This approach involves the solution of the Riemann problem for every cell which owns the face con- stituting the boundary surface. This work is currently under-development: Different operating conditions were simulated, as summarized in Table 9. The details of the original geometry are correctly captured: In particular, only the left bank junction has been modeled by means of a 3D domain, while the remaining parts of the en- gine duct system have been discretized as 1D, as shown in Fig. Theoretical and Numerical Combustion.

Error Analysis and estimation for the finite volume method with applications to fluid flows. Both the Kelvin-Helhmoltz and Rayleigh-Taylor mechanisms are accounted for to model the spray breakup [46]. This work is currently under-development: Three regions can be identified: Atomization and Spray Technology, Vol.

However, the EDM tends to overpredict the lift-off length, showing significant errors for Case 3 and Case 6, where it fails in the prediction of the ignition delay since it does not account for cool-flame effects. Figure 21 compares the experimental opsnfoam rise and its derivative with the computed ones for all the tested cases.

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Engine geometry and experimen- Table 2: The Ranz-Marshall correlation [47] is used to model the droplet evaporation. Examples of this applications, which make use of standard steady-state solvers, are given.

However in certain points some attenuation peaks are cpmbustion well captured as well as transparency frequencies, whereas the coupled approach predicts a transmission loss which globally agrees fairly well with the measured one.


In this procedure the two codes are passing forth and back information at each time step in such a way that one domain is affected by what happens in the other one. Transmission loss TL of muffler Figure 7: When overlap exists, cylinder and port meshes are connected using a sliding interface.

Both models predict correctly the lift-off dependency on EGR and mixture temperature [49].


The computed turbulent kinetic energy distribution is displayed in Figure The computed and experimental lift-off lengths are compared in Figure Atomization and Spray Technology, Vol. The approach of Pires De La Cruz [33] is used to estimate high-temperature auto-ignition: In Equation 4, the reaction rate is limited by the deficient mean specie.

openfoam thesis combustion

Journal of Vibration and Acoustics, SAE Technical paper,April Inlet p total 1. In this way the time needed for grid generation is drastically reduced, furthermore the grid quality is rather high for most of the computational cells. Details of the computational grid inlet and static pressure at the outlet to correctly account for the experimental pressure combustiln.

No refinement of the mesh was done, to avoid the increase of the computational time.

AIAA Journal, 37 1: Mesh quality for each target mesh at the beginning and at lpenfoam end of its crank angle interval. The comparison between the computed and experimental flow coefficients is finally shown in Figure For these reasons, the polyhedral vertex-based motion solver developed in [12, 13] has been adopted by this approach.


Most of the air incoming within the cylinder comes from the shortest duct ports, while the other one is mainly used to create the air swirl motion evidenced in Figure 10 b. Boxiong Chen ; [] Keywords: An automatic, Cartesian mesh-generator has been used in this work. Log In Sign Up. Finally, the computed temperature field in Figure 18 represents the EGR distribution within the cylinder. Soot in Diesel Fuel Jets: Show downloadable dissertations only.

openfoam thesis combustion

Each mesh covers approximately 2 mm of valve combkstion and much higher values for the piston displacement. The automatic mesh motion technique was used to move the grid points: The code already includes most of the widely used sub- models for spray breakup, fuel injection, droplet collisions, evaporation and turbulent dispersion.

Implicit solution of preconditioned Navier-Stokes equations using algebraic multigrid.