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Purpose - This paper aims to develop and describe an improved process for determining the rate of heat generation in living tissue. Design/methodology/approach - Previous work by the authors on solving the bioheat equation has been updated to include a new localized meshless method which will create a more robust and computationally efficient technique. Inclusion of this technique will allow for the solution of more complex and realistic geometries, which are typical of living tissue. Additionally, the unknown heat generation rates are found through genetic algorithm optimization. Findings - The localized technique showed superior accuracy and significant savings in memory and processor time. The computational efficiency of the newly proposed meshless solver allows the optimization process to be carried to a higher level, leading to more accurate solutions for the inverse technique. Several example cases are presented to demonstrate these conclusions. Research limitations/implications - This work includes only 2D development of the approach, while any realistic modeling for patient-specific cases would be inherently 3D. The extension to 3D, as well as studies to improve the technique by decreasing the sensitivity to measurement noise and to incorporate non-invasive measurement positioning, are under way. Practical implications - As medical imaging continuously improves, such techniques may prove useful in patient diagonosis, as heat generation can be correlated to the presence of tumors, infections, or other conditions. Originality/value - This paper describes a new application of meshless methods. Such methods are becoming attractive due to their decreased pre-processing requirements, especially for problems involving complex geometries (such as patient specific tissues), as well as optimization problems, where geometries may be constantly changing. [ABSTRACT FROM AUTHOR]

Purpose - This paper seeks to discuss a mechanistic modeling concept for local phenomena governing two- and multi-phase flows and heat transfer. Design/methodology/approach - An overview is given of selected issues concerning the formulation of multidimensional models of two-phase flow and heat transfer. A complete computational multiphase fluid dynamics (CMFD) model of two-phase flow is presented, including local constitutive models applicable to two-phase flows in heated channels. Results are shown of model testing and validation. Findings - It has been demonstrated that the overall model is capable of capturing various local flow and heat transfer phenomena in general, and the onset of temperature excursion (CHF) in low quality forced-convection boiling, in particular. Research limitations/implications - Whereas the multiphase model formulation is applicable to a large class of problems, geometries and operating conditions, the closure laws and results are focused on forced-convection boiling in heated channels. Practical implications - The proposed approach can be used to predict multidimensional velocity field and phase distribution in two-phase flow devices and components used in thermal power plants, nuclear power plants and chemical processing plants. Originality/value - A complete mechanistic multidimensional model of forced-convection boiling in heated channels is given. The potential of a CMFD approach is demonstrated to perform virtual experiments that can be used in system design and optimization, and in safety analysis. [ABSTRACT FROM AUTHOR]