The role of added mass in the theory of Hele-Shaw cell bubbles

1988 ◽  
Vol 39 (3) ◽  
pp. 441-446
Author(s):  
Peder A. Tyvand
Keyword(s):  
Added Mass ◽  
Hele Shaw Cell

scholarly journals On the role of added mass and vorticity release for self-propelled aquatic locomotion

2021 ◽  
Vol 918 ◽  
Author(s):  
D. Paniccia ◽  
G. Graziani ◽  
C. Lugni ◽  
R. Piva
Keyword(s):  
Added Mass ◽  
Aquatic Locomotion

Abstract

Illuminating the complex role of the added mass during vortex induced vibration

2021 ◽  
Vol 33 (8) ◽  
pp. 085120
Author(s):  
Zhicheng Wang ◽  
Dixia Fan ◽  
Michael S. Triantafyllou
Keyword(s):  
Added Mass ◽  
Vortex Induced Vibration

Unsteady swimming of small organisms

2012 ◽  
Vol 702 ◽  
pp. 286-297 ◽  
Author(s):  
S. Wang ◽  
A. M. Ardekani
Keyword(s):  
Reynolds Number ◽  
Low Reynolds Number ◽  
Fundamental Equation ◽  
Added Mass ◽  
Natural Environments ◽  
Mean Velocity ◽  
Unsteady Forces ◽  
Uniform Background ◽  
Low Reynolds

AbstractSmall planktonic organisms ubiquitously display unsteady or impulsive motion to attack a prey or escape a predator in natural environments. Despite this, the role of unsteady forces such as history and added mass forces on the low-Reynolds-number propulsion of small organisms, e.g. Paramecium, is poorly understood. In this paper, we derive the fundamental equation of motion for an organism swimming by means of the surface distortion in a non-uniform background flow field at a low-Reynolds-number regime. We show that the history and added mass forces are important as the product of Reynolds number and Strouhal number increases above unity. Our results for an unsteady squirmer show that unsteady inertial effects can lead to a non-zero mean velocity for the cases with zero streaming parameters, which have zero mean velocity in the absence of inertia.

scholarly journals Drag cancellation by added-mass pumping

2016 ◽  
Vol 798 ◽  
Author(s):  
F. Giorgio-Serchi ◽  
G. D. Weymouth
Keyword(s):  
Shape Change ◽  
Stokes Number ◽  
Added Mass ◽  
Navier Stokes ◽  
Viscous Damping ◽  
Size Change ◽  
Biologically Inspired ◽  
Sustained Oscillations ◽  
Submerged Body

A submerged body subject to a sudden shape change experiences large forces due to the variation of added-mass energy. While this phenomenon has been studied for single actuation events, application to sustained propulsion requires the study of periodic shape change. We do so in this work by investigating a spring–mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. We develop an analytical model to investigate the relationship between added-mass variation and viscous damping, and demonstrate its range of application with fully coupled fluid–solid Navier–Stokes simulations at large Stokes number. Our results demonstrate that the recovery of added-mass kinetic energy can be used to completely cancel the viscous damping of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius $r_{0}$. A quasi-linear relationship is found to link the terminal amplitude of the oscillations $X$ to the extent of size change $a$, with $X/a$ peaking at values from 4 to 4.75 depending on the details of the shape-change kinematics. In addition, it is found that pumping in the frequency range of $1-a/2r_{0}<{\it\omega}^{2}/{\it\omega}_{n}^{2}<1+a/2r_{0}$, with ${\it\omega}/{\it\omega}_{n}$ being the ratio between frequency of actuation and natural frequency, is required for sustained oscillations. The results of this analysis shed light on the role of added-mass recovery in the context of shape-changing bodies and biologically inspired underwater vehicles.

Adhesion and fingering in the lifting Hele-Shaw cell: Role of the substrate

2008 ◽  
Vol 25 (3) ◽  
pp. 267-275 ◽  
Author(s):  
S. Sinha ◽  
T. Dutta ◽  
S. Tarafdar
Keyword(s):  
Hele Shaw Cell

Miscible quarter five-spot displacements in a Hele-Shaw cell and the role of flow-induced dispersion

1999 ◽  
Vol 11 (7) ◽  
pp. 1705-1716 ◽  
Author(s):  
Philippe Petitjeans ◽  
Ching-Yao Chen ◽  
Eckart Meiburg ◽  
Tony Maxworthy
Keyword(s):  
Hele Shaw Cell

Study on Influence of the Truss Bridge’s Nature Frequency by Added Masses

2012 ◽  
Vol 178-181 ◽  
pp. 2140-2143
Author(s):  
Xiang Lin Jiang ◽  
Dong Bing Zhang ◽  
Guo Liang Zen
Keyword(s):  
Natural Frequency ◽  
Added Mass ◽  
Bridge Monitoring ◽  
Large Span ◽  
Steel Truss Bridge ◽  
Bridge Model ◽  
Added Masses ◽  
Nature Frequency ◽  
Truss Bridge

Due to the role of the vehicle, the large-span bridge’s frequency which is according to the bridge monitoring data is actually the vibration frequency of the vehicle-bridge coupled vibration system, but not the bridge’s natural frequency. This paper gets formulation of the added mass and the beam’s natural frequency according to the added mass of the beam’s vibration equation; and the formulation is tested by experiments and numerical simulation of a large-span steel truss bridge model. Result shows that added masses which have the fixed location are linearly proportional to changing values of the bridge’s nature frequency.

Hydrodynamic Added Mass and Damping of the Kaplan Turbine

2011 ◽  
Author(s):  
Jyrki M. Keto-Tokoi ◽  
Jerzy E. Matusiak ◽  
Erno K. Keskinen
Keyword(s):  
Water Flow ◽  
Added Mass ◽  
The Finite Element Method ◽  
Inertia Effects ◽  
Shaft Line ◽  
Kaplan Turbine ◽  
Circulatory Effects ◽  
Turbine Runner ◽  
Turbine Shaft

Kaplan turbine runner rotates in water flow inside an enclosed discharge ring. The vibratory runner motion in the fluid flow induces pressure forces onto the wet runner surfaces with inertia effects conveniently described by the so-called hydrodynamic added mass and damping. These inertia effects influence the wet natural frequencies and the amplitudes. The role of the hydrodynamic added mass and damping in the Kaplan turbine shaft rotor dynamics has not been sufficiently well understood. This paper focuses on comprehensive understanding of these phenomena across the Kaplan design range. The results are based on a method derived from Theodorsen’s unsteady thin airfoil theory and on the Finite Element Method (FEM). The former method includes the water flow, the runner rotation and the circulatory effects, which makes it possible to calculate the added damping and evaluate the accuracy of FEM. The most critical vibration modes and shaft line configurations have been identified with inherent weaknesses in typical shaft line models. The added damping has been quantified. The numerical results have been compared to the experimental results.

scholarly journals The role of added mass in the dispersion of bubble clouds

2019 ◽  
Vol 240 ◽  
pp. 062050
Author(s):  
S. Zoghlami ◽  
C. Béguin ◽  
S. Etienne ◽  
D. Scott ◽  
L. Bornard
Keyword(s):  
Added Mass ◽  
Bubble Clouds
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