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Pressure-sensitive paint measurements of transient shock phenomena.

Quinn MK, Kontis K - Sensors (Basel) (2013)

Bottom Line: Illumination comes from two high-intensity broadband Xenon arc light sources with short-pass filters.The sample is imaged at 100 kHz using a Vision Research Phantom V710 in conjunction with a pair of long and short pass filters, creating a band.The PSP results are compared with numerical simulations of the flow using the commercial CFD package Fluent as part of ANSYS 13 for two Mach numbers.

View Article: PubMed Central - PubMed

Affiliation: Aero-Physics Laboratory, University of Manchester, Manchester, UK. mark.quinn-2@postgrad.manchester.ac.uk

ABSTRACT
Measurements of the global pressure field created by shock wave diffraction have been captured optically using a porous pressure-sensitive paint. The pressure field created by a diffracting shock wave shows large increases and decreases in pressure and can be reasonably accurately captured using CFD. The substrate, a thin-layer chromatography (TLC) plate, has been dipped in a luminophore solution. TLC plates are readily available and easy to prepare. Illumination comes from two high-intensity broadband Xenon arc light sources with short-pass filters. The sample is imaged at 100 kHz using a Vision Research Phantom V710 in conjunction with a pair of long and short pass filters, creating a band. The PSP results are compared with numerical simulations of the flow using the commercial CFD package Fluent as part of ANSYS 13 for two Mach numbers.

No MeSH data available.


Related in: MedlinePlus

PSP map of Mi = 1.28 shock diffraction process. (a) 20 μs; (b) 40 μs; (c) 60 μs; (d) 80 μs; (e) 100 μs; (f) 120 μs; (g) 140 μs; (h) 160 μs; (i) 180 μs; (j) 200 μs; (k) 220 μs; (l) 240 μs.
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f10-sensors-13-04404: PSP map of Mi = 1.28 shock diffraction process. (a) 20 μs; (b) 40 μs; (c) 60 μs; (d) 80 μs; (e) 100 μs; (f) 120 μs; (g) 140 μs; (h) 160 μs; (i) 180 μs; (j) 200 μs; (k) 220 μs; (l) 240 μs.

Mentions: Figure 10(a) shows the incident shock wave and the pressure rise behind it. There is a significant degree of spatial noise despite taking an ensemble average of three individual tests and using a 3 × 3 linear filter to process the results. The pressure rise of 1.68 bar correlates well with the expected value of 1.75 bar given by inviscid theory based on Mie. Figure 10(b) begins to show the vortex shed from the apex. Subsequent, Figure 10(c) and onwards show the pressure drop in the centre of the vortex to its lowest value of 0.46 bar. The vortex remains approximately the same size from Figure 10(f) onwards. In the same images, the reflected expansion wave can be seen to be propagating upstream and downwards from the apex, as the pressure in this region is reduced compared with the region of uniform high pressure at the inlet to the test section. The pressure above the splitter does not change significantly over the first few images, indicating that the diffracted shock wave in this region is extremely weak.


Pressure-sensitive paint measurements of transient shock phenomena.

Quinn MK, Kontis K - Sensors (Basel) (2013)

PSP map of Mi = 1.28 shock diffraction process. (a) 20 μs; (b) 40 μs; (c) 60 μs; (d) 80 μs; (e) 100 μs; (f) 120 μs; (g) 140 μs; (h) 160 μs; (i) 180 μs; (j) 200 μs; (k) 220 μs; (l) 240 μs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3673091&req=5

f10-sensors-13-04404: PSP map of Mi = 1.28 shock diffraction process. (a) 20 μs; (b) 40 μs; (c) 60 μs; (d) 80 μs; (e) 100 μs; (f) 120 μs; (g) 140 μs; (h) 160 μs; (i) 180 μs; (j) 200 μs; (k) 220 μs; (l) 240 μs.
Mentions: Figure 10(a) shows the incident shock wave and the pressure rise behind it. There is a significant degree of spatial noise despite taking an ensemble average of three individual tests and using a 3 × 3 linear filter to process the results. The pressure rise of 1.68 bar correlates well with the expected value of 1.75 bar given by inviscid theory based on Mie. Figure 10(b) begins to show the vortex shed from the apex. Subsequent, Figure 10(c) and onwards show the pressure drop in the centre of the vortex to its lowest value of 0.46 bar. The vortex remains approximately the same size from Figure 10(f) onwards. In the same images, the reflected expansion wave can be seen to be propagating upstream and downwards from the apex, as the pressure in this region is reduced compared with the region of uniform high pressure at the inlet to the test section. The pressure above the splitter does not change significantly over the first few images, indicating that the diffracted shock wave in this region is extremely weak.

Bottom Line: Illumination comes from two high-intensity broadband Xenon arc light sources with short-pass filters.The sample is imaged at 100 kHz using a Vision Research Phantom V710 in conjunction with a pair of long and short pass filters, creating a band.The PSP results are compared with numerical simulations of the flow using the commercial CFD package Fluent as part of ANSYS 13 for two Mach numbers.

View Article: PubMed Central - PubMed

Affiliation: Aero-Physics Laboratory, University of Manchester, Manchester, UK. mark.quinn-2@postgrad.manchester.ac.uk

ABSTRACT
Measurements of the global pressure field created by shock wave diffraction have been captured optically using a porous pressure-sensitive paint. The pressure field created by a diffracting shock wave shows large increases and decreases in pressure and can be reasonably accurately captured using CFD. The substrate, a thin-layer chromatography (TLC) plate, has been dipped in a luminophore solution. TLC plates are readily available and easy to prepare. Illumination comes from two high-intensity broadband Xenon arc light sources with short-pass filters. The sample is imaged at 100 kHz using a Vision Research Phantom V710 in conjunction with a pair of long and short pass filters, creating a band. The PSP results are compared with numerical simulations of the flow using the commercial CFD package Fluent as part of ANSYS 13 for two Mach numbers.

No MeSH data available.


Related in: MedlinePlus