scholarly journals A second-order accurate non-intrusive staggered scheme for the interaction of ultra-lightweight rigid bodies with fluid flow

2020 ◽  
Author(s):  
Chennakesava Kadapa
Keyword(s):  
Incompressible Flows ◽  
Rigid Bodies ◽  
Relaxation Parameter ◽  
Second Order ◽  
Mass Ratio ◽  
Computationally Efficient ◽  
Efficient Scheme ◽  
Staggered Scheme ◽  
Low Mass ◽  
Low Mass Ratio

This paper presents a staggered scheme with second-order temporal accuracy for fluid-structure interaction problems involving ultra-lightweight rigid bodies. The staggered scheme is based on the Dirichlet-Neumann coupling and is non-intrusive. First, the spectral properties of the staggered scheme are studied and also compared against the monolithic scheme using a linear model problem. Later, the suitability and effectiveness of the staggered scheme for problems involving incompressible flows and lightweight rigid solids are illustrated by using the examples of galloping of a square cylinder and lock-in of a circular cylinder for mass-ratio values as low as 0.01. This is the first time in the literature flow-induced vibrations of rigid bodies with such low mass ratio values are successfully simulated using a staggered scheme. Two different fluid solvers are considered to illustrate the non-intrusive nature of the proposed scheme. Guidelines for choosing the relaxation parameter are also provided. With its iteration-free nature and with a single (relaxation) parameter, the proposed staggered scheme renders itself as an accurate and computationally efficient scheme for fluid-rigid body interaction problems, including those involving lightweight structures.

scholarly journals Photometric Analysis of Wide and Narrow Hα Band Observations of R Canis Majoris

1992 ◽  
Vol 151 ◽  
pp. 303-306
Author(s):  
M. Taghi Edalati ◽  
Timothy Banks ◽  
Edwin Budding
Keyword(s):  
Hot Spot ◽  
Optimal Estimate ◽  
Mass Ratio ◽  
Transfer Effects ◽  
Photometric Analysis ◽  
Index Variation ◽  
Algol System ◽  
Low Mass ◽  
Low Mass Ratio ◽  
Optimisation Technique

Wide and narrow Hα lightcurves of R CMa were analysed using Wilson-Devinney (WD) and Information Limit Optimisation Technique (ILOT) approaches. A range of mass ratios, tested by both methods, led to an optimal estimate of around 0.45, at variance with the spectroscopic value. The distortion on the light curve affects the modelling, and so, in a second fitting, this was represented by a ‘hot spot’, associated with mass transfer effects. A semi-detached configuration was then derived. This is supported by the form of the Hα index variation, which has also been modelled. Although thus appearing as a ‘classical Algol’ system, R CMa retains its inherent peculiarity of low mass ratio with low period, which cannot be reconciled with conservative evolution scenarios.

scholarly journals Marginally low mass ratio close binary system V1191 Cyg

New Astronomy ◽  
2012 ◽  
Vol 17 (1) ◽  
pp. 46-49 ◽  
Author(s):  
B. Ulaş ◽  
B. Kalomeni ◽  
V. Keskin ◽  
O. Köse ◽  
K. Yakut
Keyword(s):  
Binary System ◽  
Close Binary System ◽  
Close Binary ◽  
Mass Ratio ◽  
Low Mass ◽  
Low Mass Ratio

scholarly journals Two Contact Binaries with Mass Ratios Close to the Minimum Mass Ratio

2021 ◽  
Vol 922 (2) ◽  
pp. 122
Author(s):  
Kai Li ◽  
Qi-Qi Xia ◽  
Chun-Hwey Kim ◽  
Shao-Ming Hu ◽  
Di-Fu Guo ◽  
...  
Keyword(s):  
Gyration Radius ◽  
Mass Ratio ◽  
Mass Ratios ◽  
Contact Binaries ◽  
Contact Binary ◽  
Low Mass ◽  
Ratio Limit ◽  
Low Mass Ratio ◽  
Diagram Analysis

Abstract The cutoff mass ratio is under debate for contact binaries. In this paper, we present the investigation of two contact binaries with mass ratios close to the low mass ratio limit. It is found that the mass ratios of VSX J082700.8+462850 (hereafter J082700) and 1SWASP J132829.37+555246.1 (hereafter J132829) are both less than 0.1 (q ∼ 0.055 for J082700 and q ∼ 0.089 for J132829). J082700 is a shallow contact binary with a contact degree of ∼19%, and J132829 is a deep contact system with a fill-out factor of ∼70%. The O − C diagram analysis indicated that the two systems manifested long-term period decreases. In addition, J082700 exhibits a cyclic modulation which is more likely resulting from the Applegate mechanism. In order to explore the properties of extremely low mass ratio contact binaries (ELMRCBs), we carried out a statistical analysis on contact binaries with mass ratios of q ≲ 0.1 and discovered that the values of J spin/J orb of three systems are greater than 1/3. Two possible explanations can interpret this phenomenon. One explanation is that some physical processes, unknown to date, are not considered when Hut presented the dynamic stability criterion. The other explanation is that the dimensionless gyration radius (k) should be smaller than the value we used (k 2 = 0.06). We also found that the formation of ELMRCBs possibly has two channels. The study of evolutionary states of ELMRCBs reveals that their evolutionary states are similar with those of normal W UMa contact binaries.

Deep, Low Mass Ratio Overcontact Binary Systems. VI. AH Cancri in the Old Open Cluster M67

2006 ◽  
Vol 131 (6) ◽  
pp. 3028-3039 ◽  
Author(s):  
S.-B. Qian ◽  
L. Liu ◽  
B. Soonthornthum ◽  
L.-Y. Zhu ◽  
J.-J. He
Keyword(s):  
Binary Systems ◽  
Open Cluster ◽  
Mass Ratio ◽  
Low Mass ◽  
Low Mass Ratio

On the nonlinear performance of a tuned sloshing damper under small amplitude excitation

2019 ◽  
Vol 25 (21-22) ◽  
pp. 2695-2705 ◽  
Author(s):  
Anuja Roy ◽  
Zili Zhang ◽  
Aparna (Dey) Ghosh ◽  
Biswajit Basu
Keyword(s):  
Small Amplitude ◽  
Numerical Study ◽  
Nonlinear Behavior ◽  
Wave Theory ◽  
Small Mass ◽  
Mass Ratio ◽  
Hybrid Testing ◽  
Low Mass ◽  
Low Mass Ratio ◽  
Nonlinear Performance

This paper explores the potential of a tuned sloshing damper (TSD) in the control of small amplitude vibrations, which is often important from serviceability considerations, through the use of a relatively small mass ratio of the damper liquid. To investigate the nonlinear behavior of the TSD, real-time hybrid testing is conducted in which a single rectangular tank containing water constitutes the prototype TSD. The structure is modeled as a multi-degree-of-freedom system. Two different base input motions, namely harmonic and synthetically generated broad-banded input, are considered. The sensitivity of the TSD performance to tuning ratio vis-à-vis low mass ratio is studied. The experimental results are compared with those obtained from a numerical study carried out using the shallow water wave theory-based nonlinear, semi-empirical model, for the simulation of the sloshing motion of the TSD liquid (water). Results indicate that in the tuned condition, even with a low mass ratio, the TSD is highly effective in the suppression of the small amplitude vibrations, which is underestimated by the simulation model.

ASAS J083241+2332.4: A NEW EXTREME LOW MASS RATIO OVERCONTACT BINARY SYSTEM

2016 ◽  
Vol 151 (3) ◽  
pp. 69 ◽  
Author(s):  
K. Sriram ◽  
S. Malu ◽  
C. S. Choi ◽  
P. Vivekananda Rao
Keyword(s):  
Binary System ◽  
Mass Ratio ◽  
Low Mass ◽  
Low Mass Ratio
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