This study was done to determine the influence of the needle displacement on the flow in a mono-hole Diesel injector. A simulation of an injection cycle was done with a numerical model. This model reproduces the physics of the flow, using URANS equations and a moving mesh that recreates the needle displacement. It was validated against experimental results, and with other criterion based on URANS modeling.
With this model, it’s possible to simulate a flow with different injection pressure, needle lift speed and fluid characteristics. A complete injection cycle was simulated using this model, with a constant injection pressure and needle speed. Flow coefficients are low for low lift, but they remain almost constant at high lift, although for the same lift, they are lower during the closing phase than during the opening phase.
An hysteresis phenomenon was discovered when studying the jet in the sac volume entrance, which in turn modifies the sac volume’s flow. The flow in the sac volume was then studied with a characterization method of vortex structures, which was developed in this thesis. Using this novel method gives us some vortex characterisation sush as vortex size, center of rotation, type (primary or secondary), and the rotation speed. The analysis of the sac volume flow with this method confirms the hysteresis discovered earlier.
| Date | 3 Mar 2016 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Louis Dufresne (Supervisor) & Patrice Seers (Co-supervisor) |
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Reveillon, D. (Author),
Dufresne (Supervisor) &
Seers (Co-supervisor),
3 Mar 2016Student thesis: Master's thesis › Master in Engineering: Mechanical Engineering