Advanced models of fuel droplet heating and evaporation

The fabrication, materials, properties and applications of microstructured polymer optical fibers are reviewed. Microstructured polymer optical fibers formed the basis of extensive work on the physics of microstructured fibers, and an outline of the contribution to the wider field of microstructured fibers is also presented.

Microstructured Polymer Optical Fibers

We report a low-loss, low-cost high-sensitivity all-fiber strain and temperature sensor based on mode interference in graded-index multimode fibers. Blueshifts with strain and temperature sensitivities of 18.6 pm/microstrain and 58.5 pm/ degrees C have been observed. Experimental results show that smaller core diameter graded-index fibers display greater strain-induced peak wavelength shifts than larger core diameter fibers.

/pdf/low-cost-high-sensitivity-strain-and-temperature-sensing-3c3n4dbyu5.pdf

Low-Cost High-Sensitivity Strain and Temperature Sensing Using Graded-Index Multimode Fibers

In response to recent advances in numerical heat transfer research, the K-8 Committee of Theory and Fundamental Research of the ASME Heat Transfer Division has sponsored a symposium on the subject at the 1990 AIAA/ASME Thermophysics and Heat Transfer Conference in Seattle, Washington. This symposium volume contains the papers presented in three technical sessions. Works dealing with both the methodology and the results of numerical solutions of heat transfer problems are included in this volume. A large number of excellent manuscripts were submitted by researchers from this country and abroad. The papers collected here provide a representative cross section of current contributions to numerical methods in heat transfer.

Numerical heat transfer

https://www.staff.ul.ie/mitchells/Mitchell_AMC09.pdf

Finite-difference methods with increased accuracy and correct initialization for one-dimensional Stefan problems

Finite difference solution of one-dimensional Stefan problem with periodic boundary conditions

Using the power flow equation, we have examined the mode coupling caused by intrinsic perturbation effects of the step index plastic optical fiber. A numerical solution has been obtained by the explicit finite difference method. Results show the state of mode coupling along the fiber. They indicate that the equilibrium mode distribution is achieved at much shorter lengths compared to the case with glass fibers.

Investigation of mode coupling in step index plastic optical fibers using the power flow equation

The variable space grid method based on finite differences is applied to the one-dimensional Stefan problem with time-dependent boundary conditions describing the solidification/melting process. The temperature distribution, the position of the moving boundary and its velocity are evaluated in terms of finite differences. It is found that the computational results obtained by the variable space grid method exhibit good agreement with the exact solution. Also the present results for temperature distribution are found to be more accurate compared to those obtained previously by the variable time step method.

Numerical solution of Stefan problem with time-dependent boundary conditions by variable space grid method

Finite difference solution of the one-dimensional advection–diffusion equation with variable coefficients in semi-infinite media

The numerical solution of the complete power flow equation is reported and employed to investigate the state of mode coupling along a step-index plastic optical fiber. This solution is based on the explicit finite-difference method and, in contrast to earlier solutions, does not neglect absorption and scattering loss. It is the only solution that can accommodate any input condition throughout the entire range of feasible input angles without the need for restriction to those angles that are sufficiently far away from critical. Our results for the field patterns at different locations along one type of fiber are in agreement with reported measurements earlier. Furthermore, the length of fiber required for achieving a steady-state mode distribution matches the analytical solution that is available for such distribution as a special case. Mode coupling in plastic fibers is known to affect fiber-optic power delivery, data transmission, and sensing systems.

Svetislav Savović

Papers

Finite difference solution of one-dimensional Stefan problem with periodic boundary conditions

Investigation of mode coupling in step index plastic optical fibers using the power flow equation

Numerical solution of Stefan problem with time-dependent boundary conditions by variable space grid method

Finite difference solution of the one-dimensional advection–diffusion equation with variable coefficients in semi-infinite media

Numerical solution of the power flow equation in step-index plastic optical fibers