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Effect of Shroud and Orientation Angles of Inlet Valve on Flow Characteristic Through Helical–Spiral Inlet Port in Diesel Engine

Research Authors
A. Abd El-Sabor Mohamed, Saleh Abo-Elfadl and Abd El-Moneim M. Nassib
Research Year
2017
Research Journal
Journal of Engineering for Gas Turbines and Power
Research Publisher
ASME
Research Vol
Vol. 139 -issue 10
Research Rank
1
Research_Pages
NULL
Research Website
https://gasturbinespower.asmedigitalcollection.asme.org/article.aspx?articleID=2617143
Research Abstract

The in-cylinder airflow motion is an important factor that severely affects combustion efficiency and emissions in diesel engines. It is greatly affected by the inlet port and valve geometries. A diesel engine cylinder with a helical–spiral inlet port is used in this study. An ordinary inlet valve and shrouded inlet valve having different shroud and orientation angles are used to study the shroud effect on the swirl and tumble motion inside the engine cylinder. Four shroud angles of 90 deg, 120 deg, 150 deg, and 180 deg are used. With each shroud angle, four orientation angles of 0 deg, 30 deg, 60 deg, and 90 deg are also used. Three-dimensional simulation model using the shear stress transport (SST) k–ω model is used for simulating air flow through the inlet port, inlet valve, and engine cylinder during both the intake and compression strokes. The results showed that increasing the valve shroud angle increases the swirl, and the maximum increase occurs at a valve shroud angle of 180 deg and orientation angle of 0 deg with a value of 80% with respect to the ordinary valve. But it decreases the volumetric efficiency, and the maximum decrement occurs at valve shroud of 180 deg and orientation angle of 90 deg with a value of 5.98%. Variations of the shroud and orientation angles have very small effect on the tumble inside the engine cylinder.