Sökning: "Björn Palm"

Visar resultat 6 - 10 av 38 avhandlingar innehållade orden Björn Palm.

1. 6. Phase Change Phenomena During Fluid Flow in Microchannels

   Författare :Rashid Ali; Björn E Palm; Gian Piero Celata; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microchannels; Boiling; Heat Transfer; Thermal energy engineering; Termisk energiteknik; SRA - Energy; SRA - Energi;

   Sammanfattning : Phase change phenomena of a fluid flowing in a micro channel may be exploited to make the heat exchangers more compact and energy efficient. Compact heat exchangers offer several advantages such as light weight, low cost, energy efficiency, capability of removing high heat fluxes and charge reduction are a few to mention. LÄS MER

3. 7. Experimental and numerical study of the thermal and hydraulic effect of EMC screens in radio base stations : detailed and compact models

   Författare :Raúl Antón Remírez; Björn Palm; Masud Behnia; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sub-rack; perforated plate; air cooling; 90 degrees turn; flow deistribution; CFD; measurement; Mechanical energy engineering; Mekanisk energiteknik;

   Sammanfattning : Today’s telecommunication cabinets use Electro Magnetic Compliance (EMC) screens in order to reduce electromagnetic noise that can cause some miss functions in electronic equipment. Many radio base stations (RBSs) use a 90-degree building architecture: the flow inlet is perpendicular to the EMC screen, which creates a complex flow, with a 90-degree air turn, expansions, compressions, perforated plates and PCBs. LÄS MER

4. 8. Flow boiling heat transfer, pressure drop and dryout characteristics of low GWP refrigerants in a vertical mini-channel

   Författare :Zahid Anwar; Björn Palm; Rahmatollah Khodabandeh; Maria Fernandino; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mini micro-channels; R1234yf; R152a; R600a; R134a; Boiling heat transfer; Pressure drop; Dryout; Correlation;

   Sammanfattning : Two-phase heat transfer in mini/micro-channels is capable of meeting the high cooling demands of modern high heat flux applications. The phase change process ensures better temperature uniformity and control for local hot spots. Furthermore, these compact channels could be helpful in reducing the required charge and material inventories. LÄS MER

5. 9. Study into the Potential and Feasibility of a Standalone Solar-Wind Hybrid Electric Energy Supply System

   Författare :Getachew Bekele; Björn Palm; Philip Eames; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Speed; Sunshine Duration; Solar Radiation; Feasibility Study; Standalone System; Solar-Wind Hybrid; Thermal energy engineering; Termisk energiteknik;

   Sammanfattning : The tendency to use renewable energy resources has grown continuouslyover the past few decades, be it due to fear over warnings of globalwarming or because of the depletion and short life of fossil fuels or evenas a result of the interest which has developed among researchers doingscientific research into it. This work can be considered as joining any ofthese groups with an objective of giving electric light to the poorpopulation living in one of the poorest nations in the world. LÄS MER

7. 10. Single Phase Convective Heat Transfer with Nanofluids : An Experimental Approach

   Författare :Ehsan Bitaraf Hgahighi; Björn E. Palm; Elena V. Timofeeva; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanofluid; convective heat transfer; thermal conductivity; viscosity; heat transfer coefficient; performance; pumping power; Reynolds number; shelf stability;

   Sammanfattning : Nanofluids (NFs) are engineered colloids of nanoparticles (NPs) dispersed homogenously within base fluids (BFs). Due to the presence of NPs, the thermophysical and transport properties of BFs are subject to change. LÄS MER