Low-Speed Aerodynamic Forces and Moments Acting on the Human Body

1975 ◽  
Author(s):  
Peter R. Payne
Keyword(s):  
Human Body ◽  
Aerodynamic Forces ◽  
Low Speed

scholarly journals Numerical Simulation for Engine/Airframe Interaction Effects of the BWB300 on Aerodynamic Performances

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Yu ◽  
Dong Li ◽  
Yue Shu ◽  
Zeyu Zhang
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Separated Flow ◽  
Simulation Method ◽  
Interaction Effects ◽  
Surface Flow ◽  
Concept Design ◽  
Aerodynamic Forces ◽  
Low Speed ◽  
Aerodynamic Performances

The engine/airframe interaction effects of the BWB300 on aerodynamic performances were analyzed by using the numerical simulation method. The BWB300 is a 300-seat Blended Wing Body airplane designed by the Airplane Concept Design Institute of Northwestern Polytechnical University. The engine model used for simulation was simplified as a powered nacelle. The results indicated the following: at high speed, although the engine/airframe interaction effects on the aerodynamic forces were not significant, the airframe’s upper surface flow was greatly changed; at low speed, the airframe’s aerodynamic forces (of the airplane with/without the engine) were greatly different, especially at high attack angles, i.e., the effect of the engine suction caused the engine configuration aerodynamic forces of the airframe to be bigger than those without the engine; and the engine’s installation resulting in the different development of flow separation at the airframe’s upper surface caused greater obvious differences between the 2 configurations at high angles and low speed. Moreover, at low-speed high attack angles, the separated flow from the blended area caused serious distortion at the fan inlet of the engine.

Ground manoeuvres of aircrafts in narrow spaces by all-wheel-steering

2021 ◽  
pp. 095440622110095
Author(s):  
Francesco Sorge
Keyword(s):  
Aerodynamic Forces ◽  
Low Speed ◽  
Critical Speeds ◽  
Flight Decks ◽  
All Wheel Steering ◽  
Point Trajectories

The present analysis deals with the ground taxiing of aircrafts and considers, in particular, their turning at rather low speed with very small path radii among obstacles that may be very close to each other, for example inside the hangars or on the flight decks of the aircraft carriers where other planes stand stationary. To succeed in this operation, it is crucial to optimize the path and avoid dangerous collisions or, more generally, the interference in the ground projection between the obstacles and the band enclosing all the point trajectories of the plane. The essential innovation here proposed for this purpose consists in making all the wheels of the undercarriage steerable, assuming electrically motorized struts, and in searching for the best correlation among the steering angles in order to optimize the path. The geometrical and dynamical nonlinearities due to the relatively large steering angles, to the changes of the cornering stiffness with the vertical loads on the wheels and to the inertial and the aerodynamic forces will be included in the analysis. The rollover critical speeds will be calculated on varying the path radius.

Modeling of Decelerated Descent of an Elongated Body With Vectored Thrust

2018 ◽  
Author(s):  
Konstantin I. Matveev ◽  
John P. Swensen ◽  
Matthew E. Taylor
Keyword(s):  
Target Location ◽  
Thrust Force ◽  
Cylindrical Body ◽  
The Body ◽  
Dynamics Model ◽  
Aerodynamic Forces ◽  
Low Speed ◽  
Stable Orientation ◽  
The Subject ◽  
Vectored Thrust

The subject of this study is a simplified model of an elongated body intended for controlled, low-speed landing after being released far above the ground. The envisioned system is structurally simple and compact. It comprises a cylindrical body with a vectored propulsor attached to its upper end. Far from the ground a low-magnitude thrust force directs the body toward the target site and maintains stable orientation, whereas near the ground higher thrust decelerates and directs the body to ensure low-speed landing near the target location. A 6-DOF dynamics model is applied for simulating the body descent. A strip approach is used for evaluating aerodynamic forces on the body. The thrust magnitude and direction are the controlled parameters. Results of simulations are presented for several scenarios of the body descending on the ground in calm air and in the presence of wind.

scholarly journals Simulation of a Dummy Crash Test in ADAMS

2022 ◽  
Vol 24 (1) ◽  
pp. B20-B28
Author(s):  
Marek Jaśkiewicz ◽  
Damian Frej ◽  
Miloš Poliak
Keyword(s):  
Design Process ◽  
Human Body ◽  
The Body ◽  
Simulation Program ◽  
Crash Test ◽  
Low Speed ◽  
Simulated Model ◽  
Stiffness And Damping ◽  
Crash Tests

The article presents a model designed dummy for crash test in ADAMS. The simulated model dummy has dimensions, shapes and mass corresponding to a 50-percentile man. The simulation program allows modification of the dummy parameters. It allows to study the dynamics of motion, distribution of forces and loads of individual parts of the body of the simulated model. The article describes the design process and how to select the appropriate stiffness and damping joints for the simulated dummy. The article contains the results of simulation crash tests performed in the ADAMS program, which were compared to results of the Hybryd III dummy physical crash test. The simulation is designed to reflect the greatest compliance of the movements of individual parts of the human body during the low speed collision.

scholarly journals A Study of Multi-Objective Aerodynamic Optimization Design for Variable Camber Airfoils and High Lift Devices

2018 ◽  
Vol 36 (1) ◽  
pp. 83-90
Author(s):  
Wangyi Zhou ◽  
Junqiang Bai ◽  
Lei Qiao ◽  
Yasong Qiu ◽  
Rui Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Deflection Angle ◽  
Aerodynamic Optimization ◽  
Aerodynamic Forces ◽  
High Lift ◽  
Low Speed ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Design Variables

Aiming at the synthetical optimization of the aerodynamic performance between the low-speed condition of two-dimensional high lift devices during take-off and landing phase and the high-speed condition of variable camber airfoil during cruise phase, an aerodynamic optimization design method for high lift device based on Kriging based surrogate model and multi-objective genetic algorithm has been developed. With the application of Adaptive Dropped Hinge Flap mechanism, the low-speed take-off and landing performance and high-speed cruise performance of the aircraft is improved by coupling deflection of the flap and spoiler. The position of flap hinge, deflection angle of spoiler and deflection angle of flap are taken as design variables; The Navier-Stokes equations are used to predict the aerodynamic forces of initial samples; The Kriging based surrogate model is employed to establish the algebraic relation between design variables and aerodynamic forces at take off, landing and cruise, obtaining four efficient prediction models for aerodynamic forces; Multi-objective optimization design with multi-objective genetic algorithm is conducted on the basis of surrogate models. The automatic generation of computational grid is achieved by the mesh deformation method based on RBF (Radial Basis Function) when the design variables change. On the basis of efficient global multi-objective optimization design platform, the synthetical optimization of high-speed and low-speed aerodynamic performance is conducted; The multi-objective solution set of the Pareto frontier is verified and analyzed, and the optimal solution with well matched high and low speed performance is selected.

Pathogenesis of Vocal Cord Polyps

1982 ◽  
Vol 91 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Oskar Kleinsasser
Keyword(s):  
Blood Vessels ◽  
Vocal Cord ◽  
Human Body ◽  
Separate Entity ◽  
Aerodynamic Forces ◽  
Electron Microscopic ◽  
Vocal Cords ◽  
Edema Fluid ◽  
Microscopic Investigations ◽  
Reactive Processes

Polyps of the vocal cords are a separate entity occurring nowhere else in the larynx or in the human body. Gelatinous and telangiectatic, but mainly transitional types of polyps can be discriminated. Histological, histochemical and electron microscopic investigations on a series of polyps show that an alteration of the permeability of blood vessels may be of importance, allowing the extravasation of edema fluid, fibrin or erythrocytes. Following this, reactive processes develop with the formation of labyrinthine vascular spaces. This process is very similar to the organization of a thrombus. Since polyps occur mainly in people who use their voices very intensively, and develop at the site of maximum muscular and aerodynamic forces exerted during phonation, vocal cord polyps are considered a sequela of a phonotrauma.

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