Practical Methodology for the Inclusion of Nonlinear Slosh Damping in the Stability Analysis of Liquid-Propelled Space Vehicles

Ottander, John A ; Hall, Robert A ; Powers, J F

关键词: CONTROL STABILITY;    SPACE LAUNCH SYSTEM (SLS);    ATTITUDE CONTROL;    NONLINEARITY;    LIQUID SLOSHING;    SPACECRAFT LAUNCHING;    DAMPING;    STABILITY TESTS;    FUNCTIONAL ANALYSIS;    BAFFLES;    TIME DOMAIN ANALYSIS;    PROPORTIONAL CONTROL;    STABILITY;   

RP-ID  :  M17-6074

学科分类：航空航天科学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

A method is presented that allows for the prediction of the magnitude of limit cycles due to adverse control-slosh interaction in liquid propelled space vehicles using non-linear slosh damping. Such a method is an alternative to the industry practice of assuming linear damping and relying on: mechanical slosh baffles to achieve desired stability margins; accepting minimal slosh stability margins; or time domain non-linear analysis to accept time periods of poor stability. Sinusoidal input describing functional analysis is used to develop a relationship between the non-linear slosh damping and an equivalent linear damping at a given slosh amplitude. In addition, a more accurate analytical prediction of the danger zone for slosh mass locations in a vehicle under proportional and derivative attitude control is presented. This method is used in the control-slosh stability analysis of the NASA Space Launch System.