Thrust Coefficients of Low-Thrust Nozzles
Abstract
The performance losses associated with small nozzles operating at low propellant flow rates were investigated experimentally with a resistance-heated hydrogen thrustor. Data were obtained for seven different nozzles covering the range of nozzle area ratio from 25 to 150, hydrogen propellant flow rates of 0.5x10 to the -4, 1.0x10 to the -4, and 2.5x10 to the -4 pound per second, and propellant temperatures from 530 to 4000 R. The nozzle losses, as determined by the difference between the one-dimensional isentropic thrust coefficient and the measured thrust coefficient, were correlated in terms of the throat Reynolds number and nozzle area ratio. At low throat Reynolds number, the nozzle losses were sufficiently large to result in measured thrust coefficients less than the values calculated for isentropic flow through a choked orifice. Results show that large area ratios are not required for achieving maximum thrust for nozzles with low throat Reynolds number (<10 000).
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1965
- Accession Number
- ADA400724
Entities
People
- Ernie W. Spisz
- John R. Jack
- Paul F. Brinich
Organizations
- National Aeronautics and Space Administration