Experimental Investigation on the Dynamic Characteristics of a Concentric Membrane Tank

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 16560693
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Aerospace engineering
• Research Institution: Japan Aerospace Exploration Agency
• Principal Investigator: KOMATSU Keiji Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science Department of Space Structure and Materials, 宇宙科学研究本部宇宙構造・材料工学研究系, 教授 (20358683)
• Project Period (FY): 2004 – 2006
• Keywords: sloshing / vibration / membrane / tank / concentric / hydroelasticity / shell / rocket

Research Abstract

Sloshing describes the free-surface oscillations of a liquid in a partially filled tank, which results from lateral and longitudinal displacements or angular motions of the vehicle containing the liquid. A concentric membrane tank configuration is a possible design concept for reducing the structural weight of a launch vehicle. Due to the geometrical arrangement and flexibility of the inner tank, attitude control and propulsion system stability margins may be changed in comparison with those of the conventional tandem tank configuration.
In this research, we experimentally investigated the dynamic characteristics of the lateral liquid sloshing in a concentric tank from the view-point of attitude stability and control. We conducted an experiment using a circular cylindrical tank having a rigid outer wall of 33.4-cm diameter and a flexible inner wall of 23.4-cm diameter. The three materials used for the inner walls were, rigid acrylic, Kapton film, and polyethylene foam sheeting.
We found that in the membrane wall, the outer part resonant phenomenon was difficult to clearly discern, because of the heavy motion coupling of the inner and outer liquids through the flexible membrane wall. Consequently the apparent damping ratio was increased with decreasing rigidity of the membrane wall.