Search for dissertations about: "fluid flow in tubes"

Showing result 1 - 5 of 21 swedish dissertations containing the words fluid flow in tubes.

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

   Author : Wahib Owhaib; Björn Palm; Tassos Karayiannis; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 2. Parameterisation and flow design optimisation of hydraulic turbine draft tubes

   Author : Daniel Marjavaara; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Abstract : In the present energy market, the demands of rehabilitation and modernisation of old constructions are increasing. Among the renewable energy resources, hydropower offers one of the highest potential for further improvements due to the fact that a great number of hydropower plants are ageing and that they are run at off-design conditions. READ MORE

5. 3. Analytical and Numerical Investigations of Steady and Unsteady Turbulent Swirling Flow in Diffusers

   Author : Walter Gyllenram; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; draft tube; diffuser; LES; vortex breakdown; turbulence; CFD; swirling flow;

   Abstract : Swirling flows are found in many technical applications, e.g. turbines, pumps, fans, compressors and combustors. The objective of the present work is to acquire an understanding of the physics of swirling flow in general and unsteady swirling flow in draft tubes of water turbines in particular. READ MORE

6. 4. Flow Boiling Heat Transfer in Single Vertical Channels of Small Diameter

   Author : Claudi Martin Callizo; Björn Palm; Predrag Hrnjak; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

7. 5. Phase Change Phenomena During Fluid Flow in Microchannels

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

   Abstract : 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. READ MORE