Image measurements of unsteady pressure fluctuation by a pressure-sensitive coating on porous anodized aluminium

Pressure-sensitive luminescent coating on porous anodized aluminium (AA-PSP) was applied to measure non-periodic unsteady pressure distribution on a wind-tunnel model. A high-speed digital video camera was used to capture the PSP signal. The pressure-sensitive dye was tris(4,7-diphenylphenanthroline) ruthenium(II) ([Ru(dpp)3]2+). The coating has a short response time of O(10 µs), although it exhibits temperature and humidity sensitivities. A hydrophobic coating was applied on the anodized aluminium surface to suppress the humidity sensitivity. A temperature sensitive paint was used to obtain the temperature distribution instantaneously with the pressure. The temperature data were used to correct the PSP response. An appropriate data acquisition procedure as well as digital image processing algorithm was established to compensate for the error from the temperature and humidity sensitivities. The present system was applied to measure the pressure distribution on a delta wing at a high angle of attack in transonic flow, whose flow is unsteady due to the interaction between shock waves and leading edge vortices. The non-periodic unsteady pressure distribution on the delta wing was successfully measured with the sampling rate of 1 kHz and within a few per cent error in absolute pressure level.

[1]  I. Gursul.  Recent developments in delta wing aerodynamics , 2004, The Aeronautical Journal (1968).

[2]  J. Bell,et al.  Surface Pressure Measurements Using Luminescent Coatings , 2003 .

[3]  J. Callis,et al.  Submillisecond response times of oxygen‐quenched luminescent coatings , 1993 .

[4]  James W. Gregory,et al.  POROUS PRESSURE-SENSITIVE PAINT FOR MEASUREMENT OF UNSTEADY PRESSURES IN TURBOMACHINERY , 2004 .

[5]  James W. Gregory,et al.  Porous Pressure-Sensitive Paint for Characterizing Unsteady Flowfields , 2002 .

[6]  A. Kurdila,et al.  Model Development and Analysis of the Dynamics of Pressure-Sensitive Paints , 2001 .

[7]  J. Délery.  Aspects of vortex breakdown , 1994 .

[8]  Hiroshi Kanda,et al.  Sample Tests of Pressure-Sensitive Paints with 49 Different Formulations , 1997 .

[9]  K. Asai,et al.  Adsorptive pressure-sensitive coatings on porous anodized aluminium , 2004 .

[10]  Bryan Campbell,et al.  Temperature- and Pressure-Sensitive Luminescent Paints in Aerodynamics , 1997 .

[12]  D. G. Mabey,et al.  Some Aspects of Aircraft Dynamic Loads Due to Flow Separation Meeting (65th) Held in Cesme, Turkey on 4-9 October 1987 , 1988 .

[13]  J. Sullivan,et al.  Porous Polymer/Ceramic Composites for Luminescence-Based Temperature and Pressure Measurement , 1999 .

[14]  Tianshu Liu,et al.  Pressure and Temperature Sensitive Paints , 2004, Experimental Fluid Mechanics.

[15]  W. J. Bannink,et al.  Surface Reflective Visualizations of Shock-Wave/Vortex Interactions Above a Delta Wing , 1997 .

[16]  K. Wada,et al.  Optical Transmittance of Anodically Oxidized Aluminum Alloy , 1995 .

[17]  M. Kameda,et al.  Hydrophobic monolayer coating on anodized aluminum pressure-sensitive paint , 2006 .

[18]  John P. Sullivan,et al.  Time Response of Anodized Aluminum Pressure-Sensitive Paint , 2001 .

[19]  Hiroshi Kanda,et al.  Surface pressure measurement in a cryogenic wind tunnel by using luminescent coating , 1997, ICIASF'97 Record. International Congress on Instrumentation in Aerospace Simulation Facilities.

[20]  Y. Ikeda,et al.  Optical measurements of high-frequency pressure fluctuations using a pressure-sensitive paint and Cassegrain optics , 2002 .

[21]  K. Asai,et al.  Pressure-Sensitive Paint Application to a Wing-Body Model in a Hypersonic Shock Tunnel , 2002 .

[22]  Y. Sakamura,et al.  High frame-rate imaging of surface pressure distribution using a porous pressure-sensitive paint , 2005 .