Sökning: "heat convection"

Visar resultat 11 - 15 av 109 avhandlingar innehållade orden heat convection.

1. 11. Pool Boiling on Structured Surfaces: Heat Transfer and Critical Heat Flux : Experiments and Mechanistic Modelling

   Författare :Zhen Cao; NanoLund: Centre for Nanoscience; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pool boiling; heat transfer; critical heat flux; bubble dynamics; surface modification;

   Sammanfattning : In this thesis, pool boiling heat transfer was experimentally studied on structured surfaces with dielectric liquids (HFE-7200, NOVEC-649, FC-72), organic liquids (Acetone, Pentane) and deionized water.In the first step, nanoparticle coatings on copper surfaces were prepared by an electrophoretic deposition method, with Cu-Zn nanoparticles (100 nm) and Cu nanoparticles (150 nm). LÄS MER

3. 12. A Study of Turbulent Natural Convection Boundary Layers Using Large-Eddy Simulation

   Författare :Darioush Gohari Barhaghi; Chalmers tekniska högskola; []
   Nyckelord :natural convection boundary layer; DNS; LES; radiation heat transfer; free convection; cavity; vertical cylinder;

   Sammanfattning : The structure of turbulent natural convection boundary layers in differentgeometries and the effect of the buoyancy on a mixed convection boundarylayer are investigated. These geometries comprise a vertical finitecylinder, a vertical infinite channel, a cavity and a vertical finite channel. LÄS MER

4. 13. Transport Coefficients during Drying of Solids containing Multicomponent Mixtures

   Författare :Rafael Gamero; Joaquín Martínez; Evangelos Tsotsas; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; capillary; conduction; convection; diffusion; evaporation; heat transfer; hydraulic conductivity; liquid film; liquid transport; mass transfer; Maxwell-Stefan diffusion coefficients; molar fluxes; phase equilibrium; temperature gradient; ternary mixture; thermodynamic factors; Chemical engineering; Kemiteknik;

   Sammanfattning : This study investigated the transport coefficients involved in mass and heat transfer during the drying of a porous solid partially saturated with multicomponent mixtures.  It included the coefficients governing liquid transport through the solid, the matrix of multicomponent diffusion coefficients in the liquid phase, and the effective thermal conductivity. LÄS MER

5. 14. Distribution of Ventilation Air and Heat by Buoyancy Forces inside Buildings : An Experimental Study

   Författare :Claes Blomqvist; Mats Sandberg; Per Heiselberg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; building ventilation; thermal forces; buoyancy; gravity currents; large openings; heating; air quality; forced convection; free convection; Building engineering; Byggnadsteknik;

   Sammanfattning : The main task of the ventilation system in a building is to maintain the air quality and (together with the heating or cooling system) the thermal climate at an acceptable level within the building. This means that a sufficient amount of ventilation air at the appropriate temperature and quality must be supplied to satisfy thermal comfort and air quality demands and that this air is distributed to the parts of the building where people reside. LÄS MER

7. 15. The Effective Convectivity Model for Simulation and Analysis of Melt Pool Heat Transfer in a Light Water Reactor Pressure Vessel Lower Head

   Författare :Chi Thanh Tran; Tomas Lefvert; Harri Tuomisto; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; light water reactor; hypothetical severe accident; accident progression; accident scenario; core melt pool; heat transfer; turbulent natural convection; heat transfer coefficient; phase change; mushy zone; crust; lower plenum; analytical model; effective convectivity model; CFD simulation; Thermal energy engineering; Termisk energiteknik;

   Sammanfattning : Severe accidents in a Light Water Reactor (LWR) have been a subject of intense research for the last three decades. The research in this area aims to reach understanding of the inherent physical phenomena and reduce the uncertainties in their quantification, with the ultimate goal of developing models that can be applied to safety analysis of nuclear reactors, and to evaluation of the proposed accident management schemes for mitigating the consequences of severe accidents. LÄS MER