Wind Tunnel Assembly for dynamic pressure characterization

2019 ◽  
Author(s):  
Cesar Roberto de Souza ◽  
Mauro Sergio Braga ◽  
Walter Jaimes Salcedo
Keyword(s):  
Wind Tunnel ◽  
Dynamic Pressure

A New Method of Modeling Underexpanded Exhaust Plumes for Wind Tunnel Aerodynamic Testing

1989 ◽  
Vol 111 (4) ◽  
pp. 748-754
Author(s):  
V. Salemann ◽  
J. M. Williams
Keyword(s):  
Wind Tunnel ◽  
Free Stream ◽  
Dynamic Pressure ◽  
Pressure Ratio ◽  
Area Ratio ◽  
Full Scale ◽  
New Method ◽  
Thrust Coefficient ◽  
Model Scale ◽  
Exhaust Plumes

A new method for modeling hot underexpanded exhaust plumes with cold model scale plumes in aerodynamic wind tunnel testing has been developed. The method is applicable to aeropropulsion testing where significant interaction between the exhaust and the free stream and aftbody may be present. The technique scales the model and nozzle external geometry, including the nozzle exit area, matches the model jet to free-stream dynamic pressure ratio to full-scale jet to free-stream dynamic pressure ratio, and matches the model thrust coefficient to full-scale thrust coefficient. The technique does not require scaling of the internal nozzle geometry. A generalized method of characteristic computer code was used to predict the plume shapes of a hot (γ = 1.2) half-scale nozzle of area ratio 3.2 and of a cold (γ = 1.4) model scale nozzle of area ratio 1.3, whose pressure ratio and area ratio were selected to satisfy the above criteria and other testing requirements. The plume shapes showed good agreement. Code validity was checked by comparing code results for cold air exhausting into a quiescent atmosphere to pilot surveys and shadowgraphs of model nozzle plumes taken in a static facility.

Research on Transonic Wind Tunnel Flutter Test for a Wing Model

2014 ◽  
Vol 1006-1007 ◽  
pp. 26-29
Author(s):  
Li Yu ◽  
Bin Bin Lv ◽  
Hong Tao Guo ◽  
Yu Yan ◽  
Xing Hua Yang ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Dynamic Pressure ◽  
Critical Parameters ◽  
Test Results ◽  
Wing Model ◽  
Calibration And Verification ◽  
Observation Method ◽  
Prediction Approach ◽  
Direct Observation Method ◽  
Transonic Wind Tunnel

This paper adopts self-designed wing model to conduct flutter test on subsonic and transonic, and obtains flutter characteristic of the model, and the test results are used for calibration and verification of flutter procedures. The sub-critical extrapolation is used to obtain the flutter sub-critical parameters and the direct observation method is used to obtain comparison of results. Error of results obtained by the two approaches does not exceed 5%, and validates reliability of the sub-critical prediction approach in continuous adjusted dynamic pressure flutter test.

scholarly journals Experimental and Numerical Studies on Static Aeroelastic Behaviours of a Forward-Swept Wing Model

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yan Ouyang ◽  
Kaichun Zeng ◽  
Xiping Kou ◽  
Yingsong Gu ◽  
Zhichun Yang
Keyword(s):  
Wind Tunnel ◽  
Dynamic Pressure ◽  
Wind Tunnel Test ◽  
Swept Wing ◽  
Lattice Method ◽  
Model Calculations ◽  
Wind Tunnel Tests ◽  
Model Based ◽  
Wing Model ◽  
Fidelity Model

The static aeroelastic behaviours of a flat-plate forward-swept wing model in the vicinity of static divergence are investigated by numerical simulations and wind tunnel tests. A medium fidelity model based on the vortex lattice method (VLM) and nonlinear structural analysis is proposed to calculate the displacements of the wing structure with large deformation. Follower forces effect and geometric nonlinearity are considered to calculate the deformation of the wing by finite element method (FEM). In the wind tunnel tests, the divergence dynamic pressure is predicted by the Southwell method, and the static aeroelastic displacement is measured by a photogrammetric method. The results obtained by the medium fidelity model calculations show reasonable agreement with wind tunnel test results. A high fidelity model based on coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) predicts better results of the wing tip displacement when the freestream dynamic pressure is approaching the divergence dynamic pressure.

Effects of Sensor Shape on Oscillating Pressure Measurements With Wind-Tunnel Test Confirmation

2006 ◽  
Author(s):  
David W. Wu ◽  
Hwang Choe
Keyword(s):  
Wind Tunnel ◽  
Pressure Sensor ◽  
Pressure Wave ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Wind Tunnel Test ◽  
Flow Patterns ◽  
External Flow ◽  
Pressure Measurements ◽  
Significant Correction

This paper summarizes the effects of the pressure sensor shape on the dynamic oscillating pressure measurements when the pressure wave modulating along the steam/air flow path is to be characterized. In the study presented in the paper, a three-dimensional CFD model of the external flow around the protruding, dome-shaped sensor was developed to evaluate the effects of the sensor shape on the external flow pattern, and the detailed flow patterns were studied with this protruding, dome-shaped sensors and compared with the flow patterns for the flush mounted sensors. Then, a one-dimensional analysis was done to predict that the dynamic pressures measured with the protruding sensor do not require significant correction, and this was later supported by wind tunnel tests. The amplitude of the dynamic pressure measured on the protruding sensor was determined to be ranging from 0 to 8% higher than measured by a flush mounted pressure sensor. The frequency of the pressure wave is not affected by the presence of the protrusion.

scholarly journals Aerodynamic interference of wind flow around three cylindrical bodies with surface roughness

2020 ◽  
Vol 313 ◽  
pp. 00051
Author(s):  
Michael Macháček ◽  
Shota Urushadze ◽  
Stanislav Pospíšil ◽  
Arsenii Trush ◽  
Miroš Pirner
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Surface Roughness ◽  
Wind Tunnel ◽  
Dynamic Pressure ◽  
Wind Loading ◽  
Wind Flow ◽  
Local Dynamic ◽  
Complex Phenomenon ◽  
Aerodynamic Interference

The aerodynamic interference effect is an important and complex phenomenon that can modified wind flow around structures in a group and wind loading on structures can significantly increase. Three cylindrical buildings in one row with a rough surface and surrounding lower minor buildings were studied by experimental measurement in wind tunnel with a turbulent boundary layer. The experimental study was focused on aerodynamical forces, local dynamic pressure on a facade of the buildings, and visualization of wind flow around buildings.

Flutter Optimized Design for a Aircraft Horizontal Tail Base on Optimus Software

2014 ◽  
Vol 684 ◽  
pp. 58-63
Author(s):  
Da Qian Zhang ◽  
Xiao Dong Tan ◽  
Zi Lei Zhang ◽  
Xin Ping Fu
Keyword(s):  
Finite Element ◽  
Wind Tunnel ◽  
Similarity Theory ◽  
Dynamic Pressure ◽  
Unsteady Aerodynamics ◽  
Element Model ◽  
Scale Model ◽  
Optimized Design ◽  
Lattice Method ◽  
Doublet Lattice Method

Based on the similarity theory, the horizontal tail scale model is designed and manufactured. Subsonic doublet lattice method is used to calculate unsteady aerodynamics, V-g method is used to solve the flutter determinant. Optimus software is used to optimize the thickness of the skin. The constraint condition is the frequency, MAC value and flexibility, and the objective function is flutter dynamic pressure. Flutter velocity of horizontal tail model optimized decreased 6%,and flutter frequency increased greatly. Horizontal tail scale model was test in wind tunnel. The finite element calculate results was very close with wind tunnel results, which verify the correctness of the finite element model and optimization models.

scholarly journals Pengukuran Kualitas Kecepatan Angin pada Terowongan Angin di ILST BBTA3

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Novan Risnawan ◽  
F. Andree Yohanes ◽  
Sunarno Sunarno ◽  
Hetty Novianti ◽  
Yusron Feriadi
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Dynamic Pressure ◽  
Reference Value ◽  
Pitot Tube ◽  
Calibration Coefficient ◽  
Result Show ◽  
Flow Quality ◽  
Low Speed Wind Tunnel

AbstractCalibration check of Indonesia Low Speed Wind Tunnel (ILST) flow reference value have been performed at the beginning of 2018. Calibration check have been conducted to the calibration coefficient of predicted freestream static and dynamic pressure. This wind tunnel reference values is reffered to the static and dynamic pressure of a reference pitot tube that is installed at the center of turn table inside the test section. The test is conducted in empty test section. The calibration check result is very close to the previous values. This result show that flow quality of ILST wind tunnel is still maintained well for aerodynamic testing purposes.Keywords: Wind tunnel calibration, tunnel reference value. AbstrakPengecekan hasil kalibrasi besaran-besaran acuan aliran terowongan angin ILST telah selesai dilakukan pada awal tahun 2018. Pengecekan kalibrasi dilakukan terhadap koefisien kalibrasi tekanan statik dan tekanan dinamik terprediksi. Koefisien-koefisien referensi terowongan angin ini disesuaikan dengan tekanan statik dan tekanan dinamik yang dibaca oleh pitot tube acuan yang dipasang di tengah turn table di dalam seksi uji. Pengukuran dilakukan pada kondisi seksi uji kosong (empty test section). Hasil pengecekan kalibrasi acuan ini sangat dekat dengan hasil sebelumnya. Hasil kegiatan ini secara umum menunjukkan bahwa kualitas aliran terowongan angin ILST masih terpelihara dengan baik untuk keperluan pengujian aerodinamik.Kata Kunci : Kalibrasi terowongan angin, referensi terowongan angin. 

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