TY - GEN
T1 - Near-wall stereo PIV investigation of the turbulent channel flow over rough-walls
AU - Hong, Jiarong
AU - Katz, Joseph
AU - Schultz, Michael
PY - 2009/9/18
Y1 - 2009/9/18
N2 - The near-wall turbulent flow in the rough-wall channel is of great significance in engineering applications, but remains a challenge for both experimental measurement and numerical modeling due to the complexity of the roughness geometry. For optical measurement techniques, e.g. PIV, obstruction by the roughness elements and reflection from the surface adversely affect the quality of near wall data. Our present study utilizes a facility containing a fluid with the same refractive index as the rough acrylic wall, making the interface almost invisible, and employs Stereo PIV to obtain the three-dimensional flow field in the vicinity of the roughness elements. The roughness shape is a uniformly distributed and closely packed, 0.5 mm high pyramid, corresponding to 95 wall units, with a pitch angle of 22.5 degrees. The length of the rough surface is sufficiently long to obtain self-similar roughness boundary layer, turbulent channel flow at a mean velocity of 3.8 m/s, with a clearly defined log layer. Results will include sample data of the complete flow, both around and above the roughness elements. Issues related to implementation of Stereo PIV in an index-matched facility will be discussed.
AB - The near-wall turbulent flow in the rough-wall channel is of great significance in engineering applications, but remains a challenge for both experimental measurement and numerical modeling due to the complexity of the roughness geometry. For optical measurement techniques, e.g. PIV, obstruction by the roughness elements and reflection from the surface adversely affect the quality of near wall data. Our present study utilizes a facility containing a fluid with the same refractive index as the rough acrylic wall, making the interface almost invisible, and employs Stereo PIV to obtain the three-dimensional flow field in the vicinity of the roughness elements. The roughness shape is a uniformly distributed and closely packed, 0.5 mm high pyramid, corresponding to 95 wall units, with a pitch angle of 22.5 degrees. The length of the rough surface is sufficiently long to obtain self-similar roughness boundary layer, turbulent channel flow at a mean velocity of 3.8 m/s, with a clearly defined log layer. Results will include sample data of the complete flow, both around and above the roughness elements. Issues related to implementation of Stereo PIV in an index-matched facility will be discussed.
UR - http://www.scopus.com/inward/record.url?scp=70249120748&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70249120748&partnerID=8YFLogxK
U2 - 10.1115/FEDSM2008-55197
DO - 10.1115/FEDSM2008-55197
M3 - Conference contribution
AN - SCOPUS:70249120748
SN - 9780791848418
T3 - 2008 Proceedings of the ASME Fluids Engineering Division Summer Conference, FEDSM 2008
SP - 683
EP - 690
BT - 2008 Proceedings of the ASME Fluids Engineering Division Summer Conference, FEDSM 2008
T2 - 2008 ASME Fluids Engineering Division Summer Conference, FEDSM 2008
Y2 - 10 August 2008 through 14 August 2008
ER -