Dynamics of Liquid Sloshing in Upright and Inverted Bladdered Tanks

1987 ◽  
Vol 109 (1) ◽  
pp. 58-63 ◽  
Author(s):  
F. T. Dodge ◽  
D. D. Kana
Keyword(s):  
Structural Dynamics ◽  
Mechanical Model ◽  
The Body ◽  
Liquid Sloshing ◽  
Model Parameters ◽  
Test Results ◽  
Governing Equations ◽  
Low Gravity ◽  
Equivalent Mechanical Model ◽  
Mechanical Models

The sloshing of liquids in tanks that use a flexible, inextensible bladder to contain the liquid is investigated experimentally and theoretically. The bladder affects both the configuration of the liquid in the tank and the sloshing frequencies and motion. The governing equations of liquid sloshing coupled to the structural dynamics of the bladder are formulated and examined to determine the interaction between the body forces of the liquid and the stiffness of the bladder and to show that the slosh dynamics can be represented by equivalent mechanical models. Tests are conducted to establish such mechanical models for normal and low-gravity conditions. For an inverted tank (liquid above the bladder), the sloshing is sufficiently different from conventional sloshing that the form of the equivalent mechanical model as well as the numerical values of the model parameters must be derived from the test results.

Experimental and Theoretical Studies of Liquid Sloshing at Simulated Low Gravity

1967 ◽  
Vol 34 (3) ◽  
pp. 555-562 ◽  
Author(s):  
F. T. Dodge ◽  
L. R. Garza
Keyword(s):  
Natural Frequency ◽  
Mechanical Model ◽  
Small Diameter ◽  
Bond Number ◽  
Liquid Sloshing ◽  
Theoretical Studies ◽  
Low Gravity ◽  
Equivalent Mechanical Model ◽  
Experimental And Theoretical Studies ◽  
Experimental Comparisons

Analyses and experimental comparisons are given for liquid sloshing in a rigid cylindrical tank under conditions of moderately small axial accelerations; in particular, the theory is valid for Bond numbers larger than 10. The analytical results are put in the form of an equivalent mechanical model, and it is shown that the sloshing mass and the natural frequency of the first mode, for a liquid having a 0 deg contact angle at the tank walls, are smaller than for high-g conditions. The experimental data, obtained by using several small-diameter tanks and three different liquids, are compared to the predictions of the mechanical model; good correlation is found in most cases for the sloshing forces and natural frequency as a function of Bond number.

Parameter Computation of Equivalent Mechanical Models of Liquid Sloshing in Spacecraft Container

2013 ◽  
Vol 397-400 ◽  
pp. 209-212 ◽  
Author(s):  
Li Xin Zhang ◽  
Zheng Feng Bai ◽  
Yang Zhao ◽  
Xi Bin Cao
Keyword(s):  
Mechanical Model ◽  
Liquid Sloshing ◽  
Equivalent Model ◽  
Parameter Determination ◽  
Mass Model ◽  
Numerical Example ◽  
Equivalent Mechanical Model ◽  
Determination Process ◽  
Pendulum Model ◽  
Mechanical Models

Liquid sloshing is the source of disturbance. General the equivalent mechanical models are used to simulate the liquid sloshing in container. In this paper, the equivalent pendulum model for liquid sloshing is established. Further, the parameter relationship between the equivalent spring-mass model and equivalent pendulum model is presented. Then, parameter determination process of the equivalent mechanical model is proposed. Finally, a numerical example is implemented to calculate the parameters of equivalent model for liquid sloshing in a container.

scholarly journals Dynamics Modelling and Simulation for Deployment Characteristics of Mesh Reflector Antennas

2020 ◽  
Vol 10 (21) ◽  
pp. 7884
Author(s):  
Xin Jiang ◽  
Zhengfeng Bai
Keyword(s):  
Large Deformation ◽  
Mechanical Model ◽  
Numerical Procedure ◽  
Modelling And Simulation ◽  
Governing Equations ◽  
Precise Description ◽  
Reflector Antennas ◽  
Equivalent Mechanical Model ◽  
Dynamics Modelling ◽  
Large Motion

The dynamics of mesh reflectors are characterized by large deformation when antennas undergo a large motion in the deployment process. In this work, absolute node coordinate formulation (ANCF), with the merit of precise description of large deformation, is employed to consider the flexibility of the reflector net. From a practical perspective, the effect of the torsional spring is incorporated into the dynamic governing equations by an equivalent mechanical model. Deployment simulation of the mesh reflector antennas is performed by a numerical procedure. It can be found that with the action of a degenerative driven force caused by the friction effect, the deployed process of antennas exhibits a character of asynchronous deployment. Additionally, a significant increase in tension during the final period of deployment has an intense influence on smooth deployment.

Equivalent mechanical model for liquid sloshing during draining

2011 ◽  
Vol 68 (1-2) ◽  
pp. 91-100 ◽  
Author(s):  
Qing Li ◽  
Xingrui Ma ◽  
Tianshu Wang
Keyword(s):  
Mechanical Model ◽  
Liquid Sloshing ◽  
Equivalent Mechanical Model

Mechanical Models of Low-Gravity Sloshing Taking Into Account Viscous Damping

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
M. Utsumi
Keyword(s):  
Surface Tension ◽  
Mechanical Model ◽  
Damping Ratio ◽  
Space Vehicle ◽  
Control Analysis ◽  
Phase Lag ◽  
Low Gravity ◽  
Correction Model ◽  
Mechanical Models ◽  
Modal Equation

Mechanical models of damped low-gravity sloshing are developed using a proposed analytical method for arbitrary axisymmetric tanks. It is shown that (a) the complex amplitudes of the force and moment caused by the conventional mechanical model do not coincide with the complex amplitudes of the force and moment calculated from the modal equation of sloshing and (b) these differences arise not only from the damping ratio but also from the surface tension although the surface tension does not cause energy dissipation. A mechanical model for correcting these differences is developed. The mass of this correction model is found to be equal to the mass of the liquid that fills the domain bounded by the meniscus and the plane that includes the contact line of the meniscus with the tank wall. With decreasing Bond number, the correction model mass as well as the damping ratio increase and, therefore, the correction becomes important. The force and moment caused by the conventional uncorrected mechanical model have phase lag with respect to the force and moment calculated from the modal equation of sloshing near the resonant frequency. Therefore, the correction is important for the dynamics and control analysis of a space vehicle.

scholarly journals Equivalent Mechanical Model for Lateral Liquid Sloshing in Partially Filled Tank Vehicles

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Zheng Xue-lian ◽  
Li Xian-sheng ◽  
Ren Yuan-yuan
Keyword(s):  
Cross Sections ◽  
Mechanical Model ◽  
Dynamic Effect ◽  
Liquid Sloshing ◽  
Lateral Acceleration ◽  
New Approach ◽  
Roll Control ◽  
Equivalent Mechanical Model ◽  
Parameter Values ◽  
Tank Vehicles

This paper reports a new approach to investigating sloshing forces and moments caused by liquid sloshing within partially filled tank vehicles subjected to lateral excitations. An equivalent mechanical model is used in the paper to approximately simulate liquid sloshing. The mechanical model is derived by calculating the trajectory of the center of gravity of the liquid bulk in tanks as the vehicle’s lateral acceleration changes from 0 to 1 g. Parametric expressions for the model are obtained by matching the dynamic effect of the mechanical model to that of liquid sloshing. And parameter values of a liquid sloshing dynamic effect, such as sloshing frequency and forces, are acquired using FLUENT to simulate liquid sloshing in tanks with different cross-sections and liquid fill percentages. The equivalent mechanical model for liquid sloshing in tank vehicles is of a great significance for simplifying the research on roll stability of tank vehicles and for developing active/passive roll control systems for these vehicles.

Sign in / Sign up

Export Citation Format

Share Document