Computational Modelling of Fixed and Rotary Wing Aerodynamics Operating in Close Proximity to Wavy Free Surfaces

2014 ◽  
Author(s):  
R. Prasad ◽  
V. Dwivedi ◽  
M. Damodaran
Keyword(s):  
Computational Modelling ◽  
Free Surfaces ◽  
Close Proximity ◽  
Rotary Wing ◽  
Wing Aerodynamics

Finite Element Adaptive Multigrid Euler Solver for Rotary Wing Aerodynamics

AIAA Journal ◽  
10.2514/2.921 ◽  
2000 ◽  
Vol 38 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Carlo L. Bottasso ◽  
Mark S. Shephard
Keyword(s):  
Finite Element ◽  
Euler Solver ◽  
Rotary Wing ◽  
Wing Aerodynamics

Energy cost of Piloting fixed- and rotary-wing aircraft

1969 ◽  
Vol 26 (3) ◽  
pp. 282-285 ◽  
Author(s):  
D. E. Littell ◽  
R. J. T. Joy
Keyword(s):  
Energy Expenditure ◽  
Energy Cost ◽  
Military Medicine ◽  
Minute Volume ◽  
Ground Contact ◽  
Us Army ◽  
Energy Expenditures ◽  
Close Proximity ◽  
Helicopter Pilots ◽  
Rotary Wing

The energy cost of piloting three US Army helicopters (light, utility, and medium) and one utility fixed-wing aircraft was investigated. Energy expenditure was calculated from expired minute volume and expired air oxygen content measured during the basal state and in normal flight conditions. Data were collected on a total of 16 pilots, 5 of whom flew all three helicopters. All of the helicopter pilots were experienced test pilots. The data indicate that, for these pilots, and flying conditions studied (level flight in good weather) and aircraft, the energy cost must be classed as very light work, averaging 1.79 kcal/min. The energy cost of flying the fixed-wing aircraft by less experienced pilots was similar to previously reported energy expenditures for such aircraft. The data were segregated to separate measurements made at altitude from those made during flight in close proximity to the ground (take off, hover, etc). In three of the four aircraft, the pilot's energy expenditure was greater when ground contact was possible. flying; energy expenditure; work fatigue; helicopters; bioenergetics; oxygen consumption; military medicine Submitted on August 12, 1968

scholarly journals Investigation of Rotor–Airframe Interaction Noise Associated with Small-Scale Rotary-Wing Unmanned Aircraft Systems

2020 ◽  
Vol 65 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Nikolas S. Zawodny ◽  
Douglas D. Boyd
Keyword(s):  
Rotor Blade ◽  
Unmanned Aircraft ◽  
Tip Clearance ◽  
Unmanned Aircraft Systems ◽  
Small Scale ◽  
Acoustic Measurements ◽  
Aircraft Systems ◽  
Brushless Motor ◽  
Close Proximity ◽  
Rotary Wing

In this study, acoustic measurements of a hover condition are taken on isolated rotor–airframe configurations representative of small-scale, rotary-wing unmanned aircraft systems (UAS). Each rotor–airframe configuration consists of two fixed-pitch blades powered by a brushless motor, with a simplified airframe geometry intended to represent a generic multicopter arm. In addition to acoustic measurements, computational fluid dynamics–based aeroacoustic predictions are implemented on a subset of the experimentally tested rotor–airframe configurations in an effort to better understand the noise content of the rotor–airframe systems. Favorable agreements are obtained between acoustic measurements and predictions, based on both time- and frequency-domain postprocessing techniques. Results indicate that close proximity of airframe surfaces results in the generation of considerable tonal acoustic content in the form of harmonics of the rotor blade passage frequency (BPF). Analysis of the acoustic prediction data shows that the presence of the airframe surfaces can generate noise levels either comparable to or greater than the rotor blade surfaces under certain rotor tip clearance conditions. Analysis of the on-surface Ffowcs Williams and Hawkings source terms provides insight as to the predicted physical noise-generating mechanisms on the rotor and airframe surfaces.

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