| 1. |
Simultaneous Measurement of Pressure and Temperature by Frequency-Domain Lifetime Imaging Technique
―Measurement Accuracy Comparison of a Single Layer of Luminous Paint and Dual-Layer of Luminous Paint―. |
| 2. |
Development of PSP with Low Temperature Sensitivity for Unsteady Measurement of Back Flow Induced by Surging Using DL-PTSP. |
| 3. |
Improvement of simultaneous measurement method of pressure and temperature fields by DL-PTSP by thinning of coating film. |
| 4. |
Hideo Mori, Takamitsu Kuroki and Haruka Nishiyama, Dependence of Measurement Accuracy and Time Delay of Lifetime-based Dual-layer PSP/TSP on Film Thickness, 13th Pacific Symposium on Flow Visualization and Image Processing (PSFVIP13), 2022.08. |
| 5. |
Hideo MORI, Yutaro KOURA, Takamitsu KUROKI, Development of Lifetime-based Method of dual-layer PSP/TSP for Simultaneous Imaging Measurement of Pressure and Temperature, 19th International Symposium on Flow Visualization, 2021.09, Temperature sensitivity of pressure-sensitive paint (PSP) has been one of the most serious problems for application of PSP. Dual-layer PSP/TSP (DL-PTSP) technique can compensate for the temperature sensitivity of PSP by composite measurement of temperature based on temperature-sensitive paint (TSP) technique. In addition, by applying lifetime-based method to DL-PTSP, the emission from a PSP layer and a TSP layer of DL-PTSP can be separated, because the order of the lifetime of the PSP luminophore, PtTFPP, is larger than that of the TSP luminophore, Ru-phen. This feature enables the simultaneous measurement of pressure and temperature by DL-PTSP with a single-camera equipment. In the previous study by Moon et al., data of emission decay of DL-PTSP for 50 periods of excitation must be accumulated to obtain a set of pressure and temperature data. This study enables to obtain a set of pressure and temperature data from emission decay of DL-PTSP for only one period of excitation, by setting appropriate timing of exposure gate of a high-speed camera. As shown in Figure 1 and 2, temperature and pressure sensitivity of the DL-PTSP is comparable to that of the previous work, while the SN ratio can be increased drastically because of the 50-times efficient data analysis. The result enables imaging measurement of pressure and temperature distribution on surfaces by using DL-PTSP.. |
| 6. |
Temperature dependence of pressure-sensitive paint (PSP) causing relatively large error in pressure measurement is still a serious problem. Dual-layer PSP/TSP (DL-PTSP) method overlaying PSP and temperature-sensitive paint (TSP) enables temperature compensation of PSP by composite measurement of pressure and temperature fields. Previous research by the authors applying the lifetime-based method to DL-PTSP enables simultaneous measurement of pressure and temperature, by separating the luminescence of PSP and TSP using the difference between their luminophore lifetimes, but it needed multiple-cycle measurement to obtain one set of data. In this study, we improve the method to enable to obtain one set of data from single-cycle light excitation and measurement, by modifying the timing of camera gates. The luminescence decay reflecting the lifetime of the PSP layer showed high pressure dependence and high SN ratio. However, the luminescence decay reflecting the lifetime of the TSP layer showed pressure dependence, since the effect of PSP decay cannot be eliminated completely. This problem can be solved by improving the composition of DL-PTSP to control the luminescence intensity ratio of PSP layer and TSP layer.. |
| 7. |
Hideo Mori, Kil-Ju Moon and Yutaro Koura, Intensity-based and Lifetime-based Dual-layer PSP/TSP for Low-speed Flow Fields, 7th Japanese-German Joint Seminar, Molecular Imaging Technology for Interdisciplinary Research, 2019.09, Dual-layer PSP/TSP (DL-PTSP) method can reduce the measurement error of PSP technique caused by temperature sensitivity of PSP. Applying intensity-based calibration method to DL-PTSP is relatively easy, because it does not require either high-speed imaging or pulsed light source. However, overlap of emission spectra of the two luminescent dyes results in insufficient separation of the two emission, reducing the sensitivity of both the PSP component and the TSP component. Lifetime-based calibration enables the separation of emission from the PSP and the TSP by using the large difference in their lifetime, even if their emission spectra overlap each other. On the other hand, insufficient difference in the lifetime may results in the decrease in the sensitivity of them. In this study the effect of the overlap of the emission spectra on the intensity-based calibration of DL-PTSP, and the effect of the difference in the lifetime on the lifetime-based calibration of DL-PTSP are discussed.. |
| 8. |
Hideo Mori, Tomohiro Imazeki, Kil Ju Moon, Temperature compensation for measurement of low-speed internal flow fields using fast-response pressure sensitive paint, ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference, AJKFluids 2019, 2019.08, Because most fast-response pressure sensitive paints (PSP) suffer from temperature sensitivity, causing large error in pressure measurement when spatial non-uniformity of pressure distribution is large. In this study, the two methods of composite measurement of temperature and pressure by using the segment painting of PSP and TSP, and Dual-layer PSP/TSP (DL-PTSP), are applied to measurement of pressure distribution on inner surface of casing of test axial compressor, by using transparent method. We apply a paintable fast-response PSP composed of PtTFPP and silica nanoparticles and polymer-based TSP composed of Ru-phen and PMMA, with opaque, oxygen permeable overcoat, in order to enhance the luminescence intensity of PSP and TSP and avoid overlaying image of rotors inside the casing. When segmented-painting method of PSP and TSP is applied, pitch-wise symmetry is assumed. Therefore, asymmetric temperature distribution causes error in temperature compensation. On the other hand, DL-PTSP method can be used for asymmetric conditions, but sequential measurement of pressure and temperature may cause error in temperature compensation, when temperature distribution on the surface is nonstationary.. |
| 9. |
Configuration optimization of Dual-layer PSP/TSP for simultaneous measurement of pressure and temperature
. |
| 10. |
Hideo Mori, Keishiro Takeda, Kazuya Handa, Tomohiro Imazeki, Kil-Ju Moon, APPLICATION OF FAST-RESPONSE PRESSURE SENSITIVE PAINT FOR MEASUREMENT OF INTERNAL FLOWS, The 11th Pacific Symposium on Flow Visualization and Image Processing, 2017.12, There are still very few applications of pressure sensitive paint (PSP) for measurement of nonstationary pressure distribution of internal flows in mechanical engineering fields. Application method of PSP taking the luminescent images of PSP through the transparent solid body (e.g. shroud wall of turbomachinery) and translucent PSP layer enables to apply PSP to the measurement of internal flows. However, this method results in low S/N, because PSP without opaque white basecoat has low luminescent intensity and overlaying image inside the body through the transparent material and PSP layer cause significant error in taking the luminescent image of PSP. To solve the problem, we have developed the application method of PSP by using an opaque, oxygen-permeable overcoat layer having porous structure made of nanoparticles of boron nitride (BN). This overcoat enables to increase the S/N of PSP in the transparent mode, which is needed for measurement of internal flows. In this study, we apply silica nanoparticle PSP having fast time response, because the pressure distribution on a shroud wall of turbomachinery is intrinsically unsteady. To analyze the effect of the opaque overcoat on the pressure sensitivity and the time response of the PSP, we have compared the properties of the PSP with the overcoat and those of the PSP without the overcoat. As a result, it is clarified that the opaque overcoat of BN nanoparticle does not reduce the pressure sensitivity and the time response of the fast-response PSP, which can detect periodical pressure change of the order of 100Pa and lower than 3 kHz. We have applied the fast-response PSP with the overcoat to the pressure measurement of an inner wall of a test axial compressor with the blade-passing frequency of 520Hz, and the qualitative images of the pressure distribution are obtained. We consider that the most significant source of the error in the pressure measurement is the temperature-dependence of the PSP. Therefore, the simultaneous measurement of temperature distribution is needed to increase the accuracy of the pressure measurement using the PSP.. |
| 11. |
Development of Pressure Distribution Measurement Method on Inner Wall of Turbofan Using Pressure Sensitive Paint
Kazuya HANDA, Keishiro TAKEDA, Tomohiro IMAZEKI, Kil-ju MOON, Hideo MORI
Journal of the Visualization Society of Japan, Vol. 37, Suppl. 2, OS1-1-5. |
| 12. |
Kil-Ju Moon, Hideo Mori, Lifetime-based method of dual-layer PSP/TSP for simultaneous measurement of pressure and temperature using a single camera, The 9th JSME-KSME Thermal and Fluids Engineering Conference, 2017.10, The measurement method using PSP (Pressure Sensitive Paint) is useful to measure the two-dimensional pressure distributions on solid surfaces. However, PSP has not only pressure dependence but also temperature dependence. The error of temperature dependence becomes relatively large when measuring low-gauge pressure condition because PSP is absolute pressure sensor. To solve the problem, we designed DL-PTSP (Dual layer PSP/TSP) which stack up TSP (Temperature Sensitive Paint) and PSP layers, to apply TSP to temperature compensation of PSP. In the previous studies, we showed the temperature compensation effect of DL-PTSP with the intensity-based method at non-uniform temperature field in low-gauge pressure condition. However, the intensity-based method using DL-PTSP requires two cameras for simultaneous measurement of temperature and pressure because it requires two optical filters to separate the luminescence of PSP and TSP. In this study, we propose the method of simultaneous measurement using DL-PTSP with lifetime-based method. Big advantage of the method is to enable simultaneous measurement of pressure and temperature with a single camera, because the different lifetime of PSP and TSP enables to separate the luminescence of PSP and TSP without using two optical filters. In addition, DL-PTSP using lifetime-based method does not require wind off images, which may cause significant error of PSP with intensity-based method. At first, we show the dependence of the lifetime of mono-layer PSP and mono-layer TSP on the pressure and the temperature, to clarify the feasibility of the lifetime-based measurement method of PSP and TSP, and we propose the detailed method to separate the luminescence of them. Finally, we apply the lifetime-based method to DL-PTSP and suggest the possibility of temperature compensation of the DL-PTSP.. |
| 13. |
Hideo Mori, Kil-Ju Moon, Application of Lifetime-based Method to Dual-layer PSP/TSP for Simultaneous Measurement of Pressure and Temperature, 6th German-Japanese Joint Seminar, High-speed Molecular Imaging Technology for Interdisciplinary Research, 2017.09. |
| 14. |
Measurement of Pressure Distribution around Internal Flows by Fast-response Pressure Sensitive Paint
Hideo MORI, Keishiro TAKEDA, Kazuya HANDA, Tomohiro IMAZEKI and Kil-Ju MOON. |
| 15. |
Pressure/temperature simultaneous measurement method of dual layer PSP/TSP using lifetime based method
Kil-Ju Moon and Hideo Mori
Journal of the Visualization Society of Japan, Vol. 37, Suppl. 1, F113. |
| 16. |
Measurement of pressure distribution in internal surface of turbo machinery by using pressure sensitive paint. |
| 17. |
Research of pressure sensitive paint using lifetime based method for low pressure flow field. |
| 18. |
Hideo Mori, Keishiro Takeda, Kazuya Handa, Kil-Ju Moon, Pressure Sensitive Paint for measurement of internal flow, KAIST-Kyushu Univ. Joint Workshop, 2016.09, Nowadays fast-response pressure sensitive paints (PSP) have been developed [1], but there are still very few applications of PSP for measurement of nonstationary pressure distribution of internal flows. Applying PSP on a transparent solid surface (e.g. shroud surface of turbomachinery) made of glass or acrylic resin and taking the luminescent image of PSP through the transparent material results in low S/N, because PSP without opaque white basecoat has low luminescent intensity and overlaying image through the transparent material and translucent PSP layer cause significant error in taking the luminescent image of PSP. To solve the problem, we have developed the fast-response PSP with an opaque, oxygen-permeable overcoat layer having porous structure made of nanoparticles of boron nitride (BN), which enables to increase the S/N of PSP for measurement of internal flows. From the static calibration tests, it is clarified that the opaque overcoat of BN nanoparticle does not reduce the pressure sensitivity of the PSP. From the dynamic calibration tests using an acoustic resonant tube, we also have clarified that the opaque coating of BN nanoparticle does not reduce the time response of the fast-response PSP for pressure fluctuation whose amplitude is of the order of 100Pa, within the frequency range lower than 3kHz.. |
| 19. |
Measurement technique of pressure and temperature by dual-layer PSP/TSP with lifetime based method using high speed camera. |
| 20. |
Development of measurement technique for pressure distribution of inner flow of turbo machinery by using pressure sensitive paint. |
| 21. |
Hideo Mori, Yuki Uchida, Keishiro Takeda, Masashi Yoshikawa, Kazuya Handa, Kil-Ju Moon, Development of PSP for Measurement of Internal Flows, The 17th International Symposium on Flow Visualization, 2016.06, Nowadays fast-response pressure sensitive paints (PSP) have been developed, but there are still very few applications of PSP for measurement of nonstationary pressure distribution of internal flows, because of the very limited optical access of the target system. By applying PSP on a transparent solid surface (e.g. wall of pipes or shrouds of turbomachinery, made of glass or acrylic resin) and taking the luminescent image of PSP through the transparent solid body, pressure distribution on the surface caused by internal flows can be measured in principle. However, low S/N caused by low luminescent intensity of PSP without screen layer and overlaying image through the transparent solid body and translucent PSP layer, acting as one of noise sources, is a serious problem for practical application of PSP. We have developed the fast-response PSP with an opaque overcoat layer having porous structure made of nanoparticles of boron nitride (BN) whose average particle size of 50nm, which enables to increase the S/N of PSP for measurement of internal flows. The pressure sensitivity of the PSP is examined, and it is clarified that the opaque overcoat of BN nanoparticle does not reduce the pressure sensitivity of the PSP. We also have examined the time response of the PSP by using an acoustic resonant tube, to compare the time response of the PSP with BN overcoat with that of the PSP without overcoat. As a result it is clarified that the opaque coating of BN nanoparticle does not reduce the time response of the fast-response PSP for pressure fluctuation whose amplitude is of the order of 100Pa, within the frequency range lower than 3kHz.. |
| 22. |
Kil-Ju Moon, Hideo Mori, Simultaneous Measurement of Pressure and Temperature using Dual-layer PSP/TSP by Lifetime-based Method, The 17th International Symposium on Flow Visualization, 2016.06, The greatest advantage of the lifetime-based method for pressure sensitive paint (PSP) and temperature sensitive paint (TSP) compared with the widely used intensity-based method is that reference images are not required, because theoretically lifetime of PSP luminescence does not depend on luminophore concentration, paint thickness, photodegradation and paint contamination. However, lifetime of PSP luminescence as well as intensity has temperature dependence, and temperature compensation of PSP is needed to increase the accuracy of pressure measurement. To solve this problem, we introduced dual-layer PSP/TSP, the combining method of PSP and TSP. However, simultaneous measurement of pressure and temperature by the intensity-based method needs two cameras because different optical filters are needed to separate the luminescence of PSP and TSP. On the other hand, because luminophores of PSP and TSP has different lifetime, the two luminescence can be separated by using the lifetime difference instead of using different optical filters, allowing simultaneous measurement by dual-layer PSP with one camera. In this study we have clarified the lifetime sensitivity of the dual-layer PSP/TSP in low-gauge pressure conditions in order to show the feasibility of the dual-layer PSP/TSP with the lifetime-based method for the measurement in low-speed flow fields with temperature distribution. Normalized luminescence intensity at 22.5μs after the end of excitation light has high pressure dependence, while the luminescence of TSP has almost vanished at 22.5μs. On the other hand, normalized luminescence intensity at 6.25μs has high temperature sensitivity, while the pressure sensitivity at 6.25μs is very small. Using this combining method, temperature information obtained by the TSP can be used for the temperature compensation of the PSP. . |
| 23. |
Hideo Mori, Kyohei Maeda, Masato Furukawa, Masao Akiyoshi, Measurement technique for unsteady low-speed flow fields using poly(TMSP)-based pressure sensitive paint, ASME-JSME-KSME Joint Fluids Engineering Conference 2015, 2015.07. |
| 24. |
Measurement Technique for Unsteady Low-speed Flow Fields Using Polymer-type Pressure Sensitive Paint
. |
| 25. |
Hideo Mori, Naoto Omura, Kyohei Maeda, Takayuki Ohbuchi, Susumu Nakano, Hideki Ono, Yuta Yanase, Imaging measurement of the pressure distribution using dual-layer PSP/TSP in the supersonic flow field with shockwaves, 16th International Symposium on Flow Visualization, 2014.06, We apply pressure sensitive paint (PSP) to quantitative analysis of pressure distribution and visualization of shockwave structures on a sidewall in a supersonic flow passing through a turbine cascade. To compensate for the temperature dependence of PSP, we apply dual-layer PSP/TSP, the combination method of PSP and temperature sensitive paint (TSP) based on luminescent nanoparticles of ZnS-AgInS2 (ZAIS). Accuracy of the pressure measurement of the sidewall with non-uniform temperature distribution by the dual-layer PSP/TSP is examined in the supersonic wind tunnel tests, by comparing the pressure data obtained by the dual-layer PSP/TSP with those measured by pressure taps. The pressure distribution on the sidewall measured by the PSP component showed large error without temperature compensation, which is reduced effectively by the temperature compensation using the temperature distribution obtained by the TSP component. In addition, the shockwave structures visualized by the dual-layer PSP/TSP is compared with those obtained by the schlieren photograph. There is slight difference in shock angles and thickness between them, because the PSP visualizes the shockwave structure close to the sidewall while the schlieren photograph visualizes the shock structure in the mainstream.. |
| 26. |
Measurement for pressure distribution on blade surfaces of consumer propeller fan using pressure and temperature sensitive paint. |
| 27. |
Visualization of the pressure distribution using dual-layer PSP/TSP in the supersonic flow field. |
| 28. |
Accuracy of Pressure Measurement in Low Speed Flows by Dual-layer PSP/TSP. |
| 29. |
Hideo Mori, Kil-Ju Moon, Yuichiro Ambe, Hiroaki Kawabata, Naoto Omura, Pressure and temperature measurements in low-speed flow field using dual-layer PSP and TSP, The Sixth KAIST-Kyushu University Joint Workshop on Frontiers in Mechanical and Aerospace Engineering, 2012.09, Pressure sensitive paint (PSP) is a powerful measurement tool to visualize pressure distribution on solid surfaces using emission of luminescent molecules, and application of PSP to analysis of complex pressure distribution in several experimental fluid dynamics (EFD) problems is strongly demanded. However, it is difficult to apply PSP to low-speed flow fields with small differential pressure and non-uniform temperature distribution, which may cause a significant error of the pressure measurement. Therefore temperature compensation of PSP is needed to obtain highly precise pressure distribution when PSP is applied to low speed flow field with low gauge pressure. In this study temperature sensitive paint (TSP) is employed for temperature compensation of PSP to increase the accuracy of pressure measurement using PSP in conditions with non-uniform temperature distribution. We have developed dual-layer PSP/TSP by painting PSP over a TSP layer. By using this method, temperature distribution on solid surfaces can be measured by TSP layer, and the temperature distribution map can be used for temperature compensation of PSP. We discuss the sensitivity of the dual-layer PSP/TSP in low gauge pressure conditions below 1kPa, and the effect of the temperature compensation to increase the accuracy of pressure obtained by PSP.. |
| 30. |
Hideo Mori, Naoto Omura, Hiroaki Kawabata, Kil-Ju Moon, Yuichiro Ambe, Combined Method of PSP and TSP for Low-speed Flows, 3rd Japanese-German Joint Seminar, Molecular Imaging Technology for Interdisciplinary Research, , 2012.09. |
| 31. |
Measurement Technique for Rotor Surfaces of Low-pressure Turbomachinery Using Pressure and Temperature Sensitive Paints. |
| 32. |
Pressure measurement methods for blade surfaces of propeller fan using pressure sensitive paint. |
| 33. |
Temperature compensation of PSP component for dual-layer PSP/TSP in low-speed flow. |
| 34. |
Development of Measurement Technique at Low-speed Flow Fields using Pressure Sensitive Paint. |
| 35. |
Experimental Analysis for Sidewall Shape Optimization for Linear Aerospike Nozzle using NO-LIF and PSP. |
| 36. |
Analysis of rotational energy of nitrogen molecular beam by REMPI. |
| 37. |
Sidewall Shape Optimization for Linear Aerospike Nozzle using NO-LIF and PSP. |
| 38. |
Measurement of rotational energy of nitrogen molecular beam by REMPI. |
