Effect of Turbulent Fluctuations on Infrared Radiation from a Tactical Missile Plume
Abstract
Predictions of the effect of turbulent fluctuations of temperature and species concentrations on the infrared thermal emission from an afterburning exhaust plume of a tactical missile are summarized. The high spectral resolution emissions from portions of the 4.3 micrometers CO2 band are examined. A consistent set of mean flow and turbulence properties in the plume obtained from a second-order closure model of the turbulent flow is used in the calculation. A precise closure model of the turbulent flow is used in the calculation. A precise formulation of the mean radiance is given which includes contributions of second-order turbulence correlations and explicitly identifies the contribution of two-point spatial correlations along the line of sight. These correlations are shown to affect the structure of individual spectral lines for non-optically thin paths. Total plume intensities in narrow 5 cm to the minus 1 power wide spectral intervals in the CO2 blue and red spike regions are not significantly augmented by the turbulent fluctuations for this class of afterburning plumes. Turbulence augmentation is most important in the lower temperature outer edges of the plume and regions of downstream decay. The situations where turbulence augmentation could be an important contributor to total turbulence augmentation could be an important contributor to total plume intensities and to exhaust plume diagnostics are identified.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1982
- Accession Number
- ADA117013
Entities
People
- Ashok K. Varma
- Blaine E. Pearce