Sponsor
Ohio Space Grant Consortium
Advisor(s)
Jed Marquart, PhD
Ohio Northern University
Mechanical Engineering
j-marquart@onu.edu
Document Type
Poster
Location
ONU McIntosh Center; Activities Room
Start Date
22-4-2022 11:00 AM
End Date
22-4-2022 12:00 PM
Abstract
A computational fluid dynamics analysis investigating the variation of effects on nozzles with non-orthogonal exit planes, known as scarfing, was performed. The steady Reynolds-averaged Navier-Stokes model, coupled with the Spalart-Allmaras turbulence model, was used to simulate and compare plume development and characteristics using various scarfing geometries at variable inlet conditions. The jet plume cross-section is significantly affected for overexpanded conditions, while retaining the nozzle exit shape for underexpanded conditions, although slight peaks (bifurcation) do occur at the centerline. The same observations occur when slightly changing the angle of scarf. However, inverting the overall geometry of the diverging portion of the nozzle dramatically impacts plume shape and development. At overexpanded conditions, the plume cross-section undergoes substantial deformity as it resembles a mushroom cloud as it moves downstream. For underexpanded conditions, the plume appears as a jagged rectangle before settling into a rectangular shape comparable to underexpanded cases for other geometries. The addition of scarfing also introduced differences in static pressure at the nozzle exit plane, influencing plume development and secondary flow characteristics. The degree of bifurcation lessens and the jet potential core length increases as the conditions move from overexpanded to underexpanded, which was expected.
Recommended Citation
La Sorsa, Andrew J., "Computational Analysis of the Effects of Scarfed Nozzle Variations on Jet Plumes" (2022). ONU Student Research Colloquium. 4.
https://digitalcommons.onu.edu/student_research_colloquium/2022/posters/4
Computational Analysis of the Effects of Scarfed Nozzle Variations on Jet Plumes
ONU McIntosh Center; Activities Room
A computational fluid dynamics analysis investigating the variation of effects on nozzles with non-orthogonal exit planes, known as scarfing, was performed. The steady Reynolds-averaged Navier-Stokes model, coupled with the Spalart-Allmaras turbulence model, was used to simulate and compare plume development and characteristics using various scarfing geometries at variable inlet conditions. The jet plume cross-section is significantly affected for overexpanded conditions, while retaining the nozzle exit shape for underexpanded conditions, although slight peaks (bifurcation) do occur at the centerline. The same observations occur when slightly changing the angle of scarf. However, inverting the overall geometry of the diverging portion of the nozzle dramatically impacts plume shape and development. At overexpanded conditions, the plume cross-section undergoes substantial deformity as it resembles a mushroom cloud as it moves downstream. For underexpanded conditions, the plume appears as a jagged rectangle before settling into a rectangular shape comparable to underexpanded cases for other geometries. The addition of scarfing also introduced differences in static pressure at the nozzle exit plane, influencing plume development and secondary flow characteristics. The degree of bifurcation lessens and the jet potential core length increases as the conditions move from overexpanded to underexpanded, which was expected.