that is, the Brinkman equations. The solving method is based on a discrete singularity method (referred to as DSM), in which we employ a fundamental solution of the Brinkman equations as a singularity. In order to show the method's effectivity and validity, we compute a square cylinder in infinite flow field. Concretely speaking, we solve the full Navier-Stokes equations by a finite difference method (FDM), and compare such solutions with the DSMs. As a result, we reveal the non-linear amplitude effect and specify the valid range of the DSM. |
| Databáze: | OpenAIRE |
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