Avancerad sökning

Visar resultat 1 - 5 av 12 avhandlingar som matchar ovanstående sökkriterier.

1. 1. An Experimental Study of Fluid Dynamics and Mixing in Bubbly Gas-Liquid Flow Systems

   Författare :Jafar Sadegh Moghaddas; Livsmedelsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bubbly flow; PLIF; Two-phase flow; PIV; Gases; plasmas; Gaser; fluid dynamics; fluiddynamik; plasma; Mixing;

   Sammanfattning : In the present project, a new experimental method enabling Planar Laser-Induced Fluorescence (PLIF) measurements in bubbly gas-liquid flows is presented. Due to reflection and refraction of the laser light, the bubbles will cause an uneven and unknown distribution of light intensity in the measurement plane. 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. A Particle Image Velocimetry Study of Bubbly Gas-Liquid Flow

   Författare :Xiaoyun Tu; Livsmedelsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulent dispersion; Food and drink technology; Livsmedelsteknik; turbulence; Rushton turbine; stirred tank; slip velocity; bubbly gas liquid two-phase flow; coherent structure; CCD camera; PIV; POD;

   Sammanfattning : The aim of this work is to build a framework that can be used for characterizing the bubbly gas liquid turbulent flow in the stirred bioreactor tank. To this end we have developed and modified techniques with which to measure the velocity of both dispersed gas and carrier liquid phases by the optical measurement technique, a 2-CCD camera Particle Image Velocimetry (PIV) system; and to characterize the turbulence by the wavelets tool, Proper Orthogonal Decomposition (POD). LÄS MER

5. 4. Microfluidic Hydrodynamic of Gas-Liquid flow in Single Microchannel and Porous Media with Microchannel Network

   Författare :Shuo Yang; NanoLund: Centre for Nanoscience; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mass transfer; slug flow; porous media; interficial instability; fingering displacement;

   Sammanfattning : In this thesis, a microfluidics platform with high-speed imaging system was built to investigate gas-liquid flow in single microchannel and interfacial instability in porous media with microchannel network:The mass transfer of slug flow in the rectangular and square microchannels was experimentally studied by using water as liquid phase and CO2 as gas phase. Depending on flow rates, flow patterns including slug flow, bubbly flow, and annular flow were observed in rectangular and square microchannels. LÄS MER

7. 5. Numerical study of flow boiling in micro/mini channels

   Författare :Qingming Liu; Björn Palm; Satish Kandlikar; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical; boiling; micro channel; phase change.; Energiteknik; Energy Technology;

   Sammanfattning : Boiling phenomena in micro scale has emerged as an interesting topic due to its complexity and increasing usage in micro electronic and mechanical systems (MEMS). Experimental visualization has discovered five main flow regimes: nucleate boiling, isolated bubbles, confine bubbly flow, elongated bubbly (or slug) flow, and annular flow. LÄS MER