AN UNCOOLED, RAPID RESPONSE PROBE FOR MEASURING STAGNATION PRESSURES IN HIGH VELOCITY ARC PLASMA.
Abstract
A means for measuring stagnation pressures in high temperature, high current plasmas is described. The device employs a small (< .060 in. o.d.) uncooled pitot tube designed for minimum response time (< .001 sec.) which is rapidly swept through the plasma flow field (< .015 sec.). A simple technique for evaluating the transient response of the probe is described. Because the probe tip is inexpensive and expendable, a moderate amount of molten phase ablation is tolerable in the stagnation zone. Consequently, it appears possible to obtain meaningful results at heat flux rates exceeding 10,000 cal/sq. cm -sec., which is one to two orders of magnitude greater than have thus far been tolerable with water-cooled probes. In preliminary tests a single probe was successfully employed for eight successive measurements of total pressure in an atmospheric pressure, air-arc plasma at currents ranging from 200 to 1000 amperes at Mach numbers close to unity. Heat flux rates encountered are estimated to be in the vicinity of 2000-3000 cal sq./cm sec. The principle merits of the probe described are its small size, rapid response and its inexpensive, expendable probe tip.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1964
- Accession Number
- AD0609621
Entities
People
- A. M. Whitman
- P. Barkan
Organizations
- General Electric