Sökning: "droplet velocities"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden droplet velocities.

1. 1. Droplet Velocities in a Liquid Spray

   Författare :Andreas Cronhjort; KTH; []
   Nyckelord :Liquid spray; diesel spray; droplet velocities; droplet sizes; sprayvisualization; sliced spray; particle image velocimetry; spectrum; cepstrum; cross-correlation; auto-correlation;

   Sammanfattning : A method to look into a dense liquid spray has beenevaluated. The spray was mechanically sliced to remove theobscuring parts of it, thus gaining optical access to theinternal regions and thereby allowing for visualization ofpreviously unavailable parts of the spray. LÄS MER

3. 2. Numerical approaches to droplet growth in atmospheric turbulence

   Författare :Xiang-Yu Li; Axel Brandenburg; Gunilla Svensson; Luca Brandt; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; turbulence; coagulation; condensation; rain formation; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

   Sammanfattning : The bottleneck problem of cloud droplet growth is one of the most challenging problems in cloud physics. Cloud droplet growth is neither dominated by con-densation nor gravitational collision in the size range of 15–40 μm in radius. Turbulence-generated collision has been thought to be the mechanism to bridge the size gap, i.e. LÄS MER

4. 3. A Numerical and Experimental Investigation of the Internal Flow of a Freezing Water Droplet

   Författare :Linn Karlsson; Alexander Kaplan; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : The overarching aim of this work is to study the freezing process of a single water droplet freezing on a cold surface, which is an interesting and important phenomenon with possible applications in many areas. Understanding the freezing process of a single water droplet is for example an important step when preventing unwanted icing, e.g. LÄS MER

5. 4. Large-Eddy Simulation of Gasoline Fuel Spray Injection at Ultra-High Injection Pressures

   Författare :Sandip Wadekar; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; High pressure fuel injection; spray-wall interaction; spray-turbulence interaction; GDI engine; Spray modeling;

   Sammanfattning : Gasoline direct injection is a state-of-the-art technique that reduces hydrocarbon and particulate emissions. However, further improvement is needed to meet current as well as future emission regulations. LÄS MER

7. 5. Ultra-High Pressure Spray for Gasoline Direct Injection Engines

   Författare :Akichika Yamaguchi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; particulate emission.; gasoline direct injection engine; gasoline spray; high pressure spray; GDI;

   Sammanfattning : There is an increasingly urgent need for vehicle manufacturers to reduce emissions from passenger vehicles to protect the environment and comply with increasingly stringent emissions standards such as Euro 6d, which came into force in January 2021, and Euro 7, which will probably come into force around 2025. Current emissions standards limit passenger vehicles' particulate number emissions to at most 6*10^{11} [#/km], making it necessary to find ways of reducing the engine-out particulate emissions of gasoline direct injection engines to meet this requirement. LÄS MER