Interior Spectroscopic Investigation of the Propellant Energy Modes in an Arcjet Nozzle
Abstract
Internal emission spectroscopy measurements were performed in the nozzle expansion region of a 26 kW class ammonia arcjet. A series of three optical access ports (0.020-inch diameter) were equally spaced along the center line of the expansion nozzle. Atomic and ionic excitation temperatures of H and NII were determined through the use of Boltzmann plots. Electron density measurements were also taken based upon Stark broadening of the hydrogen beta Balmer transition. It is believed that a change in the mechanism governing the electron density occurred just downstream of the constrictor between the first two access ports lending evidence that arc attachment is occurring in this region. Although the trends for excitation temperatures and electron density were similar to those previously observed in 1 kW arcjets, the temperature values were found to be significantly less. In addition, vibrational and rotational temperatures of NH were measured and appeared to be frozen throughout the expansion nozzle.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1994
- Accession Number
- ADA436571
Entities
People
- Michael M. Micci
- Ronald A. Spores
- William A. Hargus , Jr.
Organizations
- Pennsylvania State University