Axisymmetric Coanda-Assisted Vectoring

• Main Author: Allen, Dustin S
• Format: Others
• Published: DigitalCommons@USU 2008
• Subjects: Coanda effect; jet vectoring; thermal spray; parallel jets; particle image velocimetry; Mechanical Engineering
• Online Access: https://digitalcommons.usu.edu/etd/90; https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1096&context=etd

An examination of parameters affecting the control of a jet vectoring technique used in the Coanda-assisted Spray Manipulation (CSM) is presented. The CSM makes use of an enhanced Coanda effect on axisymmetric geometries through the interaction of a high volume primary jet flowing through the center of a collar and a secondary high-momentum jet parallel to the first and adjacent to the convex collar. The control jet attaches to the convex wall and vectors according to known Coanda effect principles, entraining and vectoring the primary jet, resulting in controllable r-θ directional spraying. Several control slots (both annular and unique sizes) and expansion radii were tested over a range of momentum flux ratios to determine the effects of these variables on the vectored jet angle and profile. Two- and three-component Particle Image Velocimetry (PIV) was used to determine the vectoring angle and the profile of the primary jet in each experiment. The experiments show that the control slot and expansion radius, along with the momentum ratios of the two jets, predominantly affected the vectoring angle and profile of the primary jet. The Reynolds number range for the primary jet at the exit plane was between 20,000 and 80,000. The flow was in the incompressible Mach number range (Mach< 0.3).