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Mcmillin, S. N.

Publications and source records attributed to Mcmillin, S. N..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Euler and Navier-Stokes solutions for the leeside flow over delta wings at supersonic speeds

Distinctly different types of leeside flowfields over highly swept sharp leading edge delta wings in supersonic flow were numerically simulated using Euler and Navier-Stokes solvers. The Euler code was seen to be adequate only in predicting primary flow structures (leading edge vortex and cross flow shock) whereas the Navier-Stokes code was capable of predicting secondary flow structures (i.e., secondary vortex). A comparison of laminar and turbulent Navier-Stokes solutions indicated that the turbulent boundary layer model is more accurate in predicting the effect of the boundary layer model on the flowfield. Also, the Navier-Stokes code indicated detailed flow structures not observed in the qualitative experimental data available (i.e., vapor screen photographs) indicating a need for quantitative flow field data.

Mcmillin, S. N.↗
NASA NTRS1986

Planform effects for low-fineness ratio multibody configurations at supersonic speeds

An experimental and theoretical investigation of planform effects on a low-fineness ratio multibody configuration has been conducted in NASA Langley Research Center's Unitary Plan Wind Tunnel at Mach numbers 1.6, 1.8, 2.0, and 2.16. Experimental and theoretical values of lift, drag, and pitching moment were obtained on three configurations which varied in outboard panel planform only. The three variations were at 65 deg delta, a 70/66 deg cranked arrow, and a 20 deg trapezoidal planform . The purpose of the study was to determine the effect of wing planform on the supersonic aerodynamics and to evaluate the ability of two existing linearized-theory aerodynamic methods to predict these effects. Experimental data showed that the planforms produced the lift, drag-due-to-lift, and pitching-moment characteristics typically found on single-body configurations. However, the data also showed that planform has a minimal influence on zero-lift drag, which is not typical of single-body configurations. Theoretical aerodynamic analysis indicated that codes based on linearized theory adequately predicted the effect of planform on the supersonic aerodynamics.

Mcmillin, S. N.↗