A Sampling Probe for Fluctuating Concentration Measurements in Supersonic Flow

The study of mixing processes in supersonic flow has a great interest for a number of applications including scramjet developments. However, the usual tools employed are very limited. Sampling probes generally have a poor frequency response, and that makes measurements of fluctuating concentration problematic. The goal of this study is to design, build and test a probe capable of measuring concentration fluctuations of at least 1 kHz. This study shows the design of such a probe and how a high frequency response was achieved. A prototype was built and tested. The tests consist of a calibration phase and experiments inside a hypersonic wind tunnel. These last tests served two purposes. The first one was to verify that the measurements made with the probe gave the correct value of the concentration. The second purpose was to assess the frequency response of the probe by putting it through a concentration step change. Tests were conducted with various known mixtures of Helium and air from 0% to 100% flowing at Mach 2.0 with T_t=300 °K and P_t=4.4 atm. The probe proved capable of measuring concentration fluctuations up to approximately 2.5 kHz while also giving the adequate accuracy for values of mean concentration.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Aerospace and Ocean Engineering

Department dc:contributor.department

Aerospace and Ocean Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1998

Author dc:creator

• Xillo, Olivier

Chair dc:contributor.committeechair

• Schetz, Joseph A.

Committee members dc:contributor.committeemember

• Ng, Fai
• Simpson, Roger L.

• Fluctuating
• Supersonic
• Concentration
• Measurements

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-41298-124436

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/36670