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Full-Text Articles in Engineering
Helical Models Of The Bidirectional Vortex In A Conical Geometry, Timothy Andrew Barber
Helical Models Of The Bidirectional Vortex In A Conical Geometry, Timothy Andrew Barber
Doctoral Dissertations
This dissertation represents the descriptive and analytical breakdown of two new fluid dynamics solutions for vortex motion. Both solutions model the bidirectional vortex within a conical geometry. The first explored solution satisfies a simple Beltramian characteristic, where the Lamb vector is identically zero. The second solution is of the generalized Beltramian type, which fulfills the condition that the curl of the Lamb vector is equal to zero. The two Beltramian solutions describe the axisymmetric, double helical motion often found in industrial cyclone separators. Other applications include cone-shaped, vortex-driven combustion chambers and the swirling flow through conical devices. Both solutions are …
On Compressible Gaseous Motions In Swirl Dominated Combustors, Brian A. Maicke
On Compressible Gaseous Motions In Swirl Dominated Combustors, Brian A. Maicke
Doctoral Dissertations
In this dissertation, a number of models are derived to describe swirling flows. Both generalized compressible Bragg-Hawthorne and vorticity-stream function frameworks are determined and left in a generic form suitable for describing a number of different scenarios. These systems are solved for the bidirectional vortex flowfield by means of a Rayleigh-Janzen perturbation, which expands the governing equations in terms of the Mach number squared. The resulting equations are solved to provide a semi-analytical solution after the evaluation of a handful of numerical integrals. These solutions further the understanding of compressible flow in swirl-combustors, as previous compressible studies are primarily experimental …
The Biglobal Instability Of The Bidirectional Vortex, Joshua Will Batterson
The Biglobal Instability Of The Bidirectional Vortex, Joshua Will Batterson
Doctoral Dissertations
State of the art research in hydrodynamic stability analysis has moved from classic one-dimensional methods such as the local nonparallel approach and the parabolized stability equations to two-dimensional, biglobal, methods. The paradigm shift toward two dimensional techniques with the ability to accommodate fully three-dimensional base flows is a necessary step toward modeling complex, multidimensional flowfields in modern propulsive applications. Here, we employ a two-dimensional spatial waveform with sinusoidal temporal dependence to reduce the three-dimensional linearized Navier-Stokes equations to their biglobal form. Addressing hydrodynamic stability in this way circumvents the restrictive parallel-flow assumption and admits boundary conditions in the streamwise direction. …