Browsing by Author "Sahaj, K.V."

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Effectiveness of porous baffle on resonance sloshing motion: An experimental study
(American Institute of Physics Inc., 2023) Sahaj, K.V.; Nasar, T.
Liquid movement in tanks that is partially filled can cause large structural loads if the tank movement is near the natural period of fluid within the tank. Sloshing implies the movement of a free liquid surface inside a vessel. A shake-Table experiment for various depths of water of aspect ratio 0.163, 0.325, and 0.488 are investigated to examine the effect of sloshing. The frequencies of excitation range from 0.4566 Hz to 1.9757 Hz which covers up to the fifth mode sloshing frequency and a constant amplitude of 7.5mm is adopted. A single porous at l/2 location is considered to check its effectiveness in comparison with the unbaffled condition. Three different porosities of 15%, 20%, and 25 % are adopted. Capacitance wave probes are used to record the free surface elevation at the end walls. The results of maximum free surface elevation (Î·max) and spectral moments (mo) are present here. The suppression of resonant sloshing motion by porous baffle is analyzed. A higher sloshing oscillation is observed for the aspect ratio (hs/l) of 0.325 than compared with the other two fill levels. Â© 2023 Author(s).
Experimental Study on Liquid Sloshing Dynamics in a Sway Excited Rectangular Tank
(Springer Science and Business Media Deutschland GmbH, 2024) Sahaj, K.V.; Shri, S.; Nasar, T.
An experimental shake table program is performed to explore the hydrodynamic behavior of liquid sloshing phenomena in a partially filled rectangular tank of 1:43 scaled tank subjected to sway excitation. Three different aspect ratios (hs/l, liquid depth, hs to the length of the tank, l) of 0.163, 0.325 and 0.488 which corresponds to 25%, 50% and 75% fill depths are considered. Excitation parameters such as frequencies ranging from 0.45 to 3.2Â Hz which encompasses up to fifth mode of sloshing frequency and amplitudes of 4 and 8Â mm are considered. An experimental setup is designed and devised to measure the sloshing force by using ballast mass concept. The experimental parameters such as run-up of sloshing oscillation, sloshing force and spectral energy are discussed. Experimental results of sloshing oscillation are compared with the numerical works of Nasar et al. (J Nav Archit Mar Eng 9:43â€“65, 2012). The present study reveals that the effect of excitation on sloshing oscillation is more pronounced near first mode of resonance and insignificant at off-resonance conditions. The effect of excitation amplitude on the fill level is pronounced in the order of 50, 25 and 75% fill levels on sloshing oscillation, sloshing force and spectral energy. The sloshing force is found to be about 9.32, 26.03 and 26.43Â N for the excitation parameters of forcing frequency (f) that equals to first mode sloshing frequency (f1) and amplitude of excitation Aâ€‰=â€‰8Â mm. The sloshing tank with 75% fill depth experiences more sloshing force on its containment than 25 and 50% fill depths. Â© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
Experimental study on liquid sloshing with dual vertical porous baffles in a sway excited tank
(Techno-Press, 2021) Sahaj, K.V.; Nasar, T.; Vijay, K.G.
Sloshing behavior of liquid within containers represents one of the most fundamental fluid-structure interactions. Liquid in partially filled tanks tends to slosh when subjected to external disturbances. Sloshing is a vicious resonant fluid motion in a moving tank. To understand the effect of baffle positioned at L/3 and 2L/3 location, a shake table experiments was conducted for different fill volumes of aspect ratio 0.163, 0.325 and 0.488. For a fixed amplitude of 7.5 mm, the excitation frequencies are varied between 0.457 Hz to 1.976 Hz. Wave probes have been located at both tank ends to capture the surface elevation. The experimental parameters such as sloshing oscillation and energy dissipation are discussed here. Comparison is done for with baffles and without baffles conditions. For both conditions, the results showed that aspect ratio of 0.163 gives better surface elevation and energy dissipation than obtained for aspect ratio 0.325 and 0.488. Good agreement is observed when numerical analysis is compared with the experiments results. © 2021 Techno-Press, Ltd
Sloshing Dynamics in Sway Excited Rectangular Scaled Tanks; 横荡激励下矩形缩比罐中的液体晃动力学
(Editorial Board of Journal of Harbin Engineering, 2023) Sahaj, K.V.; Shri, S.; Nasar, T.
The present paper presents the sloshing oscillation behaviour and sloshing force in three different tanks of model scales of 1:86, 1:57 and 1:43. The rectangular tank is mounted on shake table, to study the scale effect of sloshing with sway excited motion. The tests are carried out for the aspect ratio (hs/l, where hs liquid depth and l is the length of the tank) of 0.162 5, 0.325, and 0.487 5 which represents 25%, 50% and 75% of liquid fill levels, respectively. Seventeen excitation frequencies ranging from 0.456 6 Hz to 1.975 7 Hz are considered, which covers up to the fifth sloshing mode. The sloshing oscillations occurs in the longitudinal axis when subjected to sway excitations. An experimental setup is designed and devised to measure sloshing force by the concept of ballast mass. The inertia forces are measured by load cells and sloshing oscillation time histories are measured by capacitance probes. It is found that violent sloshing is experienced for 50% filled condition irrespective of scaled tanks, excitation amplitudes and excitation frequencies. The sloshing force is maximum in 1:43 scaled tank than other scaled sloshing tanks irrespective of the excitation frequency and amplitude for 50% fill level. Based on the experimental observations and analysis of results, it is concluded that proportionate volume of water and tank size decides the severity of sloshing in the partially filled tanks. © 2023, Harbin Engineering University and Springer-Verlag GmbH Germany, part of Springer Nature.