Avancerad sökning

Hittade 4 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Durability of District Heating Pipes

   Författare :Stefan Forsaeus Nilsson; RISE; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reuse of excavated material; district heating pipe; moisture diffusion; pipe joint; stone indentation; polyurethane foam; polyethylene; district heat distribution; long-term strength; buried pipe;

   Sammanfattning : This thesis is focused on mechanical loads and moisture related problems with a potential to critically harm the functionality of pre-insulated district heating pipes and pipe joints. Directly buried pipeline bends are investigated with respect to limiting deformations from a thermally induced lateral displacement. LÄS MER

3. 2. Deformations and stresses in welded pipes : numerical and experimental investigation

   Författare :Lars Troive; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datorstödd maskinkonstruktion; Computer Aided Design;

   Sammanfattning : In this dissertation, deformations and stresses in welded pipes have been studied both numerically and experimentally. The aim of this work has been to investigate and verify finite element models for simulation of the fabrications of two types of pipe joints. LÄS MER

4. 3. Experimental study of passive scalar mixing in swirling jet flows

   Författare :Ramis Örlü; Henrik Alfredsson; Peter Johansson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; swirling jet; turbulence; passive scalar; mixing; hot-wire anemometry; cold-wire; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : Despite its importance in various industrial applications there is still a lack of experimental studies on the dynamic and thermal field of swirling jets in the near-field region. The present study is an attempt to close this lack and provide new insights on the effect of rotation on the turbulent mixing of a passive scalar, on turbulence (joint) statistics as well as the turbulence structure. LÄS MER

5. 4. Effects of boundary conditions and unsteadiness on draft tube flow

   Författare :Michel Cervantes; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : The present research focuses on flow properties of the elbow draft tube. This element has a major function in low head turbines, since up to half of the losses may arise there at part load. The use of computational fluid dynamic (CFD) to redisign a draft tube necessitates detailed knowledged of the boundary conditions. LÄS MER