scholarly journals Aerodynamic Force Extraction from Shock Tunnel Measurements Using the Oscillation Identification Technique

2007 ◽  
Vol 50 (169) ◽  
pp. 169-174
Author(s):  
Minoru WATARI
Keyword(s):  
Aerodynamic Force ◽  
Shock Tunnel ◽  
Identification Technique

Aerodynamic Drag Measurement in a High-Enthalpy Shock Tunnel

2018 ◽  
Author(s):  
Yunpeng Wang ◽  
Zonglin Jiang ◽  
Honghui Teng
Keyword(s):  
Natural Frequencies ◽  
Aerodynamic Drag ◽  
Aerodynamic Force ◽  
Mechanical Vibration ◽  
Low Frequency ◽  
Shock Tunnel ◽  
Test Time ◽  
Test Duration ◽  
Flow State ◽  
High Enthalpy

Shock tunnels create very high temperature and pressure in the nozzle plenum and flight velocities up to Mach 20 can be simulated for aerodynamic testing of chemically reacting flows. However, this application is limited due to milliseconds of its test duration (generally 500 μs–20 ms). For the force test in the conventional hypersonic shock tunnel, because of the instantaneous flowfield and the short test time [1–4], the mechanical vibration of the model-balance-support (MBS) system occurs and cannot be damped during a shock tunnel run. The inertial forces lead to low frequency vibrations of the model and its motion cannot be addressed through digital filtering. This implies restriction on the model’s size and mass as its natural frequencies are inversely proportional the length scale of the model. As to the MBS system, sometimes, the lowest natural frequency of 1 kHz is required for the test time of typically 5 ms in order to get better measurement results [2]. The higher the natural frequencies, the better the justification for the neglected acceleration compensation. However, that is very harsh conditions to design a high-stiffness MBS structure, particularly a drag balance. Therefore, it is very hard to carried out the aerodynamic force test using traditional wind tunnel balances in the shock tunnel, though its test flow state with the high-enthalpy is closer to the real flight condition.

scholarly journals Aerodynamic force and moment measurement of 10° half-angle cone in JF12 shock tunnel

2017 ◽  
Vol 30 (3) ◽  
pp. 983-987 ◽  
Author(s):  
Yunfeng LIU ◽  
Yunpeng WANG ◽  
Chaokai YUAN ◽  
Changtong LUO ◽  
Zonglin JIANG
Keyword(s):  
Aerodynamic Force ◽  
Shock Tunnel ◽  
Moment Measurement ◽  
Half Angle

scholarly journals Intelligent Force-Measurement System Use in Shock Tunnel

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6179
Author(s):  
Yunpeng Wang ◽  
Zonglin Jiang
Keyword(s):  
Deep Learning ◽  
Measurement System ◽  
Force Measurement ◽  
Aerodynamic Force ◽  
Low Frequency ◽  
Shock Tunnel ◽  
New Method ◽  
Test Results ◽  
Force Measurement System ◽  
The Impact

The inertial vibration of the force measurement system (FMS) has a large influence on the force measuring result of aircraft, especially on some tests carried out in high-enthalpy impulse facilities, such as in a shock tunnel. When force tests are conducted in a shock tunnel, the low-frequency vibrations of the FMS and its motion cannot be addressed through digital filtering because of the inertial forces, which are caused by the impact flow during the starting process of the shock tunnel. Therefore, this paper focuses on the dynamic characteristics of the performance of the FMS. A new method—i.e., deep-learning-based single-vector dynamic self-calibration (DL-based SV-DSC) of an impulse FMS, is proposed to increase the accuracy of aerodynamic force measurements in a shock tunnel. A deep-learning technique is used to train the dynamic model of the FMS in this study. Convolutional neural networks with a simple structure are applied to describe the dynamic modeling so that the low-frequency vibration signals are eliminated from the test results of the shock tunnel. By validation of the force test results measured in a shock tunnel, the current trained model can realize intelligent processing of the balance signals of the FMS. Based on this new method of dynamic calibration, the reliability and accuracy of force data processing are well verified.

scholarly journals Impulse Force Balance for Ultrashort Duration Hypersonic Test Facilities

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
P. Singh ◽  
V. Menezes ◽  
K. J. Irimpan ◽  
H. Hosseini
Keyword(s):  
Impulse Response ◽  
Aerodynamic Force ◽  
Delta Wing ◽  
Shock Tunnel ◽  
Force Balance ◽  
Test Model ◽  
Impulse Response Functions ◽  
Response Functions ◽  
Test Assembly ◽  
Hypersonic Shock

This paper presents the measurement of side force, pitching, and yawing moments on a model, using an accelerometer force balance, in a short duration hypersonic shock tunnel. The test model is a blunt-nosed, flapped delta wing, mounted on a support sting through a force balance. The flexible rubber bushes constituting the balance allow the model to float freely on the sting during the test. The accelerometers were located in the model to record accelerations in the directions of interest. The model was tested in shock tunnel at Mach 8 at different angles of incidence with the freestream. Dynamic calibration of the test assembly was carried out for the acquisition of impulse response functions for the above components of force and moments, using an impulse hammer. The convolution technique was applied to derive the impulse response functions. The accelerometer outputs from the model in the hypersonic freestream were processed using the respective impulse response functions to derive the unknown aerodynamic force and moments. The newly adopted convolution technique has been found very effective for data reduction from accelerometer force balances developed for shock tunnel applications.

Millisecond aerodynamic force measurement with side-jet model in theISL shock tunnel

AIAA Journal ◽  
1993 ◽  
Vol 31 (6) ◽  
pp. 1068-1074 ◽  
Author(s):  
K. W. Naumann ◽  
H. Ende ◽  
G. Mathieu ◽  
A. George
Keyword(s):  
Force Measurement ◽  
Aerodynamic Force ◽  
Shock Tunnel
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