Sökning: "wall-jet"

Visar resultat 6 - 10 av 19 avhandlingar innehållade ordet wall-jet.

1. 6. Numerical studies of transtion in wall-bounded flows

   Författare :Ori Levin; Dan Henningson; Nikolaus Adams; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer; suction; wall jet; streaks; waves; periodic disturbance; localized disturbance; turbulent spot; algebraic growth; exponential growth; stability; transition thresholds; transition prediction; PSE; DNS; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : Disturbances introduced in wall-bounded flows can grow and lead to transition from laminar to turbulent flow. In order to reduce losses or enhance mixing in energy systems, a fundamental understanding of the flow stability and transition mechanism is important. LÄS MER

3. 7. Stability analysis and transition prediction of wall-bounded flows

   Författare :Ori Levin; KTH; []
   Nyckelord :Boundary layer; wall jet; algebraic growth; exponential growth; lift-up effect; streamwise streaks; Tollmien-Schlichting waves; free-stream turbulence; roughness element; transition prediction; Parabolized Stability Equations; Direct Numerical S;

   Sammanfattning : Disturbances introduced in wall-bounded .ows can grow andlead to transition from laminar to turbulent .ow. In order toreduce losses or enhance mixing in energy systems, afundamental understanding of the . LÄS MER

4. 8. A Ventilation Strategy Based on Confluent Jets : An Experimental and Numerical Study

   Författare :Setareh Janbakhsh; Bahram Moshfegh; Alexander Zhivov; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple interacting jets; round jets; confluent jets; wall jet; ventilation strategy; air distribution system; air supply device; ventilation performance; thermal comfort; energy-saving potential; measurement; numerical predictions; RANS turbulence models; renormalization group RNG k– ε ; realizable Re k– ε ; and shear stress transport SST k– ω ;

   Sammanfattning : This study presents air distribution systems that are based on confluent jets; this system can be of interest for the establishment of indoor environments, to fulfill the goals of indoor climate and energy-efficient usage. The main objective of this study is to provide deeper understanding of the flow field development of a supply device that is designed based on wall confluent jets and to investigate the ventilation performance by experimental and numerical methods. LÄS MER

5. 9. Turbulent jets in confined spaces : application in mixing ventilation: experimental and numerical studies

   Författare :Taghi Karimipanah; Mats Sandberg; H. A. Awbi; Högskolan i Gävle; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulent; wall jet; impinging jet; free jet; confinement effect; pressure; throw; experimental; numerical; corner; momentum; mixing ventilation;

   Sammanfattning : The basis of mixing ventilation is the airflow supply to the room by means of jets initiatedfrom the ventilation diffusers. To avoid the draught problem, the design of mixing ventilationmakes uses the throw term, which is defined as the distance to the supply air terminal inwhich the jet centreline mean velocity is decreased to a given value. LÄS MER

7. 10. A study of turbulence and scalar mixing in a wall-jet using direct numerical simulation

   Författare :Daniel Ahlman; Arne V. Johansson; Lars-Erik Eriksson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningmekanik; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : Direct numerical simulation is used to study the dynamics and mixing in a turbulent plane wall-jet. The investigation is undertaken in order to extend the knowledge base of the influence of the wall on turbulent dynamics and mixing. The mixing statistics produced can also be used to evaluate and develop models for mixing and combustion. LÄS MER