کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
761145 1462898 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A comprehensive study on the effect of cavitation on injection velocity in diesel nozzles
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی انرژی (عمومی)
پیش نمایش صفحه اول مقاله
A comprehensive study on the effect of cavitation on injection velocity in diesel nozzles
چکیده انگلیسی

Results when testing cavitating injection nozzles show a strong reduction in mass flow rate when cavitation appears (the flow is choked), while the momentum flux is reduced to a lesser extent, resulting in an increase in effective injection velocity. So as to better understand the origin of this increase in effective injection velocity, the basic equations for mass and momentum conservation were applied to an injection nozzle in simplified conditions.The study demonstrated that the increase in injection velocity provoked by cavitation is not a direct effect of the latter, but an indirect effect. In fact, the vapor appearance inside the injection hole produces a decrease in the viscosity of the fluid near the wall. This leads to lower momentum flux losses and to a change in the velocity profile, transforming it into a more “top hat” profile type. This change in the profile shape allows explaining why the momentum flux reduction is not so important compared to that of the mass flow rate, thus explaining why the effective injection velocity increases.


► Cavitation has an indirect effect on the effective injection velocity.
► Cavitation in the injector hole reduces locally the fluid viscosity.
► A lower viscosity leads to a more turbulent velocity profile.
► The more turbulent velocity profile justifies the increase in effective velocity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Energy Conversion and Management - Volume 64, December 2012, Pages 415–423
نویسندگان
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