Accession Number:

ADA281386

Title:

High Altitude Hypersonic Flowfield Radiation

Descriptive Note:

Final rept. 1 Jan 1990-31 Mar 1994

Corporate Author:

STANFORD UNIV CA DEPT OF AERONAUTICS AND ASTRONAUTICS

Personal Author(s):

• MacCormack, Robert W.
• Chapman, Dean R.

Report Date:

1994-04-01

Pagination or Media Count:

9.0

Abstract:

Methods for computing radiation spectra and intensity are compared with available experimental data from three flight tests and five laboratory experiments. These involve both nonequilibrium and equilibrium flow. The comparison was facilitated by development of an improved radiation code, termed NEQAIR 2, incorporating vectorized programming to enable fine-structure spectra to be computed in a practical amount of time. The main sources of computational inaccuracy are found to stem from imperfect understanding of. 1 what temperature or combination thereof in a multi-temperature flowfield governs electronic excitation 2 the physics of rotational relaxation at very high temperatures and 3 the reaction rates for NO production at very high temperatures. Computed radiation is most accurate at low altitudes and hypersonic velocities, and least accurate at high altitudes and velocities. Flowfield radiation, Hypersonic, Nonequilibrium, Spectra.

Descriptors:

• *THERMAL RADIATION
• *HYPERSONIC FLOW
• TEST AND EVALUATION
• VELOCITY
• FLIGHT TESTING
• EXPERIMENTAL DATA
• REACTION KINETICS
• HIGH TEMPERATURE
• COMPARISON
• COMPUTER PROGRAMMING
• INTENSITY
• COMPUTATIONAL FLUID DYNAMICS
• FLOW FIELDS
• HIGH ALTITUDE
• NONEQUILIBRIUM FLOW
• NITROGEN OXIDES
• AEROTHERMODYNAMICS

Subject Categories:

• Aerodynamics
• Fluid Mechanics
• Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE