TY - JOUR
T1 - Effects of nozzle pressure ratio and nozzle-to-plate distance to flowfield characteristics of an under-expanded jet impinging on a flat surface
AU - Nguyen, Duy Thien
AU - Maher, Blake
AU - Hassan, Yassin
N1 - Publisher Copyright:
© 2019 by the authors.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - The current work experimentally investigates the flowfield characteristics of an under-expanded turbulent jet impinging on a solid surface for various nozzle-to-plate distances 2.46Dj, 1.64Dj, and 0.82Dj (Dj is the jet hydraulic diameter), and nozzle pressure ratios (NPRs) ranging from 2 to 2.77. Planar particle image velocimetry (PIV) measurements were performed in the central plane of the test nozzle and near the impingement surface. From the obtained PIV velocity vector fields, flow characteristics of under-expanded impinging jets, such as mean velocity, root-mean-square fluctuating velocity, and Reynolds stress profiles, were computed. Comparisons of statistical profiles obtained from PIV velocity measurements were performed to study the effects of the impingement surface, nozzle-to-plate distances, and NPRs to the flow patterns. Finally, proper orthogonal decomposition (POD) analysis was applied to the velocity snapshots to reveal the statistically dominant flow structures in the impinging jet regions.
AB - The current work experimentally investigates the flowfield characteristics of an under-expanded turbulent jet impinging on a solid surface for various nozzle-to-plate distances 2.46Dj, 1.64Dj, and 0.82Dj (Dj is the jet hydraulic diameter), and nozzle pressure ratios (NPRs) ranging from 2 to 2.77. Planar particle image velocimetry (PIV) measurements were performed in the central plane of the test nozzle and near the impingement surface. From the obtained PIV velocity vector fields, flow characteristics of under-expanded impinging jets, such as mean velocity, root-mean-square fluctuating velocity, and Reynolds stress profiles, were computed. Comparisons of statistical profiles obtained from PIV velocity measurements were performed to study the effects of the impingement surface, nozzle-to-plate distances, and NPRs to the flow patterns. Finally, proper orthogonal decomposition (POD) analysis was applied to the velocity snapshots to reveal the statistically dominant flow structures in the impinging jet regions.
KW - Particle image velocimetry
KW - Proper orthogonal decomposition
KW - Under-expanded impinging jet
KW - Velocity measurements
UR - http://www.scopus.com/inward/record.url?scp=85060459811&partnerID=8YFLogxK
U2 - 10.3390/aerospace6010004
DO - 10.3390/aerospace6010004
M3 - Article
AN - SCOPUS:85060459811
SN - 2226-4310
VL - 6
JO - Aerospace
JF - Aerospace
IS - 1
M1 - 4
ER -