Further Investigation of the Support System Effects and Wing Twist on the NASA Common Research Model

Abstract

An experimental investigation of the NASA Common Research Model was conducted in the NASA Langley National Transonic Facility and NASA Ames 11-foot Transonic Wind Tunnel Facility for use in the Drag Prediction Workshop. As data from the experimental investigations was collected, a large difference in moment values was seen between the experiment and computational data from the 4 th Drag Prediction Workshop. This difference led to a computational assessment to investigate model support system interference effects on the Common Research Model. The results from this investigation showed that the addition of the support system to the computational cases did increase the pitching moment so that it more closely matched the experimental results, but there was still a large discrepancy in pitching moment. This large discrepancy led to an investigation into the shape of the as-built model, which in turn led to a change in the computational grids and re-running of all the previous support system cases. The results of these cases are the focus of this paper. Nomenclature b= wing span, in. c = wing mean aerodynamic chord, in. = CRM wing/body/tail=0° configuration WBT0ss = CRM wing/body/tail=0° with support system configuration WBT0ssa = CRM wing/body/tail=0° with support system and arc sector configuration x/c = longitudinal distance from wing leading edge nondimensionalized by local wing chord α = angle-of-attack, degrees δ = change in per unit area values η = fraction of wing semi-span φ = radial station, degrees Δ = change in total values

Validation of a near-body and off-body grid partitioning methodology for aircraft aerodynamic performance prediction

“…For the wing-body geometry in these aerodynamic conditions, the experimental measurement in the National Transonic Facility (NTF) of NASA [28] gives a drag level of 248 counts. However, as mentioned in recent articles [29], studies carried out by NASA in 2012 revealed that the experimental model and the numerical geometry provided by the DPW Committee (and used in this article for all the computations) had different wing twists at the design point. Furthermore, in the experiments, laminar zones were present up to 10% chord whereas the CFD calculations are fully turbulent.…”

CFL3D, FUN3D, and NSU3D Contributions to the Fifth Drag Prediction Workshop

“…Including the support system causes a shift in pitching moment as noted in a computational investigation. 17 This was verified in an additional computational investigation, 18 where adjusting the wing twist caused an additional shift in predicted pitching moment toward the wind tunnel measurements. …”

Support interference corrections of a common research model with flying-wing configuration

“…From the figure we can see that lift and drag coefficient of the CFD with support is less than those of the CFD without support, thus effects of support interference decrease lift and drag coefficient [6][7][8]. The comparison of contours of pressure distributions on the upper surface between the flying-wing model with support and the flying-wing model without support at 0 angle of attack is illustrated in Figure 4.…”