Web Services Wind Tunnel: On Performance Testing Large-Scale Stateful Web Services

Author(s):  
Marcelo De Barros ◽  
Jing Shiau ◽  
Chen Shang ◽  
Kenton Gidewall ◽  
Hui Shi ◽  
...  
2014 ◽  
Vol 118 (1209) ◽  
pp. 1349-1358 ◽  
Author(s):  
N. Allen ◽  
S. Lawson ◽  
M. Maina ◽  
J. Alderman

Abstract The current drive towards reducing the environmental impact of aircraft necessitates the ability to evaluate techniques for promoting natural laminar flow in a large scale wind tunnel facility. A test was undertaken on the M2355 variable sweep model to obtain temperature sensitive paint (TSP) and hot-film data from which the transition locations at a range of sweep angles and flow conditions could be identified. The TSP technique has been shown to be a reliable method for determining transition on suitably treated wind tunnel models. Pressure data were also acquired and interpolated to provide the input to the laminar boundary layer code, BL2D, the output from which was used in the linear stability analysis code, CoDS, to calculate the N-factor for the ARA TWT (Transonic Wind Tunnel) facility. Two sets of N-factors were calculated, firstly using incompressible analysis with stationary crossflow and secondly using compressible analysis with travelling crossflow. In both analyses the Tollmien-Schlichting and crossflow cases were calculated together, rather than separating the cases before running the analysis. The resulting N-factors indicate a degree of scatter typical for experimental data. The N-factor based on incompressible theory for crossflow was found to be approximately 7 and for Tollmien-Schlichting (T-S), approximately 11. The results of the wind tunnel test and the analysis carried out are considered to be the first steps towards establishing a methodology for performance testing, in atmospheric tunnels such as the TWT, for aircraft designed to have significant regions of laminar flow. The project has also provided a body of experimental test data which will be valuable for future research into development and validation of laminar flow methods.


2016 ◽  
Vol 142 (10) ◽  
pp. 04016042 ◽  
Author(s):  
M. A. Perez ◽  
W. C. Zech ◽  
X. Fang ◽  
J. G. Vasconcelos

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4348 ◽  
Author(s):  
Wei Liu ◽  
Xin Ma ◽  
Xiao Li ◽  
Yi Pan ◽  
Fuji Wang ◽  
...  

Nowadays, due to the advantages of non-contact and high-speed, vision-based pose measurements have been widely used for aircraft performance testing in a wind tunnel. However, usually glass ports are used to protect cameras against the high-speed airflow influence, which will lead to a big measurement error. In this paper, to further improve the vision-based pose measurement accuracy, an imaging model which considers the refraction light of the observation window was proposed. In this method, a nonlinear camera calibration model considering the refraction brought by the wind tunnel observation window, was established first. What’s more, a new method for the linear calibration of the normal vector of the glass observation window was presented. Then, combining with the proposed matching method based on coplanarity constraint, the six pose parameters of the falling target could be calculated. Finally, the experimental setup was established to conduct the pose measurement study in the laboratory, and the results satisfied the application requirements. Besides, experiments for verifying the vision measurement accuracy were also performed, and the results indicated that the displacement and angle measurement accuracy approximately increased by 57% and 33.6%, respectively, which showed the high accuracy of the proposed method.


AIAA Journal ◽  
2017 ◽  
Vol 55 (10) ◽  
pp. 3611-3616 ◽  
Author(s):  
M. A. Mustafa ◽  
N. J. Parziale ◽  
M. S. Smith ◽  
E. C. Marineau

Author(s):  
S. Blaser ◽  
J. Meyer ◽  
S. Nebiker ◽  
L. Fricker ◽  
D. Weber

Abstract. Advances in digitalization technologies lead to rapid and massive changes in infrastructure management. New collaborative processes and workflows require detailed, accurate and up-to-date 3D geodata. Image-based web services with 3D measurement functionality, for example, transfer dangerous and costly inspection and measurement tasks from the field to the office workplace. In this contribution, we introduced an image-based backpack mobile mapping system and new georeferencing methods for capture previously inaccessible outdoor locations. We carried out large-scale performance investigations at two different test sites located in a city centre and in a forest area. We compared the performance of direct, SLAM-based and image-based georeferencing under demanding real-world conditions. Both test sites include areas with restricted GNSS reception, poor illumination, and uniform or ambiguous geometry, which create major challenges for reliable and accurate georeferencing. In our comparison of georeferencing methods, image-based georeferencing improved the median precision of coordinate measurement over direct georeferencing by a factor of 10–15 to 3 mm. Image-based georeferencing also showed a superior performance in terms of absolute accuracies with results in the range from 4.3 cm to 13.2 cm. Our investigations showed a great potential for complementing 3D image-based geospatial web-services of cities as well as for creating such web services for forest applications. In addition, such accurately georeferenced 3D imagery has an enormous potential for future visual localization and augmented reality applications.


Author(s):  
Alex Ng ◽  
Shiping Chen

Performance testing is one of the vital activities spanning the whole life cycle of software engineering. As a result, there are a considerable number of performance testing products and open source tools available. It has been observed that most of the existing performance testing products and tools are either too expensive and complicated for small projects, or too specific and simple for diverse performance tests. In this chapter, we will present an overview of existing performance test products/tools, provide a summary of some of the contemporary system performance testing frameworks, and capture the key requirements for a general-purpose performance testing framework. Based on our previous works, we propose a system performance testing framework which is suitable for both simple and small, as well as complicated and large-scale performance testing projects. The core of our framework contains an abstraction to facilitate performance testing by separating the application logic from the common performance testing functionality, and a set of general-purpose data model.


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