Sökning: "wobbling"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet wobbling.

1. 1. Numerical Analysis of Cavitation-Induced Erosion in High-Pressure Fuel Injectors: under static and dynamic lift conditions

   Författare :Mehmet Özgünoglu; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; Cavitation Erosion; Fuel Injector; Wobbling;

   Sammanfattning : Fuel injection systems are crucial for all modern combustion engines. These systems often operate under very high pressures to ensure fast spray breakup for optimal fuel air mixing leading to efficient combustion in order to meet strict emission standards. LÄS MER

3. 2. Models for Rotating Nuclei - Cranking and Rotor + Particles Coupling

   Författare :Gillis Carlsson; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-spin masses; 58Ni; particle rotor model; 86Nb; 163Lu; wobbling; cranking;

   Sammanfattning : This dissertation investigates properties of rotating atomic nuclei. Studies are performed using the cranking model and in the particles + rotor model. Properties studied are energy spectra and electromagnetic transition probabilities. LÄS MER

4. 3. Human Postures and Movements analysed through Constrained Optimization

   Författare :Robert Pettersson; Anders Eriksson; Elena Gutierrez-Farewik; Hans Berg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multibody system; optimal control; trajectory optimization; long jump; posture; Other engineering mechanics; Övrig teknisk mekanik;

   Sammanfattning : Constrained optimization is used to derive human postures and movements. In the first study a static 3D model with 30 muscle groups is used to analyse postures. The activation levels of these muscles are minimized in order to represent the individual's choice of posture. LÄS MER

5. 4. Snowmobile, motorcycle and moose-car accidents : aspects on injury control

   Författare :Ulf Björnstig; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Injury; accident; prevention; snowmobile; motorcycle; moose-car collision;

   Sammanfattning : Injuries related to snowmobiles, motorcycles and moose-car collisions have increased. The aim of the present thesis was to analyse mechanisms and consequences in fatal and non-fatal accidents of these types, and to penetrate possible preventive measures.SnowmobilesThe median age of the injured was 30 and of the killed 32, males pre­dominating. LÄS MER

7. 5. Numerical modeling of deforming bubble transport related to cavitating hydraulic turbines

   Författare :Daniel Lörstad; Institutionen för energivetenskaper; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gases; fluid dynamics; plasmas; Gaser; fluiddynamik; plasma; Energy research; Energiforskning; Direction Averaged Curvature DAC ; Direction Averaged Normal DAN ; Volume of Solid VOS ; Volume of Fluid VOF ; Lagrangian Particle Tracking LPT ; Large Eddy Simulation LES ; bubble; multiphase; turbulent flows; CFD; hydro-turbine;

   Sammanfattning : Cavitation is a problem in many hydroelectric power plants since it can cause adverse effects on performance and damage to nearby solid surfaces. The concerns of this thesis are the numerical aspects of flow simulations in cavitating hydraulic turbines which contain several difficulties: turbulent and complex flows, steady and moving parts of the geometry, bubble transport and cavitation development. LÄS MER