Visualization Of Pressure Distribution Research Articles

Reliable method of aerodynamic analysis using computational fluid dynamics and scaled models in the development process of a Very Light Airplane

In past decades a massive improvement of computational fluid dynamics (CFD) methods and the rapid increase of computational resources made it possible to simulate a lot of phenomena appearing during the flow of fluid around objects. In following paper a reliable method of aerodynamic analysis using both CFD and scaled models in the development process of a Very Light Airplane have been presented. A method of preparing a numerical model of an airplane and the aerodynamic analysis methodology have been shown. A numerical calculations using finite volume method implemented in specialized software were performed. What is more important, to perform the aerodynamic tests in wind tunnels, scaled models of an airplane have been prepared using the modern and fast manufacturing technologies, including 3D printing and CNC machining. The results have been shown in the graphs form of aerodynamic force and moment components as function of angle of attack. During research an influence of structural parts of an airplane on aerodynamic characteristics have been analyzed. The qualitative results of a flow around the aircraft body have been presented in form of parameter distribution maps on the airframe surface have been shown. Visualization of pressure distribution have been extended with path lines visualization of the flow. The research described in the paper is an example of professional and innovative approach to the subject matter.

Emerging Technologies of Flexible Pressure Sensors: Materials, Modeling, Devices, and Manufacturing

AbstractAs an important branch of wearable electronics, flexible pressure sensors have attracted extensive research owing to their wide range of applications, such as human–machine interfaces and health monitoring. To fulfill the requirements for different applications, new material design and device fabrication strategies have been developed in order to manipulate the mechanical and electrical properties and enhance device performance. In this paper, the important progresses in flexible pressure sensor development over recent years are selectively reviewed from a material and application perspective. First, an overview of the fundamental working mechanism and the systematic design approach is presented. Particularly, how the theoretical modeling has been used as an auxiliary tool to achieve better sensing performance is discussed. A number of applications, including human–machine interfaces, electronic skin and health monitoring, and certain application‐driven functions, e.g., pressure distribution visualization and direction‐sensitive force detection, are highlighted. Lastly, various advanced manufacturing methods used for realizing large‐scale fabrication are introduced.

Pressure Sensitive Paint Visualization of Pressure Distribution of Externally Pressurized Circular Thrust Gas Bearing With a Single Gas Supply Hole: Experimental Validation of Variation of Pressure Distribution by Supply Pressure

This study investigated the use of pressure sensitive paint (PSP) as new measuring technique for measuring the pressure distribution of a gas bearing. An externally pressurized circular thrust gas bearing with single gas supply hole was used as the test bearing to investigate the suitability of this technique. The test bearing was 30 mm in diameter, with a gas supply hole of diameter 0.7 mm. A coat of PtTFPP, the substance used as the PSP, was applied to the bearing surface using an air-assisted spray. The PSP luminescence characteristics were calibrated before the tests because of their dependency on temperature and pressure. The pressure distribution was obtained by averaging 50 images captured by a 12-bit complementary metal-oxide semiconductor (CMOS) camera. These experimental results were compared with the results of a numerical analysis based on the divergence formulation method. There was good agreement between the experimental and analytical results, thus demonstrating the effectiveness of using PSP for pressure distribution measurements.

Multi-scale vortical structure analysis on large eddy simulation of dune wake flow

The three-dimensional dune wake flow is evaluated by large eddy simulation at a Reynolds number of 5,534, and validated by time-averaged results of particle image velocimetry measurement at a central streamwise plane. To reveal multi-scale characteristics of vortical structure, the instantaneous velocity, vorticity, and pressure were decomposed into the large-, intermediate- and small-scale components by three-dimensional wavelet multi-resolution technique, the scale of each wavelet component is quantified by two-point autocorrelation function with the central scale of 43, 20 and 9.6 mm, respectively. It is found that large-scale structure determines the formation of separation bubble and makes the most significance to the vorticity. Some intermediate-scale and small-scale streamwise vortices cause the upwelling of vortical structures, and they tend to be more active at the downstream. By visualization of pressure distribution, we can find that pressure distribution is mainly characterized by large-scale structure, and the distribution of small-scale structure can be interfered as a reason why large-scale vortical structure breaks into small vortices at the near outlet region.

回転する冷却ファンの表面圧力分布の可視化

回転する冷却ファンの表面圧力分布の可視化

The visualization of pressure distribution along a plate by jet impingement with a holographic method.

A holographic visualization of the pressure on a plate impinged by an axisymmetric turbulent air jet has been carried out. A subdivided silicon rubber sheet located on the plate was transformed with a pressure of the impinging jet and its displacement was measured by the holographic interferometer. The deformation of the rubber plate has no effect on the flow field because of the small wall displacement of order on the 10-5 m. Fringe patterns of the interferometry correspond to the instantaneous isobaric lines, which correlate well to the ones measured with a semiconducter pressure transducer. On the other hand, when the plate image deformed by an impinging jet is used as the original image, fringe patterns indicate pressure fluctuations. These pressure fluctuation patterns were converted to electric signals by a ccd-camera and microcomputer, and analyzed by a digital image processing method. The flow characteristics of the impinging jet were clarified by this visualization method.