Numerical Modelling of Fuel Sprays

Research output: ThesisDoctoral Thesis (compilation)

Abstract

The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction beween the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. The use of numerical calculations is an important tool to better understand these complex interacting phenomena.

This thesis reports on the numerical modelling of fuel sprays in non-reacting cases using an own developed spray module. The spray module uses the stochastic parcel method to represent the spray. The module was made in such manner that it could by coupled with different gas flow solver. Results obtained from four different gas flow solver are presented in the thesis, including the use of two different kinds of turbulence models.

In the first part the spray module is coupled with a k-epsilon based 2-D cylindrical gas flow solver. A thorough sensitivity analysis was performed on the spray and gas flow solver parameters, such as grid size dependence and sensitivity to initial values of k-epsilon. The results of the spray module were also compared to results from other spray codes, e.g. the well known KIVA code.

In the second part of this thesis the spray was injected into a turbulent and fully developed crossflow studied. The spray module was attached to a LES (Large Eddy Simulation) based flow solvers enabling the study of the complex structures and time dependent phenomena involved in spray in crossflows. It was found that the spray performs an oscillatory motion and that the Strouhal number in the wake was about 0.1. Different spray breakup models were evaluated by comparing with experimental results.

Details

Authors
  • Christer Bergström
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Fluid Mechanics and Acoustics

Keywords

  • vibration and acoustic engineering, vacuum technology, hydraulics, Mechanical engineering, Gas turbine., Temperature fluctuations. Diesel engine, Counter rotating Vortex Pair, CVP, Large Eddy Simulation, Droplet Evaporation, Turbulent flows, LES, Spray, Modelling, Break-up, Maskinteknik, hydraulik, vakuumteknik, vibrationer, akustik, Carbochemistry, petrochemistry, fuels and explosives technology, Petrokemi, bränslen, sprängämnen
Original languageEnglish
QualificationDoctor
Awarding Institution
Supervisors/Assistant supervisor
  • [unknown], [unknown], Supervisor, External person
Award date1999 Jun 14
Publisher
  • LTH, Lund University
Publication statusPublished - 1999
Publication categoryResearch

Bibliographic note

Defence details Date: 1999-06-14 Time: 10:15 Place: Room M:B, Ole Römers väg 1, Lund External reviewer(s) Name: Cavalliere, Antonio Title: [unknown] Affiliation: Italien ---