Modeling of Unmanned Aerial Vehicles (UAV) propellers in a global, multidisciplinary aeroacoustic optimization was investigated. The modeling consists three aspects: geometry, aerodynamics, and aeroacoustics. Firstly, parametric geometry model established using chord, twist, sweep distributions along the radius, defined by splines to ensure smoothness. Additionally, airfoil parameters including...

Abstract In this paper, the unsteady flow around a high-speed train is numerically simulated by detached eddy simulation method (DES), and far-field noise predicted using Ffowcs Williams-Hawkings (FW-H) acoustic model. The reliability of numerical calculation verified wind tunnel experiments. superposition relationship between radiated local aerodynamic sources whole source analyzed. Since trai...

The more restrictive airspace regulations force drone manufacturers to take into account the noise emitted by during design phase, along with its aerodynamic performance increase flight time. A Non-Linear Vortex Lattice Method (NVLM), coupled Farassat Formulation-1A of Ffowcs-Williams and Hawkings acoustic analogy is used evaluate aeroacoustic MAV rotors. Pymoo, a Python-based optimization fram...

Propulsion noise is an enduring problem of significant military and environmental importance. Hence, it crucial to investigate propeller characteristics. In this study, the hydrodynamic performance level DARPA (Defense Advanced Research Projects Agency) Suboff submarine with E1619 were analyzed. The hull resistance hydrodynamics studied separately, numerical results validated using available ex...

It is noteworthy to explore potential measures for further reducing the aerodynamic drag and noise of high-speed pantographs. This paper proposes a method introducing spanwise waviness into upper lower arms. The improved delayed detached eddy simulation (IDDES) Ffowcs Williams Hawkings (FW-H) equation are used flow field sound propagation calculation, respectively. effects wavelength, wave ampl...

The pantograph is the main noise source of high-speed trains, which middle and upper parts account for about 50% whole energy. Taking CRH380BL as basic prototype, three aerodynamic reduction measures opening, slotting, airfoil are introduced to build a new pantograph, their aeroacoustic performances comprehensively investigated through large eddy simulation (LES) Ffowcs Williams–Hawkings (FW-H)...

The Ffowcs-Williams and Hawkings acoustic analogy was exploited to reconstruct the signature of a tip-loaded propeller with winglets across range working conditions, from design toward higher loads. Results Large-Eddy Simulations, conducted on computational grid consisting about 5 × 109 points, were utilized. For decreasing values advance coefficient, that is for increasing rotational speeds pr...

This paper investigates the effect of geometric parameters -- rod diameter and distance between airfoil on noise generated by rod-airfoil configuration using experimental numerical techniques. The simulations are carried out low-dissipation up-wind scheme Delayed-Detached-Eddy Simulation (DDES) approach with Shear-Layer Adapted (SLA) sub-grid length scale (SGS) for a faster transition RANS LES....

In order to understand the mechanism by which a pantograph can generate aerodynamic noise and grasp its far-field characteristics, simplified double-strip is analyzed numerically. Firstly, unsteady flow field around simulated in frame of large eddy simulation (LES) technique. Then location main source determined using surface fluctuating pressure data vortex structures are means Q-criterion. Ba...