Dynamic Characteristics of Liquid Motion in Partially Filled tanks of Spinning Spacecraft
Authors
Agrawal, B.N.
Subjects
Advisors
Date of Issue
1990
Date
April 5-6, 1990
Publisher
Language
Abstract
This paper presents a boundary layer model to predict dynamic characteristics of liquid motion in partially filled tanks of a spinning spacecraft. The solution is obtained by solving three boundary value problems: inviscid, the boundary layer, and viscous correction. This boundary layer solution is obtained analytically, and the inviscid and viscous correction solutions are obtained by using finite element methods. This model has been used to predict liquid natural frequencies, mode shapes, damping ratios, and nutation time constants for the INTELSAT VI spacecraft. The analytical results were compared with experimental results and are in good agreement. The results show that liquid motion in general will contain significant circulatory motion due to Coriolis forces except in the first azimuth and first elevation modes. Therefore, only these two modes can be represented accurately by equivalent pendulum models. The analytical results predict a sharp drop in nutation time constants for certain inertia ratios and tank fill fractions. This phenomenon, known as anomalous resonance, was also present during INTELSAT IV in-orbit liquid slosh tests and ground air bearing tests for INTELSAT IV and VI.
This paper presents a boundary layer model to predict dynamic characteristics of liquid motion in partially filled tanks of a spinning spacecraft. The solution is obtained by solving three boundary value problems: inviscid, the boundary layer, and viscous correction. This boundary layer solution is obtained analytically, and the inviscid and viscous correction solutions are obtained by using finite element methods. This model has been used to predict liquid natural frequencies, mode shapes, damping ratios, and nutation time constants for the INTELSAT VI spacecraft. The analytical results were compared with experimental results and are in good agreement. The results show that liquid motion in general will contain significant circulatory motion due to Coriolis forces except in the first azimuth and first elevation modes. Therefore, only these two modes can be represented accurately by equivalent pendulum models. The analytical results predict a sharp drop in nutation time constants for certain inertia ratios and tank fill fractions. This phenomenon, known as anomalous resonance, was also present during INTELSAT IV in-orbit liquid slosh tests and ground air bearing tests for INTELSAT IV and VI.
This paper presents a boundary layer model to predict dynamic characteristics of liquid motion in partially filled tanks of a spinning spacecraft. The solution is obtained by solving three boundary value problems: inviscid, the boundary layer, and viscous correction. This boundary layer solution is obtained analytically, and the inviscid and viscous correction solutions are obtained by using finite element methods. This model has been used to predict liquid natural frequencies, mode shapes, damping ratios, and nutation time constants for the INTELSAT VI spacecraft. The analytical results were compared with experimental results and are in good agreement. The results show that liquid motion in general will contain significant circulatory motion due to Coriolis forces except in the first azimuth and first elevation modes. Therefore, only these two modes can be represented accurately by equivalent pendulum models. The analytical results predict a sharp drop in nutation time constants for certain inertia ratios and tank fill fractions. This phenomenon, known as anomalous resonance, was also present during INTELSAT IV in-orbit liquid slosh tests and ground air bearing tests for INTELSAT IV and VI.
This paper presents a boundary layer model to predict dynamic characteristics of liquid motion in partially filled tanks of a spinning spacecraft. The solution is obtained by solving three boundary value problems: inviscid, the boundary layer, and viscous correction. This boundary layer solution is obtained analytically, and the inviscid and viscous correction solutions are obtained by using finite element methods. This model has been used to predict liquid natural frequencies, mode shapes, damping ratios, and nutation time constants for the INTELSAT VI spacecraft. The analytical results were compared with experimental results and are in good agreement. The results show that liquid motion in general will contain significant circulatory motion due to Coriolis forces except in the first azimuth and first elevation modes. Therefore, only these two modes can be represented accurately by equivalent pendulum models. The analytical results predict a sharp drop in nutation time constants for certain inertia ratios and tank fill fractions. This phenomenon, known as anomalous resonance, was also present during INTELSAT IV in-orbit liquid slosh tests and ground air bearing tests for INTELSAT IV and VI.
This paper presents a boundary layer model to predict dynamic characteristics of liquid motion in partially filled tanks of a spinning spacecraft. The solution is obtained by solving three boundary value problems: inviscid, the boundary layer, and viscous correction. This boundary layer solution is obtained analytically, and the inviscid and viscous correction solutions are obtained by using finite element methods. This model has been used to predict liquid natural frequencies, mode shapes, damping ratios, and nutation time constants for the INTELSAT VI spacecraft. The analytical results were compared with experimental results and are in good agreement. The results show that liquid motion in general will contain significant circulatory motion due to Coriolis forces except in the first azimuth and first elevation modes. Therefore, only these two modes can be represented accurately by equivalent pendulum models. The analytical results predict a sharp drop in nutation time constants for certain inertia ratios and tank fill fractions. This phenomenon, known as anomalous resonance, was also present during INTELSAT IV in-orbit liquid slosh tests and ground air bearing tests for INTELSAT IV and VI.
This paper presents a boundary layer model to predict dynamic characteristics of liquid motion in partially filled tanks of a spinning spacecraft. The solution is obtained by solving three boundary value problems: inviscid, the boundary layer, and viscous correction. This boundary layer solution is obtained analytically, and the inviscid and viscous correction solutions are obtained by using finite element methods. This model has been used to predict liquid natural frequencies, mode shapes, damping ratios, and nutation time constants for the INTELSAT VI spacecraft. The analytical results were compared with experimental results and are in good agreement. The results show that liquid motion in general will contain significant circulatory motion due to Coriolis forces except in the first azimuth and first elevation modes. Therefore, only these two modes can be represented accurately by equivalent pendulum models. The analytical results predict a sharp drop in nutation time constants for certain inertia ratios and tank fill fractions. This phenomenon, known as anomalous resonance, was also present during INTELSAT IV in-orbit liquid slosh tests and ground air bearing tests for INTELSAT IV and VI.
Type
Conference Paper
Description
The article of record as published may be found at http://dx.doi.org/10.2514/6.1990-997
Series/Report No
Organization
Spacecraft Research and Design Center (SRDC)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Proceedings of 31st AIAA/ASME/ASCE/AHS/AHC Structures, Structural Dynamics and Materials Conference, Long Beach, CA, April 5-6, 1990.
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined
in Title 17, United States Code, Section 101. As such, it is in the
public domain, and under the provisions of Title 17, United States
Code, Section 105, is not copyrighted in the U.S.