Asad Mirahky ¹, Fereydoon Pavir ², Mohamad Reza Ansari ²

Affiliations
1 Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, IR
2 Mechanical Engineering Faculty, Sharif University of Technology, Tehran, IR

Abstract

The sloshing of liquid is occurred in a large variety of applications like reservoir containing liquid fuel, Liquefied Natural Gas (LNG), water and etc. In this paper, the critical frequency was found by comparing exciting frequency. The effects of density enhancement on decreasing the amplitude of produced waves and also the pressure imposed on the tank was investigated for various amounts of density. The critical frequency was found by comparing the exciting frequencies of the tank. The gauge pressure imposed on the roof and wall also was investigated in different points. In this paper, the critical areas on where the maximum pressure was applied, is shown. Upper phase density enhancement up to a special point was effective in reduction of sloshing and pressure wave altitude but as this enhancement increases, hydrostatic pressure goes up. The optimum density of the gas phase is p 200 kg3 m m = that reduces the interface sloshing and does not increase the pressure any more.

Keywords

Gas Phase, Resonance, Sloshing, Turbulent Flow

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Fereydoon Pavir ¹, Asad Mirahky ², Mohamad Reza Ansari ³

Affiliations
1 Mechanical Engineering Faculty, Sharif University of Technology, Tehran, IR
2 Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
3 Department of Mechanical Engineering of Tarbiat Modares University, Tehran, Iran

Abstract

Objectives: In this study, sloshing interface in the 2D and 3D tanks were investigated by Open FOAM software Methods/ Statistical Analysis: The obtained results were in good agreement with experimental results. 2D and 3D results that were based on the first natural frequency excitement and ratio of A⁄L<0.1 (stimulation amplitude relative to the length of tank) were very close together. Findings: Rectangular tank with two phase such as gas and liquid was simulated with and without baffle under horizontal excitement in first natural frequency. The torque on the baffle, the height of the liquid in the FS and pressure on the wall of tank for different height of the baffle (installed at the bottom of the tank) were studied. Baffle was mounted in the bottom of the tank, height equal to half the initial height of the liquid. In Previous studies, baffles have been mounted at the liquid part on bottom of tank. In this study, in order to increase efficiency of baffles and reduce the torque exerted on it, baffles were installed in gas part on top wall and only tangent to the surface of liquid in first time. Installing baffles in the roof of tank reduce sloshing, because less torque entered on it in comparison with baffle on bottom of the tank. Application/Improvement: Installed baffles in top of the tank relative to optimum baffle in bottom decreased wave amplitude about 34 percent and exerted torque became half.

Keywords

Sloshing, First Natural Frequency, Baffle

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