Aeroacoustic Noise Damping Blade Geometry with Biomimetic Texture for Leading and Trailing Edges of Unmanned Aerial Vehicles

Abstract

This invention is a multi-biomimetic microhelicopter blade geometry developed to reduce aeroacoustic noise generated by the blades in microhelicopter systems and tactical / military reconnaissance and surveillance UAVs, thereby providing acoustic invisibility / stealth and improving aerodynamic performance at low Reynolds numbers. It features sinusoidal, wavy structures (tubercles) inspired by humpback whale (Megaptera novaeangliae) fins on the leading edge and micro-serrations inspired by owl (Strigiformes) feathers on the trailing edge. The blade geometry is designed to be compatible with microhelicopter rotor root joint structures and swashplate mechanism control angles. The wavy structure on the leading edge shifts flow separation at low Reynolds numbers, increasing aerodynamic hold, while the micro-serrations on the trailing edge dampen noise caused by trailing edge turbulence.This geometry, integrated into the micro-helicopter rotor system, achieves net sound pressure level (SPL) attenuation and reduced acoustic detectability in operational missions without compromising aerodynamic thrust efficiency.

Description

utfcode utf8.sty 3.10 UTF-8 input encoding 13.06.2000 scanner for code UTF-8 installed. 1 DEFINITION SET Biomimetic Noise Damping Rotor Blades for Tactical and Micro UAVs / Helicopters Design Inventor / Applicant: Necati Semih Anıl 2 TARIFF Subject of the Invention This invention is for tactical and micro-class rotary-wing unmanned aerial vehicles (UAVs) and helicopters. Biomimetics that reduce aerodynamic noise and increase lift / drag (L / D) efficiency. It relates to a rotor blade design. Technical Problem (Previous Technique) Traditional rotor blade systems exhibit blade tip vortices and trailing edge turbulence at high rotational speeds. This creates a significant aeroacoustic noise. This situation is problematic in military and tactical operations. It increases detectability and fails to meet acoustic privacy requirements. Furthermore... Lift force in microrotors operating at low Reynolds numbers due to flow separation Losses are being incurred. Solution and Explanation of the Invention This invention solves these technical problems through the hybrid integration of two basic biomimetic structures. solves: 1. Leading Edge Tubercles: On the pectoral fins of humpback whales (Megaptera novaeangliae). The inspired sinusoidal waveform structures create indentations and protrusions at the leading edge. It ensures that the airflow adheres to the wing surface and delays the stall angle. 2. Trailing Edge Serrations: A sawtooth form inspired by owl feather geometry. The structures there break the turbulent vortex structure formed at the escape edge, thus eliminating the noise source. It is dampening. This design provides a net 4.5 dB reduction in aeroacoustic noise level on the blade. obtained and aeroacoustic performance has been optimized. Explaining the Figures • Figure 1: 3D CAD view of the biomimetic rotor blade (Leading edge tubercles and (trailing edge serrations). • Figure 2: MATLAB aeroacoustic analysis results and frequency-dB attenuation graph. 3

Claims

REQUESTS 1. It is a rotor blade structure for use in tactical and micro rotary-wing aircraft. Its feature is a tubercle geometry at the leading edge to reduce aeroacoustic noise. and the fact that it incorporates serration (toothed) geometry at the trailing edge.

2. A rotor blade structure conforming to Claim 1, characterized by the following features: the serrations at the trailing edge. It has a geometric profile angle that provides 4.5 dB of aeroacoustic sound damping.

3. A rotor blade structure conforming to Claim 1, characterized by its tubercles located at the leading edge. It is structured in a sinusoidal wave pattern.

4. A rotor blade structure conforming to Claim 1, characterized by its ability to operate at low Reynolds numbers (100). It is sized to be suitable for use in sub-gram micro-helicopter rotor systems. 4