CO2 Vibrational Relaxation Effects in a Laser Heated Hypersonic Flow
Abstract
The establishment of flow conditions characteristic of hypersonic flight in a ground test facility by conventional means requires plenum conditions that have very high temperatures and give rise to a variety of materials problems. A well-known approach to solving these problems is to use high-pressure, moderate temperature plenum conditions and add energy as the flow expands through a carefully designed nozzle. A modern approach (Radiatively Heated Wind Tunnel) uses an HF laser to excite the (02'1) mode of CO2 naturally present or added to the flow. One of the early challenges in the development will be to demonstrate the ability to add energy into the supersonic flow in a predictable and controllable manner. Consequently, a subscale experiment, the Laser Demon-stration Device (LDD), is planned to investigate the transfer of laser energy to a small, expanding nozzle flow. Previous modeling of the energy transfer of the laser energy into the gas for the LDD depended on a conventional two-temperature approach to describe the internal structure of the molecules and to determine the rate coefficients. Realizing that the detailed physics of the energy transfer was important to the description of the wind tunnel performance and, hence, its viability, an effort was undertaken to compute the effect of CO2 relaxation using a technique in which the individual vibrational states are considered. Results of these computations are reported here.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1997
- Accession Number
- ADA345777
Entities
People
- C. C. Limbaugh
- J. A. Drakes