When using pressure sensitive paint under unsteady conditions in low-speed applications, the signal-to-noise ratio is usually low and may hinder proper evaluation of acquired data. Here, we propose a new noise-filtering scheme that based on singular value decomposition. As test case, evaluate fluctuating field due to vortex shedding side square cylinder. The proposed resulted reduction pixel noise order two magnitudes which made it possible obtain results regarding spatial form flow...

The laminar-to-turbulent boundary-layer transition on a high-speed rotating propeller was measured using Temperature-Sensitive Paint (TSP). TSP formulation, the experimental set-up, image acquisition, and processing procedure had been evaluated in pretest. High resolution images were obtained even at rotation speeds of 9600 rpm. Obtained temperature clearly show steps due to boundary layer transition. Based pretest results, wind tunnel experiment conducted low-speed wind-tunnel BLSWT AIRBUS...

This collaborative work discusses the results of time-resolved pressure-sensitive paint measurements performed on a model generic spacecraft under sub- and transonic test conditions. It is shown that optical pressure using an active layer from platinum–porphyrin complexes (PtTFPP) in combination with polymer-ceramic base are able to measure dynamic flow phenomena trisonic wind tunnel facility up sampling rates 2 kHz. Low amplitude fluctuations order 0.1 kPa were determined by means this...

Recent activities on PSP applications to unsteady low-speed flow at Tohoku University are reported. One significant achievement is the determination of frequency response using an acoustic resonance tube. This apparatus can produce sinusoidal pressure variations in range from 0.1 10 kHz. The amplitude and phase delay characteristics Polymer-Ceramic were measured it was found that PC-PSP had time least 3.8 For measurements, two new types image processing techniques have been developed; one...

The aerodynamics of transport aircraft at the borders flight envelope is characterized by complex interactions and nonlinear, unsteady flow phenomena. underlying physical mechanisms are not fully understood, a prediction aerodynamic properties, transient loads, aeroelastic behavior major challenge that requires use sophisticated numerical models dedicated experiments. A new research initiative investigates three-dimensional buffet high-speed stall, interaction wing wake with empennage,...

Abstract A first time-resolved pressure-sensitive paint (PSP) test campaign at the European Transonic Wind Tunnel (ETW) was conducted within research initiative “Unsteady flow and interaction phenomena High Speed Stall conditions”. One of objectives this wind tunnel to resolve time-series surface pressure distributions caused by complex 3-D buffet on a full-span airplane model XRF-1 transport aircraft configuration. At higher angle-of-attack high Mach number, fluctuations with frequency...

To understand unsteady flow phenomena, it is important to measure time-resolved pressure variations with high spatial resolution. Pressure Sensitive Paint (PSP) has a capability of providing high-resolution images, but the Signal-to-Noise Ratio (SNR) not enough analyze structures in low-speed flow. The phase-lock method often applied PSP measurement periodic difficult apply this technique containing natural disturbances amplitude and phase. solve problem, we propose new type which images...

Pressure-Sensitive Paint (PSP) applied to the wing surface of a full-span airplane model was tested in European Transonic Windtunnel (ETW) at cryogenic conditions. To deal with issues caused by deformation between wind-on and reference conditions, two-gate lifetime-based PSP method used. The measurements were performed test conditions temperature range from 115K 296 K, M = 0.85 total pressure up 345 kPa. maximum Reynolds number achieved these tests 42.5x106. obtained results successfully...

The capability of a lifetime-based Pressure-Sensitive Paint (PSP) method for application in cryogenic wind tunnels was investigated. relevant experiments were conducted the Pilot-European Transonic Windtunnel (PETW). 2D airfoil model (CAST10-II) painted with PtTFPP/PTMSP paint and tested nitrogen atmosphere at 150 K. PSP pressure tap data acquired Mach 0.78 total 160 kPa. oxygen concentration flow set to 1000 ppm by continuously supplying dry air. As result, successfully visualized...

The prediction of the boundary-layer transition is more important nowadays in aircraft design for reduction flight-related carbon dioxide emissions through use natural laminar flow technology. Temperature Sensitive Paint (TSP) a useful optical measurement technique visualization on model surface. Currently single-component TSP (1C-TSP) has been commonly used cryogenic temperature range but it hard to same ambient due luminescent intensity. In previous work, two-component (2C-TSP) had...

In order to improve the data productivity of a wind tunnel test, model under investigation in is moved continuously with predetermined constant angular speed so-called pitch–traverse mode. Alternatively, can be pitch–pause mode, which it keeps its position for certain (measurement) time at fixed pitch position, after next position. The latter procedure more time-consuming, so, same interval, number measured points taken mode less than that Since test quite expensive, most tests where only...

The pressure-sensitive paint technique based on the heterodyne method was proposed for precise pressure measurement of unsteady flow fields. This is realized by detecting beat signal that results from interference between a modulating illumination light source and fluctuation. captured camera with considerably lower frame rate than frequency By carefully adjusting rate, at interest detected, while noise signals other frequencies are eliminated. To demonstrate method, we measured fluctuations...

The capability of the Pressure-Sensitive Paint (PSP) method for application in unsteady flow cryogenic wind tunnels was investigated. experiments were conducted Cryogenic Ludwieg-Tube Goettingen (KRG). suction side 2-D airfoil model LV2F coated with PtTFPP/PTMSP and tested a nitrogen atmosphere. measurements performed at test conditions temperature range from 120 to 283 K, Mach numbers M = 0.72, 0.74, 0.76, 0.78 chord Reynolds number up Re 14.6 x 10^6. PSP conventional pressure data acquired...

Abstract cntTSP is a flow visualization technique that combines temperature-sensitive paint (TSP) and carbon nanotube (CNT). TSP sprayable temperature sensor, CNT used as thin inner electric heater for the TSP. The allows of movement boundary layer transition on moving airfoil. In this study, was applied to pitch-oscillating airfoil in low-speed wind tunnel. Three methods were compared detecting position. position successfully evaluated using heat transfer coefficient calculated by surface...

An investigation by means of the Pressure-Sensitive Paint (PSP) technique for use in the European Transonic Windtunnel (ETW) is reported in this paper. The so called two-gate lifetime-based PSP method used cryogenic application, especially to avoid problems caused model deformation between wind-on and reference conditions. In first part paper, preliminary tests perforrned Pilot-ETW (PETW) are introduced. New camera LED settings an automated data acquisition system were evaluated at...

The applicability of frequency-domain fluorescence lifetime imaging (FLIM) with a newly developed CMOS camera sensor (pco.flim) to Pressure-Sensitive Paint (PSP) measurements in wind tunnel tests was investigated. Two parameters, the phase angle and demodulation index, can be used as function pressure FLIM technique. First, characteristics FLIM-PSP technique were examined calibration tests. two shift modulation show different sensitivity temperature. This indicates potential simultaneous...

A combination of carbon nanotube and Temperature Sensitive Paint (cntTSP) has a potential to visualize dynamic movement the boundary-layer transition on model surface. One wide area application for use cntTSP is continuous pitch-sweep tests, which are desired in order improve data productivity wind tunnel. In this paper, applicability moving (pitch-sweep test) investigated low-speed tunnel with simplified airplane wing. Two TSP measurement methods, intensity single-shot lifetime method, two...

Abstract This work provides an overview of aerodynamic data acquired in the European Transonic Windtunnel using XRF-1 transport aircraft configuration both at cruise conditions and edges flight envelope. The goals design wind tunnel test were described, highlighting use cryogenic tunnel’s capability to isolate effects $$M_{\infty }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>M</mml:mi> <mml:mi>∞</mml:mi> </mml:msub> </mml:math> , $${\text{Re}}_{\infty...

At given nozzle to plate spacings, the flow field of high speed impinging jets is known be characterized by a resonance phenomenon. Large coherent structures that convect downstream and impinge on surface create strong acoustic waves interact with inherently unstable shear layer at exit. This feedback mechanism, driven in jet layer, can either axisymmetric or helical nature. Fast response pressure sensitive paint applied impingement map unsteady distribution associated these resonant modes....

We succeeded in obtaining PSP (Pressure-Sensitive Paint) measurements for a rugby ball. It was found that the seam of ball is trigger initiating low pressure. Therefore, slower spinning fluctuates during flight because asymmetrical pressure distribution on sides Based results from measurements, multi-objective optimization fluctuating punted kick carried out, and then trade-offs between objective functions control variables could be visualized using Self-Organizing Maps. higher spin rate at...