Flow Profile Analysis of High-altitude Weather Balloons Via Transient Fluid-structure Interaction Simulation in ANSYS

Abstract:

Atmospheric Gravity Waves (AGWs) are a global mechanical process that propagate energy throughout the Earth’s atmosphere. As such, defining a better understanding of atmospheric energy propagation via AGWs allows for the refinement of existing climatological models, improving prediction of meteorological events on a local to global scale. One current method employed in AGW detection is using radiosonde measurements of ambient atmospheric conditions. During the launch process of radiosondes on weather balloons, a main goal is to achieve consistent rise rates necessary for accurate analysis of ambient conditions and atmospheric profiles which are key to AGW detection. A better understanding of the air flow profile over the balloon-radiosonde package during flight will allow us to optimize balloon rise-rates, understand local atmospheric interaction with the radiosonde, and improve total accuracy of radiosonde measurement pertinent to AGW detection. To accomplish the goal of defining the airflow profile over a balloon-radiosonde package, a fluid-structure interaction (FSI) simulation was built using ANSYS multi-physics suite. In this simulation, first order approximations of a latex analog (neoprene) deformation were derived from a fluid load analysis done in ANSYS Fluent CFD suite. Methods employed in fluid analysis include a first order approximation of transient turbulent flow. Presented will be results of the current progress on the total FSI simulation, affected flow profile due to balloon deformation in conjunction with an in-depth look of estimated flow profiles at chosen altitudes with corresponding ambient conditions (atmospheric densities, temperatures, rise rates, etc.).