Simulation Example - Blimp Buoyancy

Overview

Blimps are magnificent lighter-than-air airships. While they were originally deployed for aerial surveillance and payload transport, today they are mostly used for advertisement and to hold video cameras during major sporting events. Blimps fly using the same principle as helium balloons. They contain lighter-than-air gas (generally helium), so that the overall weight of the blimp is lower than the buoyant force generated by the surrounding air. The positive buoyancy keeps a blimp in the air.

Objectives

The primary objective is to verify Archimedes' Principle by analyzing the buoyant force acting on the blimp. The pressure force acting on the blimp and the weight of the fluid displaced by the blimp must be equal for the blimp to stay neutrally aloft (maintain its altitude). To simplify the results analysis, we will focus on a toy blimp entirely filled with helium.

Setup

Download the Mesh file required for setting up the simulation and associated Case and Data files here. Follow the instructions below to set up this simulation in Ansys Fluent starting with the Mesh file. In case you face any issues setting up or running the simulation, refer to the corresponding initial and final Case and Data files.

Results and Discussion

Let’s now analyze the simulation and understand the physics of the buoyant force acting on the blimp.