Sökning: "flow rate"

Visar resultat 21 - 25 av 1128 avhandlingar innehållade orden flow rate.

1. 21. Vortices in turbulent curved pipe flow-rocking, rolling and pulsating motions

   Författare :Athanasia Kalpakli Vester; P. Henrik Alfredsson; Ramis Örlü; Nils Tillmark; Knud Meyer; KTH; []
   Nyckelord :Turbulence; curved pipes; swirling flow; pulsatile flow; time-resolved stereoscopic particle image velocimetry; hot-wire anemometry; proper orthogonal decomposition; turbocharger;

   Sammanfattning : This thesis is motivated by the necessity to understand the flow structure of turbulent flows in bends encountered in many technical applications such as heat exchangers, nuclear reactors and internal combustion engines. Flows in bends are characterised by strong secondary motions in terms of counter-rotating vortices (Dean cells) set up by a centrifugal instability. LÄS MER

3. 22. Characterization of Chimney Flue Gas Flows : Flow Rate Measurements with Averaging Pitot Probes

   Författare :Janne Paavilainen; Chris Bales; Jan-Olof Dalenbäck; Lennart Gustavsson; Högskolan Dalarna; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flue gas; measurement; characterization; averaging Pitot tube; SolNET;

   Sammanfattning : Performance testing methods of boilers in transient operating conditions (start, stop and combustion power modulation sequences) need the combustion rate quantified to allow for the emissions to be quantified. One way of quantifying the combustion rate of a boiler during transient operating conditions is by measuring the flue gas flow rate. LÄS MER

4. 23. Stress, Flow and Particle Transport in Rock Fractures

   Författare :Tomofumi Koyama; Lanru Jing; Marc Boulon; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Numerical simulation; laboratory experiments; rock fracture; coupled stress-flow-tracer test; shear displacement; fluid flow; particle transport; finite element method FEM ; particle tracking method; Navier-Stokes equation; Reynolds equation; streamline velocity dispersion.; Geoengineering; Geoteknik;

   Sammanfattning : The fluid flow and tracer transport in a single rock fracture during shear processes has been an important issue in rock mechanics and is investigated in this thesis using Finite Element Method (FEM) and streamline particle tracking method, considering evolutions of aperture and transmissivity with shear displacement histories under different normal stresses, based on laboratory tests. The distributions of fracture aperture and its evolution during shear were calculated from the initial aperture fields, based on the laser-scanned surface roughness features of replicas of rock fracture specimens, and shear dilations measured during the coupled shear-flow-tracer tests in laboratory performed using a newly developed testing apparatus in Nagasaki University, Nagasaki, Japan. LÄS MER

5. 24. Retinal glucose metabolism and blood flow : Effects of photic stimulation

   Författare :Lin Wang; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Physiology and anatomy; blood flow; darkness; flicker; glucose oxidation; glycolysis; lactate; light; nitric oxide; optic nerve; retina; Fysiologi och anatomi; Physiology and pharmacology; Fysiologi och farmakologi; Physiology; fysiologi;

   Sammanfattning : Retinal glucose metabolism was investigated under different light conditions in cats,pigs and rabbits. Glycolysis and glucose oxidation in the outer and inner parts of theretina were assessed by determining arteriovenous concentration differences foroxygen, glucose and lactate, as well as local blood flow. LÄS MER

7. 25. Flow and Mixing of Pulp Suspensions

   Författare :Johan Pettersson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; flow behaviour; boundary-layer; Medium Consistency MC ; mixing; yield stress; suspension; pulp; Laser Doppler Anemometry LDA ; turbulence; fibre;

   Sammanfattning : When producing pulp and paper, pulp suspensions are treated in a number of unit operations at medium consistency (MC) concentrations (3-15% by weight). Pulp suspensions at these concentrations behave as solids at low shear rates, but at sufficiently high shear rates they start to flow and can even be made to act as water. LÄS MER