Development of a Morphing Wing-Based Small Unmanned Aerial Vehicle

Pedestal fans are a common type of axial-flow fan used worldwide for thermal comfort. Their rotating aerodynamic blades generate a pressure difference that produces an air jet, which enhances cooling by increasing convective heat transfer from the human body. Unlike ceiling fan or wind turbine blades, axial-flow fan blades, particularly those used in pedestal fans, feature complex geometries, including blade twist, radially varying chord lengths, and specific aerofoil profiles. These geometric characteristics directly influence aerodynamic performance.

Blade design significantly affects overall fan efficiency, as airflow behaviour depends on parameters such as airfoil shape, blade setting angle, curvature, and twist distribution. The influence of blade setting angle has been extensively examined by Sheam-Chyun Lin et al.. These design features control the aerodynamic behaviour of the blade and ultimately determine the nature and strength of the resulting airflow jet. For pedestal fans, the goal is to generate a jet capable of delivering adequate thermal comfort, which is primarily governed by the velocity distribution along the jet axis. In contrast, propellers prioritize high mass flow rate generation for thrust.

Designing such blades requires careful consideration of aerodynamic performance while understanding the impact of each geometric parameter. However, due to the absence of straightforward analytical tools, evaluating performance can be challenging. Experimental testing, although accurate, is time-consuming and impractical for assessing numerous conceptual designs. Therefore, a reliable computational approach is essential for evaluating axial-flow fan blade performance efficiently.

This project follows a CFD-based methodology for assessing the aerodynamic performance of pedestal fan blades, with the long-term objective of extending the framework to other axial-flow fan designs.