Accepted Manuscript Title: A Grid-Pattern PSP/TSP System for Simultaneous Pressure and Temperature Measurements Author: Di Peng Yingzheng Liu PII: DOI: Reference:
S0925-4005(15)30248-3 http://dx.doi.org/doi:10.1016/j.snb.2015.08.070 SNB 18925
To appear in:
Sensors and Actuators B
Received date: Revised date: Accepted date:
31-5-2015 11-8-2015 15-8-2015
Please cite this article as: D. Peng, Y. Liu, A Grid-Pattern PSP/TSP System for Simultaneous Pressure and Temperature Measurements, Sensors and Actuators B: Chemical (2015), http://dx.doi.org/10.1016/j.snb.2015.08.070 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A Grid-Pattern PSP/TSP System for Simultaneous Pressure and Temperature Measurements Di Penga,b, Yingzheng Liua,b* Key Lab of Education Ministry for Power Machinery and Engineering, School of Mechanical
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a
Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China b
Gas Turbine Research Institute, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai
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200240, China.
A novel combined pressure- and temperature-sensitive paint system has been developed for simultaneous pressure and temperature measurements using a monochrome camera. This grid-pattern PSP/TSP system consists of an array
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of PSP dots (PtTFPP in polymer-ceramic binder) on top of a TSP layer (Ru(dpp) in clearcoat). The physical separation of PSP and TSP eliminates problems involving chemical interactions and spectral interference which are commonly seen in dual-luminophore PSPs. Both PSP and TSP are excited by a 400nm LED and the signals are
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captured simultaneously by a monochrome charged-couple device (CCD) camera. The key challenge is to precisely identify PSP and TSP regions from the grid pattern in each image. This has been realized by first creating a sharp environmental change in temperature or oxygen concentration, and then separating PSP region from TSP region
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based on the difference in intensity-ratio caused by paint properties. Full pressure and temperature fields are
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recovered by performing 2-D interpolation on PSP and TSP data, and the temperature field is then used to remove the temperature-induced errors in PSP results. This PSP/TSP system has been demonstrated in oblique jet
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impingement experiments.
1. Introduction
Surface pressure and temperature fields with high spatial resolution are desired in many scenarios of aerodynamic research. For example, the pressure loads and heat fluxes are both critical parameters in studies of jet impingement, turbomachinery and reentry objects. Simultaneous pressure and temperature measurements can be achieved by integrating pressure- and temperature-sensitive paints to form a two-component PSP/TSP system. A further benefit of such a paint system is that the temperature-induced errors in PSP can be readily removed based on the measured temperature field. Typically, a combined PSP/TSP system is developed by mixing two or more different luminophores into the same binder to form a multi-luminophore paint which usually contains a PSP channel and a TSP channel, as shown in Fig. 1(a). The PSP and TSP channels generally have similar absorption spectrum but with separated emission spectrum, and the signals are captured by either a camera with a filter-wheel system or a color camera. A number of
*Corresponding author. Email:
[email protected]
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formulations of multi-luminophore paint have been developed primarily for the purpose of compensating temperature-induced errors in PSP, as being reviewed in ref.[1]. More recently, a three-component paint system was developed by Fischer et al. including a pressure channel, a temperature channel and a reference channel [2]. The
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paint was designed such that the emission signals from the three channels fell within the Red/Green/Blue channels of a color camera, respectively. However, a major issue of multi-luminophore paint is that many sensors display rather broad emission band which leads to certain level of spectral interference between the PSP and TSP channels,
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even if the emission peaks are already well separated [3]. The spectral interference reduces the pressure sensitivity
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of PSP channel and also induces unwanted pressure sensitivity in TSP channel. Moreover, the interactions between luminophores within the binder, including energy transfer and spectral cross-talk, are commonly seen in multi-
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luminophore paint, which in some cases result in degradations in signal level, photo-stability and lifetime [4, 5].
Fig. 1 Three types of combined PSP/TSP system: (a) multi-luminophore paint, (b) multi-layer paint and (c) dualsensor arrays.
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An alternative configuration of a combined PSP/TSP system is multi-layer paint, in which the pressure and temperature sensors are physically separated and confined in its own binder, as shown in Fig. 1(b). The TSP layer with oxygen-impermeable binder lies on the bottom, while the PSP layer is on top to facilitate its interaction with oxygen. In some cases, an extra layer is inserted between the PSP and TSP layer to prevent mixing and energy transfer [6, 7]. Spectral separation is required for the emission signals from PSP and TSP layers, and the data acquisition system is also similar to the case of multi-luminophore paint. This configuration eliminates most interactions between luminophores, and allows some luminophores with cross-sensitivity (sensitive to both pressure and temperature) to be used as temperature sensor. But the issue of spectral interference still exists. Another concern is that the signal level of TSP layer can be attenuated significantly if the PSP layer is not entirely transparent [8]. The third way to create a combined PSP/TSP system is through dual-sensor arrays, in which PSP and TSP dots are placed alternatively in close proximity, as shown in Fig. 1(c). This configuration is immune to both luminophore interaction and spectral interference at the cost of spatial resolution. The preparation of sensor arrays is generally
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more challenging than multi-luminophore paint and multi-layer paint. Kamaya et al. used inkjet-printing to fabricate dual-sensor arrays on a thin layer chromatography (TLC) plate with 0.3mm dot diameter and 0.6 mm interval [5]. A camera equipped with a stereo-viewer was used to capture PSP and TSP signals simultaneously, which was placed
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far enough from the painted surface so that each dot was obscured and the gaps between dots were not visible. More recently, a fast-responding bi-luminophore PSP was created by applying inkjet-printing on anodized aluminum substrate, which had a frequency response less than 20 µs [9].
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In the current study, a novel grid-pattern PSP/TSP system has been developed which consists of a TSP layer on
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the bottom and fast PSP sensor arrays on top, as shown in Fig. 2. The PSP and TSP sensors are physically separated to prevent luminophore interaction, and the PSP binder is non-transparent so that the TSP signal will not be
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interfering with the PSP signal. More importantly, the data acquisition device for this grid-pattern PSP/TSP system is as simple as a monochrome camera with a single long-pass filter. Image-processing algorithms have been developed to identify PSP and TSP regions based on intensity ratios and reconstruct the full pressure and
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temperature field through interpolation. The fabrication method, paint properties, data processing schemes and the applications of jet impingement tests will be described in detail through the rest of this paper. The potential use of
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this paint system for unsteady pressure and temperature measurements on rotating surfaces will also be discussed.
Fig. 2 Schematic of the grid-pattern PSP/TSP system.
2. Grid-Pattern PSP/TSP System 2.1 Materials and Fabrication Method
In the current paint system, the TSP layer uses an oxygen-impermeable automobile clearcoat (Dupont ChromClear HC7776S) as binder and Ru(dpp) (from GFS Chemicals, Inc.) as temperature sensor, while PSP uses a polymer-ceramic (PC) binder (initially developed by Gregory et al. [10]) and PtTFPP (from Frontier Scientific) as
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pressure sensor. The PC binder is basically a mixture of high concentration of ceramic particles with a small amount of polymer to physically hold the ceramic particles to the surface. As shown in Fig. 3, the luminophores are attached onto the porous surface of the binder, which can interact immediately with oxygen, resulting in high frequency
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response (≥6kHz [11]).
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Fig. 3 Schematic illustration (a) and scanning electron micrographs (b) of PC-PSP.[11]
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The current paint system was fabricated through the following steps: 1. The TSP sensor was dissolved in methanol, mixed with clearcoat binder, and then air-sprayed onto the model surface; 2. The TSP layer was dried for
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8-12 hours; 3. The TSP was then covered with a thin perforated polypropylene sheet (with 0.5 mm thickness and 1 mm diameter holes), epoxy glue was applied near the model edges to keep the sheet attached on the surface; 4. PC-
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PSP binder was air-sprayed over the perforated sheet to generate PSP sensor arrays on top of the TSP layer; 5. The
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PSP layer was dried for 3-4 hours; 6. The pressure sensor (PtTFPP) was dissolved in methanol and air-sprayed on PC binder; 7. Finally the perforated sheet was peeled off by hand after a drying time of 0.5 hr. The resulting grid pattern with dimensions is shown in Fig. 4.
Fig. 4 Grid pattern of the combined PSP/TSP system.
2.2 Properties of the paint system The emission spectrum of PSP and TSP sensors (separate samples) was recorded by a spectrometer (USB2000, Ocean Optics) with 400nm LED excitation (ISSI LM2X-DM) at room pressure and temperature, and the results are
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presented in Fig. 5(a), showing significant overlap between them. This will be a serious problem for a multiluminophore paint. However, as mentioned earlier, the current PSP/TSP system does not require spectral separation. The sensor selection can be as free as possible with the removal of the most critical constraint. Fig. 5(b) compares
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the spectrum of the two-color paint (reported in ref. [1]) and its two components. Besides the problem of spectral interference, a valley is observed around 540nm in the spectrum of two-color paint. This is due to luminophore interaction, since PtTFPP has an absorption peak at 540nm and it absorbs some of the emission from the reference
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dyes. Similar behavior was observed by Kameda et al. during the development of dual-sensor array [5]. Again, the
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current PSP/TSP system does not have such issues due to the physical separation between PSP and TSP. 1 PtTFPP Ru(dpp) 0.8
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Fig. 5 Emission spectrum of (a) PtTFPP and Ru(dpp), (b) 2-color paint and its components [1].
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Pressure and temperature calibrations of the current PSP/TSP system were performed in a custom-built calibration chamber with a pressure range from 0 to 345 kPa and a temperature range from 273 to 323 K. A 5mm square paint sample was excited by 400nm LED array and the signal was recorded by a CCD camera (Imperx IPX11M5-L) with a 515nm long-pass filter. Data were averaged within PSP region and TSP region, respectively. The PSP and TSP regions were identified using a temperature difference method, which will be discussed later in this paper. The reference pressure and temperature were 103 kPa and 315 K, respectively, and the calibration curves were forced to pass through (1, 1). The calibration results are presented in Fig. 6, showing that the TSP has very little pressure sensitivity as expected. The PSP displays significant temperature sensitivity, but the temperatureinduced errors can be removed using the TSP data, as discussed in Section 3.3.
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1.8
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Fig. 6 Pressure (a) and Temperature (b) calibration results of the grid-pattern PSP/TSP system. Surface profile measurements were also performed using a 3D optical surface profiler (ZeGageTM) with a
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spatial resolution of 2.45 µm over an area of 8mm × 8mm on the paint sample. The purpose was to evaluate the possible interference between PSP and TSP signals in PSP region. Fig. 7(a) presents the averaged profile of 20 PSP
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dots, while Fig. 7(b) shows the line profile taken horizontally through the center of the dot. Based on the surface profile data, the PSP thickness was around 20 µm. The signal attenuation effect due to PC-PSP top layer in a two-
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layer paint system was studied in ref. [8], showing that the relation between the overall attenuation of TSP signal (µ)
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and PC-binder thickness (h) can be described as:
µ = 1 - A ⋅ e − Bh
(1)
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where A = 0.934 and B = 0.261 are constants. Therefore, the amount of TSP signal attenuation can be estimated based on line profile data, as shown in Fig. 8. The attenuation was generally over 98% in PSP region (-0.5mm < x < 0.5mm), proving that the spectral interference between PSP and TSP signals was negligible in PSP region. However, this was not true for the intermediate region between TSP and PSP, where the PSP layer was thin. Data in this region should be excluded as discussed later in Section 3.1. It should be noted that the wavelength range of the bottom layer signal in ref. [8] (500-600 nm) was slightly lower than the TSP signal of the current paint system (550-650 nm), therefore the analysis based on Eq. (1) needs to be further validated. For that purpose, pressure and temperature calibrations were performed for PC-PSP without TSP bottom layer, and the pressure and temperature sensitivity was found to be 0.7%/kPa and 2.4%/K, respectively. The above values are very close to those obtained from Fig. 6, which are 0.68%/kPa and 2.3%/K. This proves that the effect of spectral interference is minimal within the PSP region of the current PSP/TSP system.
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m m y,
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Fig. 7 Averaged (a) surface profile and (b) line profile of PSP dot.
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Fig. 8 Overall attenuation of TSP signal in PSP region.
2.3 Experiment Setup for Paint Demonstration The grid-pattern PSP/TSP system was demonstrated through two jet impingement experiments: a small oxygen-free jet and a high-speed air jet. The test setups are shown in Fig. 9. A 100 by 100 mm flat metal plate covered with the combine PSP/TSP system was placed on top of a thermostat (Fanyuhang, SET-1515) with thermal grease between them. The light source and camera were the same as those used for calibration. During the oxygenfree jet experiment, a dust remover which contains HCFC (hydrochlorofluorocarbon) was used to generate oxygenfree jet which impinges obliquely onto the surface at room temperature (297K). The case was mainly for demonstrating the data processing procedures. For the high-speed jet experiment, a 5.6 mm diameter nozzle was connected to a high pressure air tank and the jet was impinging on the surface at α = 30°, H/D = 6 and T = 306K. In both cases, the reference images were taken before the jet was turned on. This case provided quantitative results to evaluate the accuracy of pressure and temperature measurements, as well as the fidelity of temperature correction.
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Fig. 9 Experimental setups of (a) oxygen-free jet impingement and (b) high-speed jet impingement.
3. Data Processing Methods
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3.1 Identification of PSP and TSP Regions
To measure pressure and temperature simultaneously with one monochrome camera, it is necessary to
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accurately identify PSP and TSP regions from the grid pattern. This can be achieved by creating an environment that causes a clear difference in PSP and TSP signals. Two methods are currently available for this purpose: oxygen-
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difference method and temperature-difference method. In oxygen-difference method, an image is taken with the
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LED on as an oxygen-free jet is blowing over the painted surface, and then a reference image is taken right after the jet is shut off. Due to the large difference in pressure sensitivity (see Fig. 6(a)), the PSP and TSP regions can be
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clearly separated by the intensity ratio between the jet-on image and the reference image. In temperature-difference method, the painted model is placed in/on a temperature control unit, and two images are taken with the LED on at different temperatures. Due to the clear difference in temperature sensitivity (see Fig. 6(b)), the PSP and TSP regions can be separated by the intensity ratio between the two images at different temperatures. The steps of PSP/TSP region identification using temperature-difference method is described below. The two temperatures set by the thermostat were T1 = 297K and T2 = 310K, and the intensity ratio (IT2 / IT1) data is shown on the left of Fig. 10. According to the calibration results, the intensity ratio of PSP and TSP should be around 0.68 and 0.82, respectively, which were obtained using Eq. (2). Here Iref / I at T1 and T2 were directly found from the temperature calibration curves in Fig. 6(b). The average value (0.75) was used as the threshold to separate PSP and TSP regions, and the results are shown on the right in Fig. 10. However, a closer look at the initially identified regions revealed that the edges (intermediate region between PSP and TSP) of the PSP and TSP regions had different levels of intensity ratios than the rest, as shown in Fig. 11. This was because the PC-PSP binder was too
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thin to completely block the TSP signal at the edges (see Fig. 7(b)). Both PSP and TSP signals were present so the resulting intensity ratio was between 0.7 and 0.8. It was difficult to remove those pixels without losing some pixels well within the PSP/TSP region by simply specifying thresholds of intensity ratio. Therefore, an iterative algorithm
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was developed to remove the edges of PSP and TSP regions. The standard deviation of all remaining pixels was calculated after each iteration, and the iteration stopped when the standard deviation after the current iteration was no less than the previous one. It usually took 3-4 iterations to completely remove the edges with erroneous intensity
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ratios. The final PSP and TSP regions after applying 4 iterations are presented in Fig. 12, which were then used to extract PSP and TSP data from the ratio of jet-on and jet-off images.
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Fig. 10 Initial identification of PSP and TSP regions using temperature-difference method. 0.75 5
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Fig. 11 Different levels of intensity ratio at the edges of (a) PSP and (b) TSP regions.
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3.2 Reconstruction of Pressure and Temperature Fields
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Fig. 12 Identified (a) PSP and (b) TSP regions after edge-removal.
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The PSP and TSP data extracted from the raw intensity ratio (Iref /I) were discontinuous in the two-dimensional surface, but there were still sufficient data to perform 2D-interpolation to reconstruct the full pressure and
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temperature fields. The data of PSP and TSP region were first filtered slightly using a 5 by 5 pixel (0.3 × 0.3 mm) average filter, and then the full field PSP and TSP data were recovered using “griddata” function in Matlab with the
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interpolation type set to “natural” (natural neighboring interpolation). This method of spatial interpolation was
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developed by Sibson [12], which provides a smoother approximation to the “true” function than other method such as linear interpolation and nearest neighboring interpolation. Again, spatial filtering was performed on the full field
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data with a size of 10-pixel (0.6 mm) for PSP and 20-pixel (1.2 mm) for TSP.
3.3 Correction of Temperature-Induced Errors Once the full field PSP and TSP data were obtained, the temperature correction could be carried out on PSP data using the following equation:
I ref I
=
I PSP _ ref ITSP _ ref I TSP
I PSP − 1 × k (T ) + 1
(3)
where k was the ratio of temperature sensitivity determined by the calibration results in Fig. 6(b). This correction method was first suggested by Peng et al. [1]. Please note that k was a function of temperature due to the nonlinearity of the calibration curves, as shown in Fig. 13. Therefore, the temperature correction must be performed pixel by pixel based on the spatial variation of k in a non-uniform temperature field, as clearly seen in Fig. 14 for the oxygen-free jet case.
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Fig. 13 Temperature dependence of the sensitivity ratio. 15
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4. Results and Discussion
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Fig. 14 Spatial variation of k in non-uniform temperature field.
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4.1 Results of nitrogen jet impingement experiment Fig. 15 presents the data processing steps of the oxygen-free jet case. The PSP results showed that the oxygen concentration was low near the center of the jet, and the temperature also decreased near the center of the jet due to the cooling effect. In general, the full pressure and temperature fields can be obtained based on the calibration data, but in this case the pressure field was not available since PSP data was indicating oxygen concentration rather than pressure.
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Fig. 15 Data processing procedures of the oxygen-free jet experiment.
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4.2 Results of high-speed jet impingement experiment
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The results of high-speed jet impingement experiment are presented in this section. Fig. 16 shows the
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temperature field measured by TSP of the grid paint system with the jet coming from the left. In general the surface was cooled down by the jet, and there was a low temperature region around the impingement location where the temperature was approximately 3K lower than the edge of the impingement area. As a result, the pressure field obtained from PSP data (Fig. 17(a)) showed unrealistic low pressure across the surface. Such a large temperature– induced error could be reduced by applying an in-situ shift based on the ambient pressure as suggested in ref. [13], but still the error due to non-uniform temperature field could not be removed without the knowledge of the exact temperature field. The sensitivity-ratio based correction scheme previously discussed was able to remove the error, and the resulting pressure field was reasonable as shown in Fig. 17(b), where the jet caused a high pressure region near the impingement point and the pressure in the surrounding area was close to ambient pressure (101.7 kPa). Fig. 18 compares the pressure distributions along the jet centerline before and after the correction (using both in-situ shift method and sensitivity-ratio method), where the flat dashed line shows the ambient pressure. Here the in-situ shift was performed with the assumption that the pressure at x/D = 0 was not affected by the jet and the pressure was
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essentially the ambient pressure. It was clear that the in-situ shift method (or in-situ calibration if pressure taps were available) was insufficient to remove the temperature-induced errors. To make accurate PSP measurements on surface with non-uniform temperature, it is necessary to simultaneously measure temperature and perform
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corrections accordingly. The jet impingement data in current study is also compared with data acquired at similar condition (α = 30°, H/D = 6, P0/P∞ = 1.41) by Crafton [14], and the overall agreement is good according to Fig. 19. This proves that the current paint system and correction method are able to remove the temperature-induced errors
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and provide pressure data with good accuracy.
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Fig. 16 Temperature field on the flat plate during jet impingement. 90
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Fig. 18 Pressure distributions along the center before/after correction.
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Fig. 19 Comparison between data in current study and data from Crafton [14].
4.3 Discussion of the current paint formulation and measurement technique The following two requirements should be met for any successful application of the current paint system: 1. the spatial resolution of the PSP dots should be small compared to the scales of the pressure features presented in the flow field being measured; 2. the pixel resolution of the imager should be fine enough to guarantee that at least a few pixels are well within each PSP dot and not affected by the edge effects. In the current study, the size of high pressure region on the plate caused by the jet was approximately 25 × 17 mm (4D × 3D) according to Fig. 17. The spatial resolution of the PSP dots was 1.4mm (0.25D) based on the schematic shown in Fig. 4, and the pixel resolution of the camera was 0.06mm (< 5% of the PSP dot diameter). Therefore, the resolution of PSP dots and the camera was sufficient to resolve the pressure field in the current jet impingement case. However, if the jet velocity is increased to sonic and beyond, it is very likely the resolution of PSP dots is not enough to resolve the shocks and
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expansion waves appear on the plate. For cases with small scale pressure features, it is necessary to increase the spatial resolution of PSP dots by using a perforated plate with smaller but denser holes during painting. The minimum dot size and spacing achieved using the current painting method were 0.5 mm and 1 mm, respectively.
plate if the holes are too small, but this limit was not investigated in the current study.
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There should be a lower limit for PSP dot size because it will be difficult for the paint to get through the perforated
The surface roughness obtained from the surface profile data for an 8mm × 8mm area was 7.3 µm, which was
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higher than the typical roughness of PC-PSP (around 3 µm according to Pandey and Gregory [15]). The increased
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roughness was mainly due to the thickness of PSP dots. As discussed by Liu and Sullivan [16], the paint roughness may alter the flows over the model and also affect pressure, skin friction and the integrated aerodynamic forces. In
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some cases, the paint roughness can lead to early transition or separation. Since the effect of painting roughness highly depends on the flow over a specific model configuration, it is necessary to evaluate this effect during applications of the current paint system. Meanwhile, the authors are looking into the possibilities to create a smooth
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grid PSP/TSP system using a high-precision air painting system with two nozzles.
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4.4 Potential Applications to Unsteady Measurements on Rotating Surfaces The PSP and TSP in the current paint system were previously applied in unsteady pressure measurements on
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model helicopter blades using a single-shot lifetime-based technique [13]. The PSP and TSP were painted on
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separate blades, and pressure and temperature measurements were made separately after the thermostatic condition was reached. A pulsed laser was used for illumination, and a double-exposure CCD camera was used to take two consecutive images on the luminescent decay of the paint following the laser pulse, as shown in Fig. 20. The ratio of the integrated signal from the two gates was computed and calibrated to provide the pressure and temperature fields. The lifetimes of PSP (~10 µs) and TSP (~5 µs) were short enough for unsteady measurements, and also long enough for applying the two-gate method within the capability of the double-exposure camera. Therefore, the current PSP/TSP system can be readily implemented to simultaneous pressure and temperature measurements on rotating surfaces using the single-shot lifetime-based technique.
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Fig. 20 Data acquisition of single-shot lifetime-based method. [13]
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A further potential application of the grid-pattern PSP/TSP system is blade deformation measurement. It has been shown by Liu et al. [17] that the PSP images with markers can serve as inputs in videogrammetric model
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deformation technique (VMD) to obtain the displacement of each marker point and eventually reconstruct the deformation field of the entire surface. Here, the PSP sensor arrays can be readily used as markers, and such high-
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density marker arrays (see Fig. 4) will significantly improve the resolution and accuracy of deformation measurements. It is feasible to achieve simultaneous measurements of pressure, temperature and deformation of
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5. Conclusions
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rotating blades with the current paint system and two CCD cameras.
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A grid-pattern PSP/TSP system has been developed for simultaneous pressure and temperature measurements with temperature-correction capability. This paint system avoids the common issues of multi-luminophore paints, such as chemical interaction and spectral interference, through the physical separation of PSP and TSP. It also simplifies the data acquisition system to a monochrome camera thanks to a set of data processing techniques, especially the PSP/TSP region identification method (with edge-removal). The fast-responding feature of PC-PSP and the lifetime characteristics of both PSP and TSP indicate that this paint system has great potential in unsteady measurement for rotating surfaces, and this will be the focus of future work.
Acknowledgements The authors would like to thank Ph.D student Tao Cai for his assistance in surface profile measurements and experimental setups. This work was supported by funding from Gas Turbine Research Institute of Shanghai Jiao Tong University.
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References
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[1] Peng, D., Jensen, C.D., Juliano, T.J., Gregory, J.W., Crafton, J., Palluconi, S., and Liu, T., "TemperatureCompensated Fast Pressure-Sensitive Paint," AIAA Journal, Vol. 51, No. 10, 2013, pp. 2420-2431. doi: 10.2514/1.J052318. [2] Fischer, L.H., Karakus, C., Meier, R.J., Risch, N., Wolfbeis, O.S., Holder, E., and Schaferling, M., "Referenced Dual Pressure- and Temperature-Sensitive Paint for Digital Color Camera Read Out," Chemistry-A European Journal, Vol. 18, No. 49, 2012, pp. 15706-15713. doi: 10.1002/chem.201201358. [3] Stich, M.I., Fischer, L.H., and Wolfbeis, O.S., "Multiple fluorescent chemical sensing and imaging," Chemical Society Reviews, Vol. 39, 2010, pp. 3102-3114. doi: 10.1039/b909635n. [4] Nagl, S., and Wolfbeis, O.S., "Optical multiple chemical sensing: status and current challenges," Analyst, Vol. 132, 2007, pp. 507-511. doi: 10.1039/b702753b. [5] Kameya, T., Matsuda, Y., Egami, Y., Yamaguchi, H., and Niimi, T., "Dual luminescent arrays sensor fabricated by inkjet-printing of pressure- and temperature-sensitive paints," Sensors and Actuators B: Chemical, Vol. 190, 2014, pp. 70-77. doi: 10.1016/j.snb.2013.08.011. [6] Hyakutake, T., Taguchi, H., Kato, J., Nishide, H., and Watanabe, M., "Luminescent Multi-Layered Polymer Coating for the Simultaneous Detection of Oxygen Pressure and Temperature," Macromolecular Chemistry and Physics, Vol. 210, 2009, pp. 1230-1234. doi: 10.1002/macp.200900176. [7] Moon, K., Mori, H., Ambe, Y., and Kawabata, H., "Development of Dual-Layer PSP/TSP System for Pressure and Temperature Measurement in Low-Speed Flow Field," Proceedings of the ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011-11020, ASME, Hamamatsu, Japan, 2012. [8] Peng, D., Gregory, J.W., Crafton, J., and Fonov, S., "Development of a Two Layer Dual-Luminophore Pressure Sensitive Paint for Unsteady Pressure Measurements," 27th AIAA Aerodynamic Measurement Technology and Ground Testing Conference, AIAA 2010-4918, American Institute of Aeronautics and Astronautics, 2010. [9] Egami, Y., Ueyama, J., Furukawa, S., Kameya, T., Matsuda, Y., Yamaguchi, H., and Niimi, T., "Development of fast response bi-luminophore pressure-sensitive paint by means of an inkjet printing technique," Measurement Science and Tecnology, Vol. 26, No. 6, 2015, pp. 064004 1-8. doi:10.1088/0957-0233/26/6/064004 [10] Gregory, J.W., Asai, K., Kameda, M., Liu, T., and Sullivan, J.P., "A Review of Pressure-Sensitive Paint for High-Speed and Unsteady Aerodynamics," Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, Vol. 222, No. 2, 2008, pp. 249-290. doi: 10.1243/09544100JAERO243. [11] Gregory, J.W., Sakaue, H., Liu, T., and Sullivan, J.P., "Fast Pressure-Sensitive Paint for Flow and Acoustic Diagnostics," Annual Review of Fluid Mechanics, Vol. 56, 2014, pp. 303-330. doi: 10.1146/annurev-fluid010313-141304. [12] Sibson, R. "A brief description of natural neighbor interpolation (Chapter 2)". In V. Barnett. Interpreting Multivariate Data. Chichester: John Wiley, 1981. pp. 21–36. [13] Disotell, K.J., Peng, D., Juliano, T.J., Gregory, J.W., Crafton, J.W., and Komerath, N.M., "Single-shot temperature- and pressure-sensitive paint measurements on an unsteady helicopter blade," Experiments in Fluids, Vol. 55, No. 2, 2014, pp. 1671. doi: 10.1007/s00348-014-1671-2. [14] Crafton, J.W., "The Impingement of Sonic and Sub-Sonic Jets onto a Flat Plate at Inclined Angles," Ph.D. Dissertation, Purdue University, 2004. [15] Pandey, A. and Gregory, J.W., "Dynamic Response Characteristics of Polymer/Ceramic PressureSensitive Paint," 53rd AIAA Aerospace Sciences Meeting, AIAA 2015-0021, American Institute of Aeronautics and Astronautics, 2015. [16] Liu, T., and Sullivan, J. P., Pressure and Temperature Sensitive Paints, Springer, New York, 2005, pp.147-148. [17] Liu, T., Montefort, J., Gregory, J.W., Palluconi, S., Crafton, J., and Fonov, S., "Wing Deformation Measurements from Pressure Sensitive Paint Images Using Videogrammetry," AIAA 2011-3725, Honolulu, Hawaii, 2011.
Biographies
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Di Peng received his Ph.D in aerospace engineering from The Ohio State University in 2014. He is currently an assistant professor in School of Mechanical Engineering, Shanghai Jiao Tong University. His main research interest is pressure- and temperature- sensitive paints and their
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applications in aerodynamic testing.
Yingzheng Liu received his Ph.D in mechanical engineering from Shanghai Jiao Tong
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University in 2000. He is currently a professor in School of Mechanical Engineering, Shanghai Jiao Tong University. He also serves as vice dean for Gas Turbine Research Institute at SJTU.
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His research interest includes advanced measurement technologies of fluid mechanics (PDPA, PIV, LIF, PSV, PSP), turbulent flow and flow control, complex flow and heat transfer in
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turbomachinery, as well as bio-fluid mechanics.
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