Supersonic boundary-layer stability in a high-area-ratio nozzle
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Pauley, Laura L.↗
Engineering topics
Pauley, Laura L.
Publications and source records attributed to Pauley, Laura L..
A numerical investigation of supersonic nozzle boundary layer transition
The boundary layer stability within the high-area-ratio nozzle at NASA Lewis was tested at five chamber pressure conditions. For all nozzle conditions examined, Taylor-Goertler vortices grew more rapidly than Tollmien-Schlichting waves. The experimental heat flux was accurately predicted by a laminar boundary layer computation, thereby confirming the laminar nature of the nozzle boundary layer flow. When the chamber pressure was increased in a series of cases, the transition point occurred farther upstream. The number of vortices contained in the dominant instability increased with chamber pressure.
Pauley, Laura L.↗
A study of methods to investigate nozzle boundary layer transition
To further investigate nozzle flow, numerical computations are employed. The computations produce complete flow velocity and temperature fields within the nozzle. As a check, these results can be compared with experimental data at the wall. Once an accurate numerical scheme has been validated, it can be used as a design tool to predict the performance of other nozzle designs without the cost of experimental testing. Typically, the numerical analysis assumes either a laminar boundary layer or a fully turbulent boundary layer which is steady and two-dimensional. Boundary layer transition is not considered. Computing both the completely laminar boundary layer and the completely turbulent boundary layer conditions gives the minimum and maximum wall heat flux possible for a specified geometry. When the experimental heat flux measurements lie between these two values, the nature of the boundary layer is unknown. The boundary layer may have transitioned from laminar to turbulent; three-dimensional structures may be present in the boundary layer, or the inlet flow conditions may not be correctly specified in the computation.
Pauley, Laura L.↗