Sökning: "wall roughness"
Visar resultat 1 - 5 av 39 avhandlingar innehållade orden wall roughness.
1. Homogenization of some new mathematical models in lubrication theory
Sammanfattning : We consider mathematical modeling of thin film flow between two rough surfaces which are in relative motion. For example such flows take place in different kinds of bearings and gears when a lubricant is used to reduce friction and wear between the surfaces. LÄS MER
2. Stability analysis and transition prediction of wall-bounded flows
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
3. Measurements and Prediction of Friction Drag of Rough Surfaces
Sammanfattning : Owing to the increased sea transportation of goods, the environmental impacts of this activity are becoming more and more important, since a ship experiences resistance that directly affects its performance and fuel consumption. The growth of marine organisms (fouling) on ship hulls increases the roughness of the hull surface, which in turn causes a rise in ship resistance with a consequent increase in fuel consumption and greenhouse emissions of up to 40%. LÄS MER
4. Receptivity of Boundary-Layer Flows over Flat and Curved Walls
Sammanfattning : Direct numerical simulations of the receptivity and instability of boundary layers on flat and curved surfaces are herein reported. Various flow models are considered with the aim to capture aspects of flows over straight and swept wings such as wall curvature, pressure variations, leading-edge effects, streamline curvature and crossflow. LÄS MER
5. Air-pocket transport in conjunction with bottom-outlet conduits for dams
Sammanfattning : Undesired air entrainment in bottom outlet conduits of dams may cause pressure transients, leading to conduit vibrations, blowback, discharge pulsation and even cavitation, and jeopardize the operational safety. Due to design limitations or construction costs, it is impossible to create an air free environment in a pressurized pipe. LÄS MER