Hot-Film Velocity Measurement Uncertainty for DARPA SUBOFF Experiments
Abstract
The uncertainty associated with measuring the three-component velocity for the DARPA suboff experiments has been investigated. Bias uncertainty due to temperature variation, probe alignment, analog to digital conversion, speed calibration and angle calibration resulted in an overall 2 sigma bias uncertainty of + or - 2.21% for u/U sub ref and + or - 2.28% for v/W sub ref 1.79% for w/U sub ref. Precision (random) 2 sigma uncertainty depended slightly on turbulence intensity levels. For low turbulence intensity levels (TI approx 0.5%), precision uncertainty was + or - 0.04% for u/U ref, + or - 0.04% for v/U sub ref, and + or - 0.06% for w/U sub ref. For high turbulence intensity levels (TI approx 4%), precision uncertainty was + or - 0.28% for u/U sub ref, + or - 0.16% for v/U sub ref, and + or - 0.20% for w/U sub ref.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1990
- Accession Number
- ADA220002
Entities
People
- Jame N. Blanton
- L. P. Purtell
- Thomas J. Forlini