Search

感圧塗料（Pressure-Sensitive Paint :PSP）計測はこれまで1kPa～500kPaの圧力レンジで利用され，風洞において航空宇宙機モデル上の圧力場計測が行われてきた．本研究では，PSP計測技術利用拡大に向けて，高Kn（Knudsen Number, Kn）数流れへの適用可能性を調べるため，超低圧力レンジでの圧力感度特性を評価した．本レポートではその結果について報告する．, Pressure-Sensitive Paint (PSP) technique has been developed for acquiring surface pressure images on a model in the wind tunnel tests. Generally, PSP measurement has been conducted with a pressure range from 1kPa to 500kPa. In this study, the characteristics of PSP in the ultra low pressure range (10(exp -3) - 10(exp 2) Pa) were evaluated for visualization of high Knudsen (Kn) number flowfields., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations

This paper describes unsteady behavior of shock waves around supersonic intake at Mach 2.5. The experiment carried out by small shock tunnel. Flow visualization was conducted with shadowgraph method and pressure-sensitive paint (PSP). A fast response anodized aluminum pressure-sensitive paint (AA-PSP) was used in the experiment. And to confirm the valid of experimental results, numerical calculation were performed by compressible Navier-Stokes equations with Weighted Average Flux (WAF) method and Adaptive Mesh Refinement (AMR). From the results of shock wave structures and pressure distribution, we confirmed shock waves behavior around the supersonic intake model at subcritical state. It considers occurring buzz., 形態: カラー図版あり, Meeting Information: 5th Symposium on Integrating CFD and Experiments in Aerodynamics (October 3-5, 2012, Chofu Aerospace Center, Japan Aerospace Exploration Agency (JAXA)), Chofu, Tokyo, Japan, Physical characteristics: Original contains color illustrations

Film cooling is widely used to protect gas turbine blades and vanes from the extremelly hot gases leaving the combustion chamber. Over the past decades, film cooling on blades, vanes and end-wall has been widely studied. In order to understand and define the process several measurement techniques have been developed. Given that numerical simulations are yet not accurate enough, as they are not able to take into account all the parameters that affect such process, the interest in experimental measurements has grown. Several measurement techniques have been used in order to calculate the film cooling effectiveness and being able to understand how the different variables affect to the overall efficiency of the process. Trying to determine film cooling efectiveness, Pressure Sensitive Paints (PSP) have been recently adapted and used. PSP have been developed since 1980s for different fluid mechanics and aerodynamic testing expermients. Since 1990s the technique is mature enough to be used and achieve high quality results in industrial wind tunnels. PSP is an absolute transducer able to convert units of surface pressure into units of light. PSP systems are able to give high precision measurements with full-surface coberture and high resolution. As PSP is a non-intrusive measurement technique, once it is designed it can be relatively easy adapted to new systems. This Master Thesis focuses on PSP technique, and aims to give a global explanation of the technique as well as a clear and precise definition of each part of the process. The main goal for this project is to design, build and test a PSP system. In order to test the PSP system, a test setup has been design, consisting in a flat test plate with cooling holes. The design of the process has been thought to be tested in the small Wind tunnel owned by the department Gasturbinen, Luft- und Raumfahrtantriebe (GLR) in the Technische Universität am Darmstadt (TUD). Although the long term objective is to adapt such system to, Outgoing

Measurement of the static-pressure distribution over the surface of a rotor disk was attempted using pressure sensitive paint (PSP). A uniform stress, high speed rotor disk, fitted with a shock generator, was built, installed and operated at speeds in excess of 20,000 RPM by a Hamilton Standard turbine driven fuel pump. A once per revolution trigger signal was converted to a transistor to transistor logic (TTL) format and used to gate an intensified charged coupled device (CCD) video camera. Multiple low intensity level camera exposures were integrated and captured to produce a single usable image. Ten captured images were averaged to increase the image's signal to noise ratio and the result was used to produce an image ratio with respect to a static reference condition. Finally, a pseudo coloring process was used to develop a color image that related intensities to both temperature and pressure distributions in accordance with the Stern-Volmer relation. Paint stripping and temperature dependence prevented the measurement of pressure at transonic speeds. The test bed facility and acquisition techniques developed here could now be used to overcome those limitations, http://archive.org/details/pressuresensitiv109458849, Lieutenant Commander, United States Navy, Approved for public release; distribution is unlimited.

In order to obtain quantitative surface pressure measurements of a transonic compressor rotor using pressure sensitive paint (PSP), the temperature dependence of the paint must be taken into consideration. In the present study, a calibration chamber was built and instrumented such that pressure and temperature could be controlled independently. Photodiodes were used to measure the intensity of light emitted by the PSP. An acquisition program was developed to record the necessary calibration data to obtain an analytical representation of the luminescent response of the pressure-sensitive paint over a range of pressures and temperatures characteristic of transonic fans, http://archive.org/details/calibrationtodet109457642, Ensign, United States Navy, Approved for public release; distribution is unlimited.

Pressure-sensitive paint measurement on a transonic compressor rotor required the prior development of phase-locked cumulative imaging using a disk- rotor driven by a high-speed Hamilton-Standard turbine as a developmental test- bed. The turbine was installed in a protective housing in the Gas Dynamics Laboratory and connected to an 8000 cu ft, 300 psi air supply. An hydraulic pump provided bearing lubrication. A once per revolution trigger signal was produced from a light-emitting diode and PIN photodiode pair. The imaging system consisted of an intensified CCD video camera externally triggered by the 1/rev signal via a waveform shaping circuit designed for the present application. Images were captured at camera gate speeds calculated to eliminate pixel blur and image integration times were varied to optimize image intensity and spatial resolution. Structural and modal analyses of the disk-rotor were conducted and a simplified numerical model of the flow was computed. Ratioed, colored images were produced for wheel speeds to 20,000 RPM. The effect of the radially varying stagnation temperature was evident, underscoring the importance of quantifying and accounting for the PSP temperature sensitivity so that quantitative pressure data may be obtained. Recommendations for a follow-on program are reported, http://archive.org/details/pressuresensitiv109458850, Lieutenant, United States Navy, Approved for public release; distribution is unlimited.

Time response of pressure-sensitive luminescent coatings has been investigated theoretically and experimentally. The present coating consists of a thin anodized aluminum layer and luminophores. The layer is formed onto the surface of pure aluminum by an electro-chemical process. The luminophores are adsorbed onto the surface of the layer via chemical and physical adsorption. A method of making this coating is described in detail. The theoretical analysis shows that the effective diffusion coefficient for oxygen permeation in the anodized aluminum layer is up to 1 × 10^-5 m^2/s. This implies that the present coating should have the response time of the order of microseconds. For three kinds of luminophores, two porphyrin compounds and a ruthenium(II) complex, the response to a step change in pressure was studied using a pressure jump apparatus and a shock tube. It has been found that the response time of coating with tris(4,7-diphenylphenanthroline)ruthenium(II) ([Ru(dpp)_3]^2+) is longer than 20 μs, and depends on the thickness of anodized aluminum layer. On the other hand, tetrakis-(4-carboxyphenyl) porphyrin (TCPP) coating has the time response less than 10 μs, which is independent of the thickness of layer.

A new pressure-measurement technique which employs the tools of molecular spectroscopy has recently received considerable attention in the fluid mechanics community. Measurements are made via oxygen-sensitive molecules attached to the surface of interest as a coating, or paint. The pressure-sensitive-paint (PSP) technique is now commonly used in stationary wind-tunnel tests; this thesis presents the extension of the technique to advanced turbomachinery applications. New pressure- and temperature-sensitive paints (TSPs) have been developed for application to a state-of-the-art transonic compressor where pressures up to 2 atm and surface temperatures up to 140° C are expected for the first-stage rotor. PSP and TSP data has been acquired from the suction surface of the first-stage rotor of a transonic compressor operating at its peak-efficiency condition. The shock structure is clearly visible in the pressure image, and visual comparison to the corresponding computational fluid dynamics (CFD) prediction shows qualitative agreement to the PSP data.

A new pressure-measurement technique which employs the tools of molecular spectroscopy has recently received considerable attention in the fluid mechanics community. Measurements are made via oxygen-sensitive molecules attached to the surface of interest as a coating, or paint. The pressure-sensitive-paint (PSP) technique is now commonly used in stationary wind-tunnel tests; this thesis presents the extension of the technique to advanced turbomachinery applications. New pressure- and temperature-sensitive paints (TSPs) have been developed for application to a state-of-the-art transonic compressor where pressures up to 2 atm and surface temperatures up to 140° C are expected for the first-stage rotor. PSP and TSP data has been acquired from the suction surface of the first-stage rotor of a transonic compressor operating at its peak-efficiency condition. The shock structure is clearly visible in the pressure image, and visual comparison to the corresponding computational fluid dynamics (CFD) prediction shows qualitative agreement to the PSP data.