One effect of using pressure sensitive paint (PSP) is the potential intrusiveness to the aerodynamic characteristics of the model. The paint thickness and roughness may affect the pressure distribution, and therefore, the forces and moments on the wind tunnel model. A study of these potential intrusive effects was carried out at NASA Langley Research Center where a series of wind tunnel tests were conducted using the Modem Design of Experiments (MDOE) test approach. The PSP effects on the integrated forces were measured on two different models at different test conditions in both the Low Turbulence Pressure Tunnel (LTPT) and the Unitary Plan Wind Tunnel (UPWT) at Langley. The paint effect was found to be very small over a range of Reynolds numbers, Mach numbers and angles of attack. This is due to the very low surface roughness of the painted surface. The surface roughness, after applying the NASA Langley developed PSP, was lower than that of the clean wing. However, the PSP coating had a localized effects on the pressure taps, which leads to an appreciable decrease in the pressure tap reading.
[1]
H. Schlichting.
Boundary Layer Theory
,
1955
.
[2]
R. C. Crites.
Pressure sensitive paint technique
,
1993
.
[3]
K. Schanze,et al.
Temperature Dependence of Pressure Sensitive Paints
,
1997
.
[4]
M E Sellers.
Pressure Sensitive Paint Data on the Transonic Technology Wing Demonstrator (TST) in the AEDC Propulsion Wind Tunnel 16T
,
1998
.
[5]
Michael E. Olsen,et al.
The effects of thin paint coatings on the aerodynamics of semi-span wings
,
1998
.
[6]
R. DeLoach.
The Modern Design of Experiments: A Technical and Marketing Framework
,
2000
.
[7]
F. Vanhoutte,et al.
Intrusion effects of pressure sensitive paint in wind-tunnel tests on wings
,
2000
.
[8]
R. DeLoach.
Improved Quality in Aerospace Testing Through the Modern Design of Experiments
,
2000
.