Aerodynamic estimation and trim analysis for a tethered balloon

The aerodynamic characteristics of a tethered balloon with inverted Y fins were estimated by the traditional aerodynamic estimation from the flight dynamics analysis viewpoint. Taking the whole cablebody system into account, the nonlinear force trims equations and nonlinear moment trim equations were established and calculated. For different wind speed, the equilibrium points could be got from the trim equations by Newton iteration method. Comparing the trim states of different wind speed and different junction point of cable, the better junction point of the rope could be confirmed.