Sökning: "heat flow"

Visar resultat 1 - 5 av 648 avhandlingar innehållade orden heat flow.

1. 1. Water and Heat Transport in Road Structures : Development of Mechanistic Models

   Författare :Klas Hansson; Lars-Christer Lundin; Kurt Roth; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrology; Water flow; Heat flow; Unsaturated flow; Freeze-thaw; Numerical models; Uncertainty analysis; Sensitivity analysis; Roads; Overland flow; Flow patterns; TDR; Water content reflectometer; Calibration; Fractures; Hydrologi; Hydrology; Hydrologi;

   Sammanfattning : The coupled transport of water and heat, involving freezing and thawing, in the road structure and its immediate environment is important to consider for optimal design and maintenance of roads and when assessing solute transport, of e.g. de-icing salt, from roads. LÄS MER

3. 2. Flow Boiling Heat Transfer in Single Vertical Channels of Small Diameter

   Författare :Claudi Martin Callizo; Björn Palm; Predrag Hrnjak; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microchannel; heat exchanger; heat transfer; flow boiling; flow patterns; onset of nucleate boiling; dryout; critical heat flux; Mechanical and thermal engineering; Mekanisk och termisk energiteknik;

   Sammanfattning : Microchannel heat exchangers present many advantages, such as reduced size, high thermal efficiency and low fluid inventory; and are increasingly being used for heat transfer in a wide variety of applications including heat pumps, automotive air conditioners and for cooling of electronics.However, the fundamentals of fluid flow and heat transfer in microscalegeometries are not yet fully understood. LÄS MER

4. 3. Experimental Heat Transfer, pressure drop, and Flow Visualization of R-134a in Vertical Mini/Micro Tubes

   Författare :Wahib Owhaib; Björn Palm; Tassos Karayiannis; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Minichannel; microchannel; heat transfer; pressure drop; single-phase; two-phase; flow boiling; flow visualization; dry out; bubble behavior; flow pattern.; Mechanical energy engineering; Mekanisk energiteknik;

   Sammanfattning : For the application of minichannel heat exchangers, it is necessary to have accurate design tools for predicting heat transfer and pressure drop. Until recently, this type of heat exchangers was not well studied, and in the scientific literature there were large discrepancies between results reported by different investigators. LÄS MER

5. 4. Experimentella studier av värmeflöden och värmelagring i ett bebott flerbostadshus

   Författare :Lars Stenlund; Gunnar Bäckström; Olov Sandberg; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Energy balance; heat storage; heat flow; night setback; buildings; time constants;

   Sammanfattning : The study is experimentally inclined, with a high target precision for performance measurement. A comprehensive programme of measurements was carried out in a two-storey building, having a massive structure and dating from 1970. Measurements were made continuously during the heating season from a total of about 70 points. LÄS MER

7. 5. Heat Flow in Building Components, Experiment and Analysis

   Författare :Petter Wallentén; Institutioner vid LTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; radiation exchange; longwave; shortwave; transient; frequency analysis; finite difference; measurements; wall; window; heat transfer coefficient; convective; full scale; natural climate; in situ; counter flow insulation; heat transfer; dynamic insulation; temperature; building; solar radiation; window model; Building construction; Byggnadsteknik;

   Sammanfattning : Three building components exposed to natural climate were studied: a dynamic insulation in the ceiling of a house, an outer wall and one window in the same wall. The term dynamic insulation implies that part of the inlet or exhaust air passes through the insulation of a house. LÄS MER