Control of High-Speed Flows Using Helium Injection
Abstract
Here, we summarize the results of our investigation of means for controlling high-speed flows using helium injection, first demonstrated by Auvity et al., with particular emphasis on the wavefront distortion of light transmitted through the boundary layer. Quantitative estimates of wavefront distortion were obtained, with and without helium injection, and new diagnostic techniques were developed, including a MHz rate Hartmann wavefront sensor. In particular, we demonstrated the ability to capture real-time wavefront data in two dimensions using an ultra-fast Shack-Hartmann sensor in hypersonic and transonic turbulent boundary layers. These measurements are unrivalled in their temporal resolution (2 Os), while providing full dimensional information on the planer field. This capability, and the data in themselves, are vital for making accurate and complete estimates of aero-optic distortion due to boundary layer turbulence in air-borne laser applications, and to assess quantitatively the effectiveness of control methods.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 21, 2005
- Accession Number
- ADA436229
Entities
People
- Alexander Smits
- Richard B. Miles
Organizations
- Princeton University