Aerodynamic Interference Between Stores

1992 ◽  
Author(s):  
F. C. Dougherty
Keyword(s):  
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

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.

scholarly journals Wind tunnel tests of aerodynamic interference of the high-rise building and its nearest city surroundings

2013 ◽  
Vol 12 (2) ◽  
pp. 079-086
Author(s):  
Grzegorz Bosak
Keyword(s):  
Wind Tunnel ◽  
Building Design ◽  
Wind Pressure ◽  
Horizontal Wind ◽  
Wind Tunnel Tests ◽  
Wind Action ◽  
Building Model ◽  
High Rise ◽  
High Rise Building ◽  
Aerodynamic Interference

The paper summarizes the results of wind tunnel tests of the influence of aerodynamic interference on wind action of a high-rise building design in Warsaw. Measurements were accomplished in Wind Engineering Laboratory of Cracow University of Technology. Wind pressures on external surfaces of the building model were acquired in two different situations. Firstly, only the building model was placed in the tunnel working section, secondly, the building model with the nearest surroundings was taken under consideration. A study of the character of wind action differences caused by the nearest surroundings of the building was the main aim of the paper. Wind pressure coefficients on the external building surfaces and the difference of horizontal wind action on full scale were compared.

Aerodynamic Interference of Cascade Blades in Synchronized Oscillation

1955 ◽  
Vol 22 (4) ◽  
pp. 503-508
Author(s):  
Chieh-Chien Chang ◽  
Wen-Hwa Chu
Keyword(s):  
Hypergeometric Functions ◽  
Aerodynamic Load ◽  
Characteristic Parameters ◽  
Harmonic Oscillations ◽  
Wake Interference ◽  
Reduced Frequency ◽  
Inaccurate Estimation ◽  
Aerodynamic Interference ◽  
Two Parameters ◽  
Single Oscillation

Abstract The failure of a compressor is sometimes due to flutter of the blades. Essentially, this problem is equivalent to a cascade in oscillation. The present analysis is to find the aerodynamic load on cascade in synchronized harmonic oscillations, pitching, and flapping. Conformal mapping is used. Two characteristic parameters are involved in the force and moment. One is μ which is related to the gap-chord ratio. The other is k which is known as reduced frequency. The main results are expressed in terms of these two parameters. Most can be reduced to closed form. The rest are given in graphs. The wake interference involves one new function C(μ,k) which is related to a ratio of two hypergeometric functions and which reduces to Theodorsen’s function C(k) in the limit of infinite gap. In a certain range of frequency and gap-chord ratio, the analysis shows quantitatively that single-oscillation airfoil theory may lead to inaccurate estimation of interference effect between blades.

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