A ray-tracing method is presented for numerically determining radiative view factors in complex three-dimensional geometries. This uses a set of “primitive” shapes to approximate the required geometry together with Monte Carlo simulation track fate randomized rays leaving each surface. View were calculated an operational fiber drawing furnace using both numerical integration and methods. Calculated factor profiles essentially identical above ray density 105 per unit area. Run times...

Microstructured optical fibers (MOFs) achieve their desired performance via a pattern of holes that run along the length fiber. Varying hole allows variety effects to be produced. However, original within preform may not accurately transferred finished fiber due combined impact material properties and drawing conditions experienced during fabrication. In this two-part paper, processes MOFs having arbitrary cross-sectional structures will analyzed for case Newtonian materials. Part I presents...

In drawing microstructured optical fibers (MOFs), the cross-sectional hole structure, including holes' relative size and shape, in a finished fiber drawn down from preform can be different that designed due to combined effects of draw tension surface tension. As result, fiber's properties initial design significantly altered. order find means minimizing or exploiting deformation so MOFs with desirable functionality fabricated, underlying mechanism is analyzed by numerically investigating...

An optical fiber taper is fabricated by heating and stretching a fiber. The resulting shape important as it strongly affects performance. In this paper, the tapering process of solid modeled analyzed under several conditions. material assumed to be non-Newtonian inelastic type. results show that for given profile, tapered independent properties conditions applied at ends, section uniform waist can formed long extensional deformation rate in zone position-independent. Different shapes tapers...

By combining theoretical, numerical, and experimental analyses, this paper examines the continuous draw process that underpins fabrication of microstructured optical fibers (MOFs) with aim quantifying impact material properties drawing conditions on hole structure in finished fiber. First, by treating as a steady-state isothermal extensional flow Newtonian material, three-dimensional (3-D) modeling clearly demonstrates how combination force effects can lead to dramatic deformation neck-down...

Considerable recent research has focused on the ability of microstructured fibers to exhibit diverse optical functionalities. However, accurately preserving structure imposed at preform stage after drawing it down fiber, while avoiding Rayleigh–Plateau style instabilities, proven be a major fabrication challenge. This modeling/analytical study was carried out in support an experimental program into possible options for various and considers generic case nonisothermal capillary fiber. Model...

Plasmonic metamaterials are composites containing metal structures imbedded within a dielectric matrix. Their nanoscale structure gives them optical properties that can be nonexistent in naturally occurring materials. However, the requirement for subwavelength creates difficulties when fiber drawing technology is used to fabricate such due Plateau-Rayleigh instability effects. This paper addresses issues by combining classic linear stability analysis with scaling considerations of concentric...

Summary In numerically simulating heat and mass transport processes in an unconfined domain involving synthetic open (inflow and/or outflow) boundaries, how to properly specify flow conditions at these boundaries can become a challenging issue. this work, within the context of pressure‐based finite volume method under unstructured grid, solution procedure without need for explicit specification profiles any when incompressible fluid is proposed examined. Within methodology, boundary not...