Condition of Applying the Fourth Order of Characteristic Equation to the Dynamic Stability of Wing-In-Ground Effect Vehicles
ZHANG Hong ling 1, HUANG Guo liang 1, ZHOU Wei lin 2 1. School of Naval Architecture & Ocean Eng., Shanghai Jiaotong Univ., Shanghai 200030, China; 2. Marine Design & Research Inst. of China, Shanghai 200021
Based on discussion of the characteristics of each mode in the fifth order equation, by the relation between the roots and coefficients of the polynomials, this paper demonstrated that the dynamic stability deduced from the fourth order equation can not ensure that of the fifth order equation. By comparing the fourth order and the fifth order characteristic polynomials, the measure that the fourth equation is the valid approximation of the fifth order equation was given, from which the curves of valid approximation was drawn and the height scope of valid application of the fourth order equation was got. The influence of major aerodynamic derivatives on dynamic stability was discussed.
【CateGory Index】： U661.3