Related Experiment Video
Updated: May 9, 2026
08:59
Modeling and Experimental Analysis of the Single-Shaft Coaxial Motor-Pump Assembly in Electrohydrostatic Actuators
Published on: June 13, 2022
Performance and noise emission analysis of coaxial co-rotating propellersa)
Andrea Beni1, Andrea P C Bresciani1, Julien Christophe1
1von Karman Institute for Fluid Dynamics, 1640 Rhode-St-Genese, Belgium.
The Journal of the Acoustical Society of America
|May 8, 2026
Summary
Researchers studied drone propeller efficiency and noise for urban air mobility. They found a trade-off between performance and noise, with phase offset affecting tonal noise, offering insights for quieter drone design.
Area of Science:
- Aerospace Engineering
- Acoustics
- Fluid Dynamics
Background:
- Urban Air Mobility (UAM) faces challenges balancing performance and noise emissions.
- Coaxial, co-rotating propellers are key components for drone-sized aircraft.
Purpose of the Study:
- To investigate the relationship between propulsive efficiency and noise emissions in drone-sized coaxial rotors.
- To analyze the impact of phase offset and axial separation on rotor performance and acoustics.
Main Methods:
- Experimental testing of coaxial rotors in hover.
- Analytical modeling using Goldstein's formulation for rotating dipole sources.
- Numerical simulation combining panel methods and acoustic source models.
Main Results:
- An inverse relationship was observed between power loading and broadband noise.
- Tonal noise emissions were modulated by the phase offset between rotors.
- The proposed analytical and numerical methods showed consistency with experimental trends for tonal noise prediction.
Conclusions:
- Phase offset is a critical parameter for managing tonal noise in coaxial rotor systems.
- The developed fast-turnaround prediction method shows potential for early-stage multidisciplinary design of UAM vehicles.
- Optimizing propeller design requires careful consideration of the performance-noise trade-off.
Related Concept Videos
01:19Turnover Number and Catalytic Efficiency
The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from 1 to 1000 molecules per second. Catalase has the known highest turnover number, capable of converting up to 2.8×106 molecules of hydrogen peroxide into water and oxygen per second. Lysozyme has the lowest known turnover number of half a molecule per second.
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion. The...
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion. The...
01:14Node Analysis for AC Circuits
Consider an angioplasty system featuring a catheter equipped with a turbine, a critical tool for removing plaque deposits from coronary arteries. This intricate medical device operates using a circuit model reminiscent of a dual-node RLC circuit powered by a current-controlled voltage source.
To unravel the complexities of this system, nodal analysis is employed, a powerful technique founded on Kirchhoff's current law (KCL), which remains valid for phasors. AC circuits can effectively be...
To unravel the complexities of this system, nodal analysis is employed, a powerful technique founded on Kirchhoff's current law (KCL), which remains valid for phasors. AC circuits can effectively be...
01:31Energy Stored In A Coaxial Cable
A coaxial cable consists of a central copper conductor used for transmitting signals, followed by an insulator shield, a metallic braided mesh that prevents signal interference, and a plastic layer that encases the entire assembly.
In the simplest form, a coaxial cable can be represented by two long hollow concentric cylinders in which the current flows in opposite directions. The magnetic field inside and outside the coaxial cable is determined by using Ampère's law. The magnetic field inside...
In the simplest form, a coaxial cable can be represented by two long hollow concentric cylinders in which the current flows in opposite directions. The magnetic field inside and outside the coaxial cable is determined by using Ampère's law. The magnetic field inside...
01:24Wind Turbine Machine Models
In the growing field of wind energy, incorporating wind turbine models into transient stability analysis is essential. Induction and synchronous machines are the primary models used, with induction machines being prevalent due to their simplicity and reliability.
Induction machines interact through the rotating magnetic field generated by the stator and the rotor. The key parameter is slip, which is the difference between synchronous speed and rotor speed relative to synchronous speed. Slip is...
Induction machines interact through the rotating magnetic field generated by the stator and the rotor. The key parameter is slip, which is the difference between synchronous speed and rotor speed relative to synchronous speed. Slip is...
01:15Design of Transmission Shafts - Stress Analysis
Designing a transmission shaft requires a thorough understanding of the stresses induced by bending moments and torques, especially in systems where power is transferred through gears. These forces create force-couple systems at the centers of the shaft's cross-sections, leading to both transverse and torsional loading. Although shearing stresses from transverse loads are typically smaller than those from torques and are often overlooked, the significant normal stresses from these loads...
01:15Thin-Walled Hollow Shafts
In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution of...