Performance Model for Reversible Fluid Balloons

The Altitude Control Experiment (ALICE) is a balloon system that consists of a helium lifting balloon and a buoyancy-controlling freon R114 balloon. Condensation of freon gas in the cooler upper atmosphere and vaporization of liquid freon in the warmer lower atmosphere can be effectively used to adjust the net buoyant force so that the balloon system may float between desirable ranges of altitudes.This report summarizes efforts to produce an analytical model to predict the performance of this type of altitude control balloon in the earth's atmosphere. Various interactive parameters that are influential to the dynamics of the system were identified and treated. The analytical model developed herein correlated well with three ALICE day flight trajectories and one ALICE night flight trajectory in the earth's atmosphere. A similar approach can be applied to the design of a Venusian balloon system that could repeatedly travel to the lower, hot altitudes or surface of Venus for imaging or science experiments and then float higher in order to cool the electronics.