Hypersonic Laminar Instability on Round Cones Near Zero Angle of Attack

Reliable predictions for hypersonic laminarturbulent transition will have to be based on simulation of the transition mechanisms. Accurate simulation of the second-mode instability-wave growth on a round cone at zero angle of attack would be a significant step toward this goal. Hypersonic stability experiments in this geometry are reviewed, and three are selected. Extensive and previously unpublished data from Stetson’s sharp and blunt cone experiments are reported. Approximate computations were carried out using inviscid-boundary-layer and e methods. The experimental results are compared to previous high-accuracy computations and to the present approximate computations. Quantitative agreement is at present insufficient for reliable e predictions. The difficulties with both experiment and computation are described.