Experimental determination of strain rates in stretched laminar diffusion flames

A laser Doppler anemometer was used to measure the axial and radial velocity components of hydrogen-air counterflow diffusion flames (CFDF). An axisymmetric opposed jet burner (OJB) used seeded air in one cylindrical tube, and a hydrogen-nitrogen mixture in the opposing cylindrical tube. Velocity measurements were made at four different operating flow rates, and were used to compute the associated strain rate fields. The results were used to qualitatively assess current CFDF modeling schemes, and to expand the knowledge of the fluid velocity field behavior within these flames. The data show behavior qualitatively consistent with most models and experimental studies: the radial velocity is essentially linear with radial position, and the velocity data collapse to functions of axial position only for regions away from the stagnation plane. However, the data also show a variable strain rate field and a relatively thick reaction zone, which are both inconsistent with CFDF models. The axial velocity fields also behaved unexpectedly as the operating flow rates were increased, transitioning from the characteristic N -shaped profile to an asymptotically-approaching profile.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1992

Author dc:creator

• Long, Scott R.

Chair dc:contributor.committeechair

• Dancey, Clinton L.

Committee member dc:contributor.committeemember

• Brown, Eugene F.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en

Dc Identifier Other

etd-08222009-040351

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/44388