Sökning: "Free convection"

Visar resultat 1 - 5 av 29 avhandlingar innehållade orden Free convection.

1. 1. DNS and LES of Turbulent Natural Convection Boundary Layer

   Författare :Darioush Gohari Barhaghi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DNS; free convection; LES; natural convection boundary layer; vertical cylinder;

   Sammanfattning : Turbulent natural convection boundary layers possess some special characteristicscompared to the other boundary layers.In order to study this kind of boundary layer, two powerful numerical methods,Direct Numerical Simulation or DNS and Large Eddy Simulation or LES,are used. LÄS MER

3. 2. 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. 3. 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

5. 4. Energy Efficiency Improvements in Household Refrigeration Cooling Systems

   Författare :Erik Björk; Björn Palm; Claudio Melo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Household refrigerator; Domestic refrigerator; Free convection; Plate evaporator; Heat transfer; Flow boiling; Isobutane; R600a; Pressure drop; Two-phase; Cooling system; Charge inventory; Cyclic losses; Thermography;

   Sammanfattning : This thesis is based on eight articles all related to the characteristics of the cooling system and plate evaporator of a household refrigerator. Through these articles, knowledge is provided that can be used to increase the operational efficiency in household refrigeration. LÄS MER

7. 5. Thermocoagulation in Deep Brain Structures : Modelling, simulation and experimental study of radio-frequency lesioning

   Författare :Johannes Johansson; Karin Wårdel; Stefan Andersson-Engels; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Neurosurgery; Radiofrequency ablation; Finite element method; Blood perfusion; Cerebrospinal fluid; Free convection; Neurosurgery; Neurokirurgi;

   Sammanfattning : Radio-frequency (RF) lesioning is a method utilising high frequency currents for thermal coagulation of pathological tissue or signal pathways. The current is delivered from an electrode with a temperature sensor, permitting control of the current at a desired target temperature. In the brain RF-lesioning can e.g. LÄS MER