Aerodynamic Interference in Confined Environments with Tilted Propellers: Wall Effect and Corner Effect

2021 ◽  
Author(s):  
A. Garofano-Soldado ◽  
G. Heredia ◽  
A. Ollero
Keyword(s):  
Wall Effect ◽  
Corner Effect ◽  
Aerodynamic Interference

Aerodynamic interference test of quad tilt rotor aircraft in wind tunnel

2019 ◽  
Vol 233 (15) ◽  
pp. 5553-5566 ◽  
Author(s):  
Kun Chen ◽  
Zhiwei Shi ◽  
Shengxiang Tong ◽  
Yizhang Dong ◽  
Jie Chen
Keyword(s):  
Wind Tunnel ◽  
Reference Value ◽  
Ground Effect ◽  
Open Loop ◽  
Force Balance ◽  
Scale Model ◽  
Operating Condition ◽  
Tilt Rotor ◽  
Interference Test ◽  
Aerodynamic Interference

There is an obvious aerodynamic interference problem that occurs for a quad tilt rotor in near-ground hovering or in the conversion operating condition. This paper presents an aerodynamic interference test of the quad tilt rotor in a wind tunnel. A 1:35 scale model of the quad tilt rotor is used in this test. To substitute for the ground, a moveable platform is designed in a low-speed open-loop wind tunnel to simulate different flight altitudes of the quad tilt rotor in hovering or forward flight. A rod six-component force balance is used to measure the loads on the aircraft, and the flow field below the airframe is captured using particle image velocimetry. The experimental results show that the ground effect is significant when the hover height above the ground is less than the rotor diameter of the quad tilt rotor aircraft, and the maximum upload of the airframe is approximately 12% of the total vertical thrust with the appearance of obvious fountain flow. During the conversion operating condition, the upload of the airframe is reduced compared with that in the hovering state, which is affected by rotor wake and incoming flow. The aerodynamic interference test results of the quad tilt rotor aircraft have important reference value in power system selection, control system design, and carrying capacity improvement with the advantage of ground effect.

scholarly journals Aerodynamic Interference Caused by the Inboard Leading-Edge Flap on the Outboard Area of the Cranked Arrow Wing

2015 ◽  
Vol 99 ◽  
pp. 1642-1646 ◽  
Author(s):  
Kosuke Toyoda ◽  
Dongyoun Kwak ◽  
Masayoshi Noguchi ◽  
Kenichi Rinoie
Keyword(s):  
Leading Edge ◽  
Aerodynamic Interference

Apparent Contraction of Edge Angles

Perception ◽  
1998 ◽  
Vol 27 (10) ◽  
pp. 1209-1219 ◽  
Author(s):  
Akiyoshi Kitaoka
Keyword(s):  
Three Dimensional ◽  
Corner Effect ◽  
Edge Contrast

The corner effect, the Münsterberg illusion, and the Cafe Wall illusion are explained by a model postulating that the corner effect is an orientation illusion specific to corner edges and that the perceived orientations of these edges are shifted toward angle contraction. It is also assumed that the effect is greatest when the corner edges show the same or similar edge contrast at the corner. This model yields three new types of illusions: the ‘checkered illusion’, the ‘illusion of shifted gradations’, and the ‘illusion of striped cords’. Each of them gives many variations making a three-dimensional impression.

Side-Wall Effect on the Long-Wave Instability in Kolmogorov Flow

1998 ◽  
Vol 67 (5) ◽  
pp. 1597-1602 ◽  
Author(s):  
Hiroaki Fukuta ◽  
Youichi Murakami
Keyword(s):  
Side Wall ◽  
Wall Effect ◽  
Wave Instability ◽  
Kolmogorov Flow ◽  
Long Wave

scholarly journals Cable Suspension and Balance System with Low Support Interference and Vibration for Effective Wind Tunnel Tests

2021 ◽  
Author(s):  
Keum-Yong Park ◽  
Yeol-Hun Sung ◽  
Jae-Hung Han
Keyword(s):  
Wind Tunnel ◽  
Vibration Suppression ◽  
Aerodynamic Load ◽  
Test Model ◽  
Wind Tunnel Tests ◽  
Balance System ◽  
Motion Responses ◽  
Vibration Responses ◽  
Aerodynamic Interference ◽  
Support Interference

AbstractA cable-driven model support concept is suggested and implemented in this paper. In this case, it is a cable suspension and balance system (CSBS), which has the advantages of low support interference and reduced vibration responses for effective wind tunnel tests. This system is designed for both model motion control and aerodynamic load measurements. In the CSBS, the required position or the attitude of the test model is realized by eight motors, which adjust the length, velocity, and acceleration of the corresponding cables. Aerodynamic load measurements are accomplished by a cable balance consisting of eight load cells connected to the assigned cables. The motion responses and load measurement outputs were in good agreement with the reference data. The effectiveness of the CSBS against aerodynamic interference and vibration is experimentally demonstrated through comparative tests with a rear sting and a crescent sting support (CSS). The advantages of the CSBS are examined through several wind tunnel tests of a NACA0015 airfoil model. The cable support of the CSBS clearly showed less aerodynamic interference than the rear sting with a CSS, judging from the drag coefficient profile. Additionally, the CSBS showed excellent vibration suppression characteristics at all angles of attack.

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