Ares I Aerodynamic Testing at the Boeing Polysonic Wind Tunnel

Abstract

Throughout three full design analysis cycles, the Ares I project within the Constellation program has consistently relied on the Boeing Polysonic Wind Tunnel (PSWT) for aerodynamic testing of the subsonic, transonic and supersonic portions of the atmospheric flight envelope (Mach=0.5 to 4.5). Each design cycle required the development of aerodynamic databases for the 6 degree-of-freedom (DOF) forces and moments, as well as distributed line-loads databases covering the full range of Mach number, total angle-of-attack, and aerodynamic roll angle. The high fidelity data collected in this facility has been consistent with the data collected in NASA Langley's Unitary Plan Wind Tunnel (UPWT) at the overlapping condition of Mach=1.6. Much insight into the aerodynamic behavior of the launch vehicle during all phases of flight was gained through wind tunnel testing. Important knowledge pertaining to slender launch vehicle aerodynamics in particular was accumulated. In conducting these wind tunnel tests and developing experimental aerodynamic databases, some challenges were encountered and are reported as lessons learned in this paper for the benefit of future crew launch vehicle aerodynamic developments. Nomenclature Symbols

Enhancements to TetrUSS for NASA Constellation Program

“…These predicted results aided wind-tunnel model design, protuberance fabrication, test matrix development, and instrumentation in the region of major flow variations. The predictions were also validated against subsequently available wind-tunnel test measurements [28][29][30]. A good correlation [24] between USM3D predictions and wind-tunnel data further added confidence in the validity of the CFD results.…”

“…The Ares I ADAC-2B A103 configuration has been tested at three wind-tunnel facilities [28][29][30] covering low subsonic to high supersonic flow conditions and low to high Reynolds number. Figure 8 presents a sample comparison [24] of a USM3D solution with wind-tunnel measurements for this configuration at Mach 1.6, an angle of attack of 7 deg, and low-Reynolds-number wind-tunnel conditions.…”

Detailed Uncertainty Analysis of the Ares I A106 Liftoff/Transition Database

“…8 The Tower Increments DB total uncertainties were computed by substituting the results for each uncertainty source into the general buildup equation shown in Eq. (3). None of the uncertainty terms for the Tower Increments DB showed a significant dependence on any independent variable, and so the entire database domain had a single constant uncertainty for each coefficient.…”

“…The Ares I aerodynamics team, spanning several NASA centers, conducted extensive aerodynamic testing and computational simulations in support of the overall vehicle integration effort [1][2][3][4][5][6][7], and the papers in the Ares Special Section of this journal detail these efforts. The Ares I guidance, navigation, and control (GNC) team and other customers used uncertainty estimates provided with each aerodynamic database (DB) to perform dispersion analyses and risk assessment.…”

Ares I and Ares I-X Stage Separation Aerodynamic Testing

“…Since only a small part of the calibrated range of the balance was used, this partly explains the higher uncertainties determined for rolling moment results. More details on this topic are discussed by Pinier et al [7]. Best practices related to the calibration and use of internal strain gage balances as described by the AIAA Recommended Practices [8] were consistently followed during testing.…”