Sökning: "isolated roughness"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden isolated roughness.

1. 1. Effects of free-stream turbulence and three-dimensional roughness on boundary layer transition

   Författare :Santhosh Babu Mamidala; Jens H. M. Fransson; Bengt E. G. Fallenius; Jonathan Morrison; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary-layer transition; intermittency; free-stream turbulence; electret microphones; isolated roughness; sinuous instability; varicose instability; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : External disturbances such as free-stream turbulence (FST), and isolated three-dimensional roughness are strong disturbance sources to the laminar boundary layers (BLs), which can lead to a rapid transition to turbulence. The transition process eventuates to increase in skin-friction coefficient and heat transfer rate and hence, both of the aforementioned disturbance sources have practical importance. LÄS MER

3. 2. Nanostructured materials isolated from bio-residues, and their characterization

   Författare :Martha Herrera Rodríguez; Henrikki Liimatainen; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Trä och bionanokompositer; Wood and Bionanocomposites;

   Sammanfattning : The use of natural components in nanocomposites has continuously increased, due to environmental problems that are growing day by day. The use of bio-residues from forest industries to develop new materials will not only alleviate ecological problems but also affect the economy of forest industries positively. LÄS MER

4. 3. On Surface Topography of Steel Sheet for Car Bodies

   Författare :Magnus Jonasson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; paint appearance; forming; steel sheet; bearing area; 3D surface roughness; area parameters; ball filter; friction; surface topography;

   Sammanfattning : This thesis is a contribution to the scientific area of surface topography on sheet metal surfaces. The studies are restricted to exploring the influence of the steel sheet,s surface topography on forming properties and on appearance after painting. LÄS MER

5. 4. Hydrodynamic lubrication of rough surfaces

   Författare :Fredrik Sahlin; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

   Sammanfattning : Interacting surfaces are frequently found in mechanical systems and components. A lubricant is often added between the surfaces to separate them from mechanical contact in order to increase life and performance of the contacting surfaces. In this work various aspects of hydrodynamic lubrication are investigated theoretically. LÄS MER

7. 5. Preparation and characterization of nanocellulose films and coatings from industrial bio-residues

   Författare :Martha Herrera; Per Stenius; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Trä och bionanokompositer; Wood and Bionanocomposites;

   Sammanfattning : The aim of this work has been to study cellulose nanocrystals (CNC) from bio-residues and their use as green coating materials. In the first part of this work, physical and chemical properties of different types of cellulose nanocrystals, from different raw material sources and different treatments were compared. LÄS MER