1. Computations were also carried out for the flow ahout a blunted 2-D wedge which has the same cross section as that of the 3-0 delta wing at the vertical midplane. Although the two flows are very much different in character, the 2-D wedge flow was used to study grid effects resulting from different cell sizes and cell distributions, since these questions are more efficiently investigated in a 2-D flow. This information was used to arrive at an appropriate grid for the 3-0 computations. Figures 10 through 12 present surface pressure, heattransfer rate, and shear stress results near the symmetry plane for the 3-D flow, along with the 2-D flow reeults for comparison. For the 2-D flaw, the stagnation paint (where the shear stress is zero and surface pressure and heating reach their msxima) is very close to the nose apex. In the case of 3-0 flow, the stagnation point is located on the sharp V edge, and the shear stress at the stagnation point is not zero hecause of the singularity created by the surface slope discontinuity. In other words, it is not possible to locate the stagnation point for the 3-0 flow frcm Pig. 12. However, peak values far the surface pressure and heating i/ (Figs. 8 through 11) suggest that the stagnation point occurs around x = 0.002 m on the windward side of the delta wing's nose.
2. In the past, the DSMC method has been successfully applied to various axisymmetric and 2-D transitional flow problems 3 and more recently to complicated 3-0 flow cases* with a reasonable amount of computational time. The results presented in this paper are a part of ongoing research efforts for the application of the DSMC method to complicated 3-D configurations.
3. One of the reasons for studying this flow is the availability of experimental data far comparison. Allegre' and his co-workers at CNRS in Prance have conducted the experiments for this flow in their low-density hypersonic wind tunnel and obtained data for the leeside density profiles and total body forces. The experimental data will be available to the public (and the present authors) after January 1990.
4. Thirdly, Figs. 10 through 12 show that on the windward side of the delta wing, the density (not shown) and surface pressure are lower but the heat-transfer and shear stress results are higher than the 2-D wedge flow results. This is expected because in the delta-wing case, the freestream flow encounters a mch smaller body than in the 2-D case, resulting in a smaller disturbance field in front of the delta wing than for the 2-0 case. This gives rise to the above mentioned surface results which are analo ous to the findings of past comparative studies.71