Nonlinear dynamic simulation and stress prediction for a tethered aerostat

Aerostats are lighter-than-air vehicles tethered to the ground by a long cable. Their operational availability as a communications and surveillance platform, however, is limited by high winds during inclement weather. This paper develops aerostat dynamic models that predict the aerostat motion and tether and confluence line stresses in response to wind inputs. A nonlinear dynamic simulation is developed based on recent models for lighter-than-air vehicles that more accurately reflect aerodynamic loading in gust environments. Comparison of the dynamic response with previously published flight data for the TCOM 71M aerostat validates the model and demonstrates up to 44% higher accuracy results than previous techniques. A static truss finite element model predicts confluence line loads based on the dynamic response.