CBL - Campus del Baix Llobregat

Projecte llegit

Títol: Assessment of aerodynamic drag on a HAPS payload

Estudiants que han llegit aquest projecte:

Director/a: ARIAS CALDERÓN, SANTIAGO

Departament: FIS

Títol: Assessment of aerodynamic drag on a HAPS payload

Data inici oferta: 03-02-2025     Data finalització oferta: 03-10-2025


Estudis d'assignació del projecte:
    GR ENG SIST AEROESP
Tipus: Individual
 
Lloc de realització: EETAC
 
Paraules clau:
HAPS, payload, drag, OpenFOAM
 
Descripció del contingut i pla d'activitats:
High Altitude Platform Stations (HAPS) represent an emerging technology that operates in the stratosphere, providing the possibility to fill the gap in the current communication and Earth observation ecosystems. These platforms are designed to operate at high altitudes for long periods, offering an alternative to traditional satellites and Unmanned Aerial vehicles (UAV). HAPS can support a wide range of applications, and each payload is designed for a specific purpose.

The objective of this project is to compute the aerodynamic drag of a HAPS payload. To accomplish this, the software used will be OpenFOAM, which is an open-source Computational Fluid Dynamics (CFD), in combination with Paraview for results analysis and visualization.

This project will include preprocessing and postprocessing phases. During the preprocessing stage, different mesh setups will be created, considering various mesh configurations to analyse accuracy and resolution. This phase will also include establishing the simulation parameters. In the postprocessing phase, the data acquired from the simulations will be examined with Paraview. This phase will enable the visualization and interpretation of the data, especially focusing on the aerodynamic drag.
 
Overview (resum en anglès):
High Altitude Platform Stations (HAPS) are unmanned aerial platforms that operate in the stratosphere. These platforms offer the flexibility to perform a wide range of use cases depending on the type of payload they carry, with Earth observation and telecommunications being the two main applications. HAPS are considered an emerging technology that is just entering in the commercial phase. For this reason, the published information about the aerodynamic behaviour of these payloads is very limited. The objective of this project is to analyse the drag generated by a specific payload and compare it with the aerodynamic requirement imposed by the platform. The payload under study is part of the Strat-Observer program from Airbus Defense and Space.
In this project, Computational Fluid Dynamics (CFD) has been used. Specifically, the simulations were carried out with Open Field Operation and Manipulation (OpenFOAM) and in two-dimensions, using a steady-state solver (simpleFoam) and a transient solver (pisoFoam). The methodology followed was divided into three stages: pre-processing, simulation and post-processing, using specific tools in each one.
Moreover, to validate the simulation configuration, a validation process was performed, including: a mesh convergence study, an analysis of the domain size, a comparison between turbulence models (k-epsilon and k-omega SST), a variation of the relaxation factors, an analysis of the incorporation of the extension tube between the platform and the payload and a study of the time step for the transient simulations.
Once the configuration was validated, the final simulations were performed. Firstly, a variation of the angle of attack was analysed with both the steady-state and transient solver. Secondly, the effect on the drag coefficient of incrementing the Reynolds number was also studied. Finally, a comparison was made between the results and the drag coefficient of other reference geometries as well as between the results and the imposed drag requirement. The obtained results of this geometry serve as a point of reference to orientate future design decisions, help to prevent errors and reduce economic costs.

© CBLTIC Campus del Baix Llobregat - UPC