The main objective of this project is the thermal and fluid-dynamic analysis of phenomena in moist air environments: convective and diffusive transport in laminar and turbulent flows, stream mixing with supersaturation effects (fog), frost formation over cold surfaces, defrosting. The proposed methodology is based on a combination of the most advanced numerical tools for the thermal and fluid-dynamic analysis (CFD&HT) and a detailed experimental analysis to determine empirical coefficients that are mandatory in order to extend the capabilities and utility of the numerical tools. This empirism is a key factor in situations where the computational effort is boundless or where the involved phenomena imply certain parametrization (e.g. frost grain size/type, surface contact angle/adherence). Referring to simulation tools, the work will be centred on the integration of the LES models developed by the Research Group (spectro-consistent discretization, regularization models) with phenomenological aspects in scientific-technical interest around the management, generation and destruction of water vapor (moisture). With management we conceive the mixing and homogeneizing processes of air streams at different conditions, where is very important a correct description of the convective and diffusive water vapor transport. By generation we talk about the evaporation processes from wet/frosted surfaces (defrosting) or products with water content (vegetables, meat, etc.), which will imply a redefinition of adequate boundary conditions. In relation to frost formation or condensation phenomena the boundary conditions will be redefined through moving boundaries or the models should be modified to consider the fraction of water/frost contained in each control volume. The obtained numerical tool will be strategic for the combined analysis of such type of phenomena, being them critical in a great variety of future applications. The experimental plan is to complement the simulations with the necessary empirical information, and to compare/validate the implemented mathematical models where no other benchmark cases are available. The concept is to develop fundamental experiments, centred on simple geometries which allow for a clear characterization of the empirical parameter or the phenomena to be validated. The intention is to generate a systematic approach for future changes in geometry or conditions (e.g. other surfaces in frost formation). The proposed project is well within the basic research line of the Research Group: ‘Numerical simulation and experimental validation of heat and mass transfer phenomena. Application to the design of thermal systems and equipment’ (UPC research line 33220405).
Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2008-2011
Proyectos de Investigación Fundamental
Proyectos de investigación fundamental no orientada
Proyectos de investigación fundamental no orientada. Àrea de Energías convencionales alternativas
Gobierno De España. Ministerio De Economía Y Competitividad, Mineco