Normal characteristics of a UAV air slot propeller

Lyubov Markovska

Abstract


This paper presents the results of a numerical study of the influence of passive control of the boundary layer around the propeller blade by creating cuts (slits) in the body of the propeller blade of the type 1045, which is widely used in unmanned aerial vehicles (UAVs). The relevance of the topic is due to the rapid growth of UAVs’ role in ensuring Ukraine’s defense capability, particularly in combat operations, reconnaissance and cargo delivery, rescue missions, and mine clearance. Improving the aerodynamic characteristics of such devices is an important component of their effective functioning. These requirements can be met by increasing the UAV propeller’s traction properties. The critical angle of attack can be increased if the flow disruption from the blade surface is prevented by controlling the boundary layer. This study aims to analyze the influence of different options for placing slots in the blade body on the efficiency (efficiency) of the propeller depending on the dimensionless speed coefficient (normal characteristic - Advance Ratio). Seven configurations of slots were modeled in the blade body. The thrust and torque of the modified propellers were calculated using numerical modeling by solving the Navier-Stokes equations using Florian Menter’s two-layer turbulence model (SST Transitional No. 4 Gamma Theta) in the ANSYS CFX environment, which provides high accuracy of boundary layer calculations. The dependence of the efficiency on the normal characteristic was obtained and compared with the thrust data for each modification option. Individual configurations of slots in the blade body can improve the propeller’s aerodynamic properties, particularly increasing thrust at low speeds, which is critical for UAV takeoff, landing, and maneuvering. On the contrary, other options reduce efficiency, indicating the need for further research. The results obtained can be used to optimize the design of propellers with slots to increase the overall efficiency, controllability, and stability of UAVs.

Keywords


unmanned aerial vehicle (UAV); slots; propeller; boundary layer control; efficiency; speed coefficient; thrust; efficiency coefficient

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DOI: https://doi.org/10.32620/aktt.2025.4sup1.07