Sökning: "turbulence damping"

Visar resultat 6 - 10 av 19 avhandlingar innehållade orden turbulence damping.

1. 6. Computational Analysis of Heat Transfer and Fluid Flow with Relevance for IC-Engine Cooling

   Författare :Sassan Etemad; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Termisk teknik; termodynamik; turbulence models; Heat transfer; curved duct; secondary flow; IC-engine cooling; Gases; Thermal engineering; applied thermodynamics; Teknik; Technological sciences; plasma; Gaser; fluiddynamik; plasmas; fluid dynamics;

   Sammanfattning : Modern IC-engines produce more power per displaced volume and operate at higher combustion pressures and temperatures. In addition, engine structure materials such as aluminium and magnesium alloys, which are more sensitive to thermal loads, are more commonly used. LÄS MER

3. 7. Analysis of the Performance of Different V2F Turbulence Models in a Stator Vane Passage Flow

   Författare :Andreas Sveningsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat transfer; RANS; realizability; V2F; stator flow;

   Sammanfattning : When designing the cooling system of modern gas turbines it is important to be able to predict the heat transfer from the hot gas to the walls surrounding the gas path. One flow feature making this rather complicated is the presence of secondary, three-dimensional flow structures, often referred to as horse shoe vortices, which greatly enhance the rate of heat transfer to the endwall, especially in the leading edge region. LÄS MER

4. 8. Attenuation of boundary layer disturbances by means of streamwise vortices

   Författare :Sohrab Sattarzadeh Shirvan; Jens H. M. Fransson; Valery Chernoray; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer stability; Tollmien-Schlichting waves; oblique waves; transition to turbulence; streamwise vortices; miniature vortex generators; instability control; drag reduction;

   Sammanfattning : The stability of the boundary layer developed on a flat plate is studied in the presence of streamwise streaks where disturbances of different types are introduced in the wall-bounded shear layer. The experimental investigations are aimed at flow control by means of passively damping the energy growth of the disturbances in the streaky boundary layer and furthermore delay the onset of the transition in the streamwise direction. LÄS MER

5. 9. Experimental study on turbulent boundary-layer flows with wall transpiration

   Författare :Marco Ferro; Jens Fransson; Bengt Fallenius; Joseph Klewicki; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent boundary layer; boundary-layer suction; boundary-layer blowing; wall-bounded turbulent flows; self-sustained turbulence; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : Wall transpiration, in the form of wall-normal suction or blowing through a permeable wall, is a relatively simple and effective technique to control the behaviour of a boundary layer. For its potential applications for laminar-turbulent transition and separation delay (suction) or for turbulent drag reduction and thermal protection (blowing), wall transpiration has over the past decades been the topic of a significant amount of studies. LÄS MER

7. 10. Mechanistic Modeling of Annular Flows at Near-Dryout Conditions

   Författare :Wenyuan Fan; Henryk Anglart; Martin Rohde; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kärnenergiteknik; Nuclear Engineering;

   Sammanfattning : This work aims at advancing the modeling methodology for near-dryout annular flows using two different computational fluid dynamics (CFD) approaches. One is termed as the transported film approach, where the film flow is separately modeled by a simplified liquid film model and then coupled with the gas core simulation using various closures. LÄS MER