scholarly journals Design, Construction and Testing of a Desktop Supersonic Wind Tunnel

2005 ◽  
Vol 4 (2) ◽  
Author(s):  
Vi Rapp ◽  
Jennifer Jacobsen ◽  
Mark Lawson ◽  
Andrew Parker ◽  
Kuan Chen
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Compressible Flows ◽  
Supersonic Flows ◽  
Load Cell ◽  
Test Facility ◽  
Supersonic Wind Tunnel ◽  
Tunnel System ◽  
Design Construction ◽  
Good Agreement

A mobile and affordable, miniature wind tunnel to aid students in studying high-speed compressible flows was constructed and tested. Millimeter-sized nozzles of different contours were fabricated to produce supersonic flows at Mach 2. The complete system consists of a converging-diverging nozzle, a load cell, pressure and temperature sensors, a tank to store high-pressure gases, and a computer-aided data acquisition system. The wind tunnel system is mounted to a cart, making it convenient to move. This test facility allows students to study and test supersonic flows in a safer environment while eliminating the high costs for a full-sized facility. Gas pressure was measured at various locations in the nozzle. A load cell consisting of four cantilever beams was constructed and used to determine the thrust of the nozzle. Data collected from each nozzle was compared to numerical simulations. In all cases, the simulations were in good agreement with the experimental data.

Multi-Angular Flame Measurements and Analysis in a Supersonic Wind Tunnel Using Fiber Based Endoscopes

2015 ◽  
Author(s):  
Lin Ma ◽  
Andrew J. Wickersham ◽  
Wenjiang Xu ◽  
Scott J. Peltier ◽  
Timothy M. Ombrello ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Thermal Management ◽  
High Speed ◽  
Flow Structures ◽  
Data Sets ◽  
Propulsion Systems ◽  
Supersonic Wind Tunnel ◽  
Optical Access ◽  
Equipment Cost ◽  
Pod Analysis

This paper reports new measurements and analysis made in the Research Cell 19 supersonic wind-tunnel facility housed at the Air Force Research Laboratory. The measurements include planar chemiluminescence from multiple angular positions obtained using fiber based endoscopes (FBEs) and the accompanying velocity fields obtained using particle image velocimetry (PIV). The measurements capture the flame dynamics from different angles (e.g., the top and both sides) simultaneously. The analysis of such data by proper orthogonal decomposition (POD) will also be reported. Non-intrusive and full-field imaging measurements provide a wealth of information for model validation and design optimization of propulsion systems. However, it is challenging to obtain such measurements due to various implementation difficulties such as optical access, thermal management, and equipment cost. This work therefore explores the application of FBEs for non-intrusive imaging measurements in supersonic propulsion systems. The FBEs used in this work are demonstrated to overcome many of the practical difficulties and significantly facilitate the measurements. The FBEs are bendable and have relatively small footprints (compared to high-speed cameras), which facilitates line-of-sight optical access. Also, the FBEs can tolerate higher temperatures than high-speed cameras, ameliorating the thermal management issues. Lastly, the FBEs, after customization, can enable the capture of multiple images (e.g., images of the flowfields at multi-angles) onto the same camera chip, greatly reducing the equipment cost of the measurements. The multi-angle data sets, enabled by the FBEs as discussed above, were analyzed by POD to extract the dominating flame modes when examined from various angular positions. Similar analysis was performed on the accompanying PIV data to examine the corresponding modes of the flowfields. The POD analysis provides a quantitative measure of the dominating spatial modes of the flame and flow structures and is an effective mathematical tool to extract key physics from large data sets such as the high-speed measurements collected in this study. However, past POD analysis has been limited to data obtained from one orientation only. The availability of data at multiple angles in this study is expected to provide further insights into the flame and flow structures in high-speed propulsion systems.

scholarly journals Geometric Effects Analysis and Verification of V-Shaped Support Interference on Blended Wing Body Aircraft

2020 ◽  
Vol 10 (5) ◽  
pp. 1596
Author(s):  
Xin Xu ◽  
Qiang Li ◽  
Dawei Liu ◽  
Keming Cheng ◽  
Dehua Chen
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Pitching Moment ◽  
Straight Section ◽  
Test Results ◽  
Wind Tunnel Tests ◽  
Blended Wing Body ◽  
Support Interference ◽  
Geometric Effects ◽  
Good Agreement

A special V-shaped support for blended wing body aircraft was designed and applied in high-speed wind tunnel tests. In order to reduce the support interference and explore the design criteria of the V-shaped support, interference characteristics and geometric parameter effects of V-shaped support on blended wing body aircraft were numerically studied. According to the numerical results, the corresponding dummy V-shaped supports were designed and manufactured, and verification tests was conducted in a 2.4 m × 2.4 m transonic wind tunnel. The test results were in good agreement with the numerical simulation. Results indicated that pitching moment of blended wing body aircraft is quite sensitive to the V-shaped support geometric parameters, and the influence of the inflection angle is the most serious. To minimize the pitching moment interference, the straight-section diameter and inflection angle should be increased while the straight-section length should be shortened. The results could be used to design special V-shaped support for blended wing body aircraft in wind tunnel tests, reduce support interference, and improve the accuracy of test results.

Effective Body Shape for Reducing Yawing Moment in Cross Wind

2011 ◽  
Author(s):  
Akitoshi Matsui ◽  
Koichi Hishida
Keyword(s):  
Wind Tunnel ◽  
Flow Structure ◽  
High Speed ◽  
Body Shape ◽  
Numerical Data ◽  
Side Surface ◽  
Load Cell ◽  
Side Force ◽  
Driving Stability ◽  
Shape Changes

Reductions of the side force and the connected yawing moment are of significance for driving stability under cross wind. This paper shows the suitable body shape under unsteady cross wind for reducing side force and yawing moment. Numerically, the shape changes such as rounded and/or cut off corners and patterned indented side surface under steady cross wind are evaluated, using k-ε model. The adequate shapes from the numerical data are experimentally validated under steady and unsteady cross wind in a wind tunnel. Flow structure and, side force and yawing moment are examined by High-speed PIV and a three-component load cell, respectively.

Low-Turbulence High-Speed Wind Tunnel for the Determination of Cascade Shock Losses

1979 ◽  
Author(s):  
J. A. Slovisky ◽  
W. B. Roberts ◽  
D. M. Sandercock
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Axial Compressor ◽  
Pressure Probe ◽  
Supersonic Wind Tunnel ◽  
Smoke Flow ◽  
Contraction Ratio ◽  
Curved Shock Waves ◽  
Visualization Techniques

A low turbulence high-speed wind tunnel, using anti-turbulence screening and a 100:1 contraction ratio, has been found suitable for high-speed smoke flow visualization. The location and strength of normal, oblique, and curved shock waves generated by transonic or supersonic wind tunnel flow over airfoils or through axial compressor cascades is determined by combined shadowgraph and smokelines visualization techniques without the interference effects caused by intrusive probes. The Reynolds number based on chord varied between 50,000 and 106. Preliminary results are compared with the relevant theory and data gathered using a total pressure probe.

scholarly journals Test Facility for High-Speed Probe Calibration

2019 ◽  
Vol 213 ◽  
pp. 02033
Author(s):  
Tomáš Jelínek ◽  
Erik Flídr ◽  
Martin Němec ◽  
Jan Šimák
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Total Pressure ◽  
High Speed ◽  
Test Facility ◽  
Nozzle Outlet ◽  
Wide Range ◽  
Mach Numbers ◽  
Probe Calibration ◽  
Subsonic Nozzle

A new test facility was built up as a part of a closed-loop transonic wind tunnel in VZLU´s High-speed Aerodynamics Department. The wind tunnel is driven by a twelve stage radial compressor and Mach and Reynolds numbers can be changed by the compressor speed and by the total pressure in the wind tunnel loop by a set of vacuum pumps, respectively. The facility consists of an axisymmetric subsonic nozzle with an exit diameter de = 100 mm. The subsonic nozzle is designed for regimes up to M = 1 at the nozzle outlet. At the nozzle inlet there is a set of a honeycomb and screens to ensure the flow stream laminar at the outlet of the nozzle. The subsonic nozzle can be supplemented with a transonic slotted nozzle or a supersonic rigid nozzle for transonic and supersonic outlet Mach numbers. The probe is fixed in a probe manipulator situated downstream of the nozzle and it ensures a set of two perpendicular angles in a wide range (±90°). The outlet flow field was measured through in several axial distances downstream the subsonic nozzle outlet. The total pressure and static pressure was measured in the centreline and the total pressure distribution in the vertical and horizontal plane was measured as well. Total pressure fluctuations in the nozzle centreline were detected by a FRAP probe. From the initial flow measurement in a wide range of Mach numbers the best location for probe calibration was chosen. The flow field was found to be suitable for probe calibration.

Multi-angular Flame Measurements and Analysis in a Supersonic Wind Tunnel Using Fiber-Based Endoscopes

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Lin Ma ◽  
Andrew J. Wickersham ◽  
Wenjiang Xu ◽  
Scott J. Peltier ◽  
Timothy M. Ombrello ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Thermal Management ◽  
High Speed ◽  
Flow Fields ◽  
Flow Structures ◽  
Data Sets ◽  
Propulsion Systems ◽  
Supersonic Wind Tunnel ◽  
Equipment Cost ◽  
Pod Analysis

This paper reports new measurements and analysis made in the Research Cell 19 supersonic wind-tunnel facility housed at the Air Force Research Laboratory. The measurements include planar chemiluminescence from multiple angular positions obtained using fiber-based endoscopes (FBEs) and the accompanying velocity fields obtained using particle image velocimetry (PIV). The measurements capture the flame dynamics from different angles (e.g., the top and both sides) simultaneously. The analysis of such data by proper orthogonal decomposition (POD) will also be reported. Nonintrusive and full-field imaging measurements provide a wealth of information for model validation and design optimization of propulsion systems. However, it is challenging to obtain such measurements due to various implementation difficulties such as optical access, thermal management, and equipment cost. This work therefore explores the application of the FBEs for nonintrusive imaging measurements in the supersonic propulsion systems. The FBEs used in this work are demonstrated to overcome many of the practical difficulties and significantly facilitate the measurements. The FBEs are bendable and have relatively small footprints (compared to high-speed cameras), which facilitates line-of-sight optical access. Also, the FBEs can tolerate higher temperatures than high-speed cameras, ameliorating the thermal management issues. Finally, the FBEs, after customization, can enable the capture of multiple images (e.g., images of the flow fields at multi-angles) onto the same camera chip, greatly reducing the equipment cost of the measurements. The multi-angle data sets, enabled by the FBEs as discussed above, were analyzed by POD to extract the dominating flame modes when examined from various angular positions. Similar analysis was performed on the accompanying PIV data to examine the corresponding modes of the flow fields. The POD analysis provides a quantitative measure of the dominating spatial modes of the flame and flow structures, and is an effective mathematical tool to extract key physics from large data sets as the high-speed measurements collected in this study. However, the past POD analysis has been limited to data obtained from one orientation only. The availability of data at multiple angles in this study is expected to provide further insights into the flame and flow structures in high-speed propulsion systems.

Design, Fabrication, and Realization of a Supersonic Wind Tunnel for Educational Purposes

2009 ◽  
Vol 37 (4) ◽  
pp. 286-303 ◽  
Author(s):  
Mohammed K. Ibrahim ◽  
A. F. Abohelwa ◽  
Galal B. Salem
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Compressible Flows ◽  
Basic Education ◽  
Design Parameters ◽  
High Tech ◽  
Design Phase ◽  
Supersonic Wind Tunnel ◽  
Design Error ◽  
Standard Textbook

The supersonic wind tunnel is an indispensable facility for basic education in any course that covers compressible flows and one of the main pillars of any aerodynamic laboratory. The introduction of a supersonic wind tunnel at the aerodynamics laboratory of the Aerospace Engineering Department at Cairo University had often been postponed and was hindered by a lack of funds for the purchase of foreign equipment and expertise. Thoughts therefore turned to building such facility instead of buying it, substituting high-tech and complex foreign equipment for locally produced equipment, and ‘thinking out of the box’ to make the most use of available resources, even when this led to some unconventional applications. An extensive scheme for the design, fabrication, and realization of a multi-Mach number ( M = 1.5, 2, and 2.5) supersonic wind tunnel for laboratory experiments is proposed in this paper. The proposed scheme is simple, detailed and multi-level; it starts by utilizing one-dimensional isentropic flow theory for the conceptual design phase and makes full use of computational fluid dynamics at the detailed design phase. This ensured that we had a working design before we embarked on the manufacture of any components, which would have been costly to modify had there been any design error. A parametric study has been carried out for a number of design parameters, using numerical simulations. After the design and fabrication, a number of successful standard textbook experiments, for Mach number 2, were carried out as validation for the proposed scheme. The results showed good agreement with the theoretical predictions.

Videogrammetry of the Model’s Attitude in Wind Tunnel Testing

2012 ◽  
Vol 190-191 ◽  
pp. 1273-1277 ◽  
Author(s):  
Zheng Yu Zhang ◽  
Zhong Xiang Sun ◽  
Xu Hui Huang ◽  
Yan Sun
Keyword(s):  
Standard Deviation ◽  
Wind Tunnel ◽  
Drag Coefficient ◽  
Systematic Error ◽  
Measurement System ◽  
High Speed ◽  
Wind Tunnel Test ◽  
Wind Tunnel Testing ◽  
Supersonic Wind Tunnel ◽  
Tunnel Testing

The advanced precision of drag coefficient is 0.0001 for the high speed wind tunnel test of measuring forces, the model’s angle of attack precision is ≤0.01°following errors distribution. A videogrammetric method of model’s attitude is therefore proposed, its uncertainty is investigated, and a compensation method of its systematic error is also presented by this paper. The three engineering videogrammetric experiments of attack angle in 2 meter supersonic wind tunnel testing have demonstrated that measuring standard deviation of videogrammetric measurement system established by this paper is ≤0.0094°, in addition it neither destroys the model’s shape, nor changes the stiffness or strength, so it is useful and effective.

Preliminary Tests of High Speed PIV Measurements in a Ludwieg-Tube Supersonic Wind Tunnel

2007 ◽  
Author(s):  
Khalid Juhany ◽  
A. Darji ◽  
Mohammed Zahrani ◽  
Husam Husieni ◽  
Majed Behairi ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Supersonic Wind Tunnel ◽  
Piv Measurements ◽  
Ludwieg Tube

A Note on the Theory of the Constant-Area Mixing of Compressible Flows as Applied to High-Speed Wind Tunnel Design

1953 ◽  
Vol 4 (2) ◽  
pp. 164-178
Author(s):  
F. G. Irving
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Compressible Flows ◽  
Main Stream ◽  
Cross Sectional ◽  
Induction Type ◽  
Tunnel Design ◽  
Mach Numbers ◽  
The One ◽  
Working Section

SummaryThe one-dimensional equations governing the mixing of compressible flows in a channel of constant cross-sectional area are derived and are used to investigate the running of an induction-type high-speed wind tunnel. While in practice it is usually difficult to achieve working section Mach numbers greater than about 1.8 to 20 in this type of tunnel, this simple theory gives no obvious reason for this and indicates that higher Mach numbers should be attainable.It is also shown that an increase in efficiency is predicted, particularly at the higher supersonic Mach numbers, if the injected stream enters the mixing section at the same Mach number as that of the working section main stream.

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