Spectral feedback control of turbulent spectra in a wind tunnel

2020 ◽  
Vol 61 (8) ◽  
Author(s):  
Xiaowei He ◽  
David R. Williams
Aerospace ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 11
Author(s):  
Kazuhisa Chiba ◽  
Tatsuro Komatsu ◽  
Hiroyuki Kato ◽  
Kazuyuki Nakakita

We have developed a remote and precise feedback control system using optical measurement technology to alter the angle of a flap, which is part of a wind tunnel test model, automatically and to earn the aerodynamic data efficiently. To rectify the wasteful circumstance that Japan Aerospace Exploration Agency (JAXA)’s low-turbulence wind tunnel stops ventilation every time to switch model configurations, we repaired hardware for remote operation and generated software for feedback control. As a result, we have accomplished a system that dramatically advances the efficiency of wind tunnel tests. Moreover, the system was able to consider the deformation of the model through optical measurement; the system controlled flap angles with errors less than the minimum resolution of optical measurement equipment. Consequently, we successfully grasped the nonlinearity of three aerodynamic coefficients C L , C D , and C M p that was impossible so far.


2021 ◽  
Vol 15 ◽  
pp. 44-50
Author(s):  
Aldo A. Belardi ◽  
Antônio H. Piccinini

A demand clean and renewable energy through the use of submerged turbines. Using this new source of energy we can grow the production of electrical energy in a sustainable way. This paper presents the simulation of maritime currents using a wind tunnel which allows the comparison of speed variations of water compared to air. It also features a brake system that uses a magnetic sensor in real time using the wavelets. As an example, it can be the ones mentioned concerning the feedback control system applied in a brand WEG motor of 100 hp with 2 poles 3500rpm rotation. Using software tools, the Acquired data are post-processed.


Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 217
Author(s):  
Ken Wakimoto ◽  
Kazuhisa Chiba ◽  
Hiroyuki Kato ◽  
Kazuyuki Nakakita

This study conducted wind tunnel tests with consecutive deflection angle changes on a three-dimensional (3D) wing with a control surface to procure aerodynamic data by sweeping the deflection angle. Configuration changes of a wind tunnel test model, such as changing the deflection angle of control surfaces, are usually performed manually with the ventilation suspended. Hence, the number of configurations that can be implemented within a confined test period is restricted; the aerodynamic data gained are discrete values. To accomplish continuous angular modulation would dramatically improve the ability by sweeping through the aerodynamic data in wind tunnel tests, enhancing the test system as a tool for discussing complex physical phenomena. Thus, this study created a compact remote feedback control system using optical measurement to continuously obtain high-precision aerodynamic data without stopping the wind tunnel, eliminating human operation. In particular, this study targets a 3D wing wind tunnel model with a control surface, which is more challenging to fabricate, miniaturizing the system in a model. The system consequently attained consecutive aerodynamic data multiple times under numerous configurations, which had been impracticable to reach in the past, within a wind tunnel test period of several days, thereby dramatically increasing the testing capability. The reproducibility was quantitatively verified by comparing the multiple data for the identical configurations. Furthermore, the reliability was demonstrated using discrete data obtained by conventional stepwise deflection angle adjustments. Eventually, the system was able to grasp physical phenomena involving hysteresis.


Author(s):  
Xiaowei He ◽  
Katherine J. Asztalos ◽  
David R. Williams ◽  
Kevin Buchert
Keyword(s):  

2013 ◽  
Vol 117 (1197) ◽  
pp. 1103-1118 ◽  
Author(s):  
T. Kuk ◽  
K. Ro

Abstract A scale model of aerial refuelling drogue is built and tested to investigate active drogue stabilisation and control concepts. A set of aerodynamic control surfaces is implemented to a conventional, aerodynamically stabilised refuelling drogue. The control surfaces are designed to reduce the response of the drogue motion to atmospheric disturbance and tanker motion. This paper presents the details of design concept and experimental results based on wind-tunnel testing of a ⅓ scale model fabricated for this study. To investigate the proposed active control concept, a dynamic test rig is built for wind-tunnel experiment. The rig basically represents a hose-drogue system in terms of a 4 degree-of-freedom (DoF), single link pendulum model. System identification technique is used to obtain a drogue dynamic model, based on which a feedback control law is developed. Closed-loop dynamic testing is carried out to evaluate the effectiveness of the aerodynamic surface control module and feedback control law.


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