Comparison of Iced Aerodynamic Measurements on Swept Wing from Two Wind Tunnels

Abstract

Artificial ice shapes of various geometric fidelity were tested on a wing model based on the Common Research Model. Low Reynolds number tests were conducted at Wichita State University's Beech Memorial Wind Tunnel, and high Reynolds number tests were conducted at ONERA's F1 wind tunnel. The aerodynamic performance data from the two facilities were compared at matched or similar Reynolds and Mach number to ensure that the results and trends observed at low Reynolds number could be applied and continued to high Reynolds number. For both clean and iced configurations, the data from Wichita State University and F1 agreed well at matched or similar Reynolds and Mach numbers. The lift and pitching moment curves agreed very well for most configurations. There appeared to be 0.2-0.3° offset in the angle of attack between the Wichita State University and F1 data, possibly due to different flow angularities in the test sections of the two facilities. There was also an offset in the drag values between the two facilities from an unknown cause. Overall, the data compared very well between the low Reynolds number test at Wichita State University tunnel and the high Reynolds number test at F1. This indicated that data from the low Reynolds number tests could be used to understand iced-swept-wing aerodynamics at high Reynolds number. Nomenclature b = Model span c = Model chord x = Model coordinate in chordwise direction y = Model coordinate in spanwise direction CD = Drag coefficient CD,0.6 = Drag coefficient at CL = 0.6 CD,min = Minimum drag coefficient CL = Lift coefficient CL.max = Maximum lift coefficient CL,use = Usable lift coefficient CM = Pitching moment coefficient Cp = Pressure coefficient CRM65 = Common Research Model 65% scale M = Mach number MAC = Mean aerodynamic chord ONERA = Office National d'Etudes et Recherches Aérospatiales p0 = Freestream total pressure q = Freestream dynamic pressure Re = Reynolds number RLE = Removable leading edge  = Angle of attack stall = Stall angle of attack  = Sweep angle

Independent Effects of Reynolds and Mach Numbers on the Aerodynamics of an Iced Swept Wing

“…In other words, the actual uncertainties in lift, drag and pitching-moment coefficient for the lowest dynamic pressure are likely much lower than the values reported in Table 3. Lee et al 5 provide further justification for this conclusion by comparison of the data acquired on the 8.9% scale model at the WSU wind tunnel. For the highest dynamic pressure at Re = 11.9×10 6 , M = 0.23, all of the uncertainty values are much more reasonable and acceptable for the purposes of this work.…”

“…Therefore, it is important that the effect of the wind-tunnel walls on the aerodynamic data from both facilities be accounted for properly. The companion paper by Lee et al 5 provides comparison and analysis of the results of the wall correction schemes. The aerodynamic data reported in this paper were corrected using the ONERA method.…”

Summary of Ice Shape Geometric Fidelity Studies on an Iced Swept Wing

“…21 The magnitude of the correction to the angle of attack applied in the WSU facility has been reduced relative to past papers and reports related to this project. 13,14,19 Lee et al 17 describe the motivation for the change to the angle of attack correction. In both facilities, the corrections are performed in real-time as part of the data acquisition process.…”

“…However, the companion paper by Lee et al 17 provides comparison and analysis of the results from the two different facilities.…”

“…Companion papers by Broeren et al, 16 Lee et al, 17 and Sandu et al 18 provide additional details regarding other aspects of these wind tunnel tests. Additionally, this paper will summarize the icing aerodynamic simulation process along with the terminology that has been developed for naming conventions for these various fidelity ice shapes.…”