Cascade nonlinear feedforward-feedback control of stagnation pressure in a supersonic blowdown wind tunnel

Measurement ◽  
2017 ◽  
Vol 95 ◽  
pp. 424-438 ◽  
Author(s):  
Biljana Ilić ◽  
Marko Miloš ◽  
Jovan Isaković
Keyword(s):  
Feedback Control ◽  
Wind Tunnel ◽  
Stagnation Pressure

scholarly journals Remote and Feedback Control of the Flap Angle in a Wind Tunnel Test Model by Optical Measurement

Aerospace ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 11
Author(s):  
Kazuhisa Chiba ◽  
Tatsuro Komatsu ◽  
Hiroyuki Kato ◽  
Kazuyuki Nakakita
Keyword(s):  
Feedback Control ◽  
Wind Tunnel ◽  
Optical Measurement ◽  
Wind Tunnel Test ◽  
Measurement Technology ◽  
Test Model ◽  
Measurement Equipment ◽  
Feedback Control System ◽  
Aerodynamic Coefficients ◽  
Japan Aerospace Exploration Agency

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.

scholarly journals Prediction of total pressure characteristics in the settling chamber of a supersonic blowdown wind tunnel

2011 ◽  
Vol 115 (1171) ◽  
pp. 557-566 ◽  
Author(s):  
G. K. Suryanarayana ◽  
S. R. Bhoi
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Storage Tank ◽  
Stagnation Pressure ◽  
Rate Of Change ◽  
Settling Chamber ◽  
Low Mach Number ◽  
High Mach ◽  
And Storage ◽  
Pressure Characteristics

Abstract Occurrence of transient starting and stopping loads during tests at high Mach numbers is one of the major problems in intermittent blowdown wind tunnels. It is believed that in order to overcome this problem, the wind tunnel could be started at a low Mach number and low stagnation pressure; the desired high Mach number condition could be reached by continuously changing the nozzle contour while synchronously increasing the stagnation pressure. After completing the tests, the nozzle could be brought back to the initial low Mach number accompanied by synchronous decrease in the stagnation pressure. In such a scenario, it is important to ensure that the pressure regulating valve (PRV) of the wind tunnel delivers and maintains a specified minimum stagnation pressure at any Mach number, so that supersonic breakdown of the test section flow does not occur. In this paper, the problem is formulated based on quasi-steady one-dimensional isentropic equations and numerically solved to predict the time histories of settling chamber pressure and storage tank pressure for a given trajectory of the opening of the PRV, as the Mach number is changed from Mach 1 to 4·0 continuously in four seconds and vice versa. The effects of rate of change of PRV open area and rate of change of Mach number on the stagnation pressure characteristics in the settling chamber and storage tank are predicted. The measured trajectories of the PRV in experiments in the NAL 0·6m transonic wind tunnel are used as input to the prediction program to validate the methodology. Predictions indicate that when the nozzle throat is changed from Mach 1 to 4 in four seconds, the settling chamber stagnation pressure rapidly builds up and approaches the pressure in the storage tank. Predictions show an alarming rise in free stream dynamic pressure during transition from Mach 1 to 4 and vice versa, which needs to be verified through measurements.

scholarly journals Energy Simulation of Marine Currents through Wind Tunnel with use the Haar Wavelet for Electromagnetic Brake Systems

2021 ◽  
Vol 15 ◽  
pp. 44-50
Author(s):  
Aldo A. Belardi ◽  
Antônio H. Piccinini
Keyword(s):  
Renewable Energy ◽  
Control System ◽  
Feedback Control ◽  
Wind Tunnel ◽  
Electrical Energy ◽  
Haar Wavelet ◽  
Energy Simulation ◽  
Feedback Control System ◽  
Electromagnetic Brake ◽  
Marine Currents

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.

scholarly journals Model-based stagnation pressure control in a supersonic wind tunnel

2016 ◽  
Vol 44 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Biljana Ilić ◽  
Marko Miloš ◽  
Mirko Milosavljević ◽  
Jovan Isaković
Keyword(s):  
Wind Tunnel ◽  
Pressure Control ◽  
Stagnation Pressure ◽  
Supersonic Wind Tunnel ◽  
Model Based

Advanced Flow Control for Supersonic Blowdown Wind Tunnel Using Extended Kalman Filter

2013 ◽  
Author(s):  
Jiaqi Xi ◽  
Qiang Zhang ◽  
Mian Li ◽  
Zhaoguang Wang
Keyword(s):  
Kalman Filter ◽  
Wind Tunnel ◽  
Flow Control ◽  
Extended Kalman Filter ◽  
Control Strategy ◽  
Test Section ◽  
Stagnation Pressure ◽  
Operating Conditions ◽  
Wind Tunnels ◽  
Wide Range

Supersonic wind tunnels provide controlled test environments for aerodynamic research on scaled models. During the experiment, the stagnation pressure in the test section is required to remain constant. Due to the nonlinearity and distributed characteristics of the controlled system, a robust controller with effective flow control algorithms is required, which is then capable of properly working under different operating conditions. In this paper, an Extended Kalman Filter (EKF) based flow control strategy is proposed and implemented in the controller. The control strategy is designed based on the state estimation of a real blowdown wind tunnel, which is carried out under an EKF structure. One of the distinctive advantages of the proposed approach is its adaptability to a wide range of operating conditions for blowdown wind tunnels. Furthermore, it provides a systematic approach to tune the controller parameters to ensure the stability of the controlled air flow. Experiments with different initial conditions and control targets have been conducted to test the applicability and performance of the designed controller. The results demonstrate that the controller and its strategies can effectively control the stagnation pressure in the test section and maintain the target pressure during the stable stage of the blowdown process.

The Ludwieg Pressure-Tube Supersonic Wind Tunnel

1963 ◽  
Vol 14 (2) ◽  
pp. 143-157 ◽  
Author(s):  
A. J. Cable ◽  
R. N. Cox
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Nozzle Exit ◽  
High Speed ◽  
Layer Growth ◽  
Stagnation Pressure ◽  
Pressure Tube ◽  
Rarefaction Waves ◽  
Supersonic Wind Tunnel ◽  
Blow Down

SummaryA description is given of a supersonic pressure-tube wind tunnel which has been constructed at A.R.D.E. This is a blow-down tunnel which uses as a reservoir a long tube filled with gas under pressure. A quasi-steady supersonic flow is achieved by expanding in a convergent-divergent nozzle the subsonic flow behind rarefaction waves which propagate down the tube when a diaphragm at the nozzle exit is burst. The theory of the operation of the tunnel is given and calculations are made of the boundary-layer growth along the tube. Pressure-time records were obtained in the tube, and a high speed camera was used to obtain pictures of the flow round a model. Measurements also included a pitot-tube traverse of the nozzle exit, and the Mach number distribution was determined from the ratio of the pitot to the stagnation pressure. Tests showed that, as predicted, a constant stagnation pressure was obtained ahead of the nozzle, and it is considered that a tunnel of this type would be a cheap and simple way of obtaining an intermittent tunnel with adequate running time for many types of test, and capable of operating at a Reynolds number of more than 107 per inch at a Mach number of about 3·5.

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