Browsing by Author "Henriksson, Antti"

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  • Biopohjaisten pyrolyysiöljyjen tuotanto ja käyttö
    (2021-05-24) Henriksson, Antti
     Kemiantekniikan korkeakoulu | Bachelor's thesis
  • CFD-simulation of hydrogen jet fires using Fire Dynamics Simulator
    (2024-10-31) Henriksson, Antti
     School of Chemical Engineering | Master's thesis
    This thesis will govern the use of Fire Dynamics Simulator (FDS) in order to simulate under-expanded hydrogen jet fires using Lagrangian particles. Accurate simulation of large scale hydrogen jet fires utilizing FDS has been relatively unresearched topic. The objective of the thesis was to explore and validate use of FDS for simulation of large scale hydrogen jet flames, using previous experimental research on the topic. Simulations were conducted using test data from previous researches by Schefer and Ekoto as a base for comparison. One of the biggest challenges in simulating large, under-expanded jet flames is the requirement for extremely fine grid size. Large under-expanded jet flames create expansion effects that require significant time to simulate. In this thesis, these highly time-consuming calculations were not performed; instead, Lagrangian particles were used as sources of mass and momentum. The spray simulation results were validated against Schefer’s and Ekoto’s previous results for vertical and horizontal jet flames. When comparing experimented results with the simulated ones, it was observed that these jets could be simulated with good overall accuracy. A 10 cm grid was feasible for this kind of simulation, though the Lagrangian particles still required a long computing time. There were a lot of parameters that needed to be carefully evaluated to simulate these jet fires accurately, as this approach is relatively new. All in all further research involving complex geometries and much smaller grid sizes at the foot of the flame should be done in order to further validate the use of these simulations. FDS development team should also consider the possibility of adding official graphics processing unit (GPU) offloading for parallel computing, as this could potentially speed up the simulations of these jet fires significantly. As a result of this thesis, a new Eulerian-Lagrangian model was developed for hydrogen jet fire simulations.
  • Determination of the flow properties of microfibrillated suspensions
    (2012) Henriksson, Antti
     School of Chemical Engineering | Master's thesis
  • Finnish shares and their foreign demand: a study on factors affecting foreign investors' selection of shares
    (1990) Henriksson, Antti
     School of Business | Master's thesis
  • Tulosvertailua eri raaka-aineiden ja olosuhteiden välillä laimeahappohydrolyysissä
    (2009) Henriksson, Antti
     Kemian ja materiaalitieteiden tiedekunta | Bachelor's thesis