AN IMPROVED ENTRAINMENT RATE MEASUREMENT METHOD FOR TRANSIENT JETS FROM 10 KHZ PARTICLE IMAGE VELOCIMETRY

2017 ◽  
Vol 27 (6) ◽  
pp. 531-557 ◽  
Author(s):  
W. Ethan Eagle ◽  
Mark P. B. Musculus ◽  
Louis Marie C. Malbec ◽  
Gilles Bruneaux
2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Daniel J. Sherwin ◽  
Jon D. Koch

The time-averaged characteristics of a fuel jet have been measured via acetone planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) in the primary mixing region of an operating gas-fired water heater. These measurements allow for experimental characterization of the cross-sectional scalar and velocity fields as well as the estimation of the mass entrainment as the flow enters the burner in a practical system. In these experiments, reasonable results were obtained when only the fuel jet was seeded with acetone or PIV particles rather than the entire flow, thus demonstrating the potential for simplified experimental configurations in some applications where controlling or seeding the entire flow may be difficult. The entrainment characteristics of the fuel jet are compared with benchmarks from literature. The commercial device exhibits a larger mass entrainment rate than is found in typical free jets that have been studied in the literature. This may be a result of the jet's low Reynolds number (9,600) in comparison with other literature studies, and a result of initial conditions.


Author(s):  
W Choi ◽  
B-C Choi

The air entrainment characteristics of a transient high-pressure diesel spray were investigated with respect to time and location for injection pressures ( Pinj = 76 or 137 MPa) and ambient density (ρa = 15.6 kg/m3) under the non-evaporating condition (303 K). A particle image velocimetry analysis was introduced and some parameters were defined to express air entrainment characteristics. The air entrainment rate increased greatly as the flow moved downstream owing to a larger contact surface area and a recirculating flow. Higher pressure led to a greater entrainment rate with higher effectiveness. The speed (spray tip and front ambient gas) and volume (spray and laterally entrained gas) relations suggested the possibility for the renewal against the lateral-dominant entrainment mechanism.


2019 ◽  
Vol 20 (8) ◽  
pp. 811 ◽  
Author(s):  
Damien Cabut ◽  
Marc Michard ◽  
Serge Simoens ◽  
Violaine Todoroff ◽  
Jean Lemaître ◽  
...  

A measurement method based on Particle Image Velocimetry (PIV) with refraction of the laser sheet at a window/water interface is proposed for the measurement of the velocity field of a flow, inside a water puddle, due to a tire rolling on. This study focuses on the feasibility and repeatability of this optical measurement method. The characterization of the optical properties of this measurement technique defines its accuracy. The analysis of the overall features of the flow is focused on two main flow zones in front of and around the tire. The flow inside the first zone is characterized by a global velocity of the water displaced in an area located in front of the tire. In the second zone a velocity representative of the flow in the vicinity of the tire shoulder is also defined. Correlations of both characteristic velocities with the car speed and water film height are established. New and the corresponding worn tires were tested in this work.


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