Optimization of Inlet Port Design in a Uniflow-Scavenged Engine Using a 3-D Turbulent Flow Code

Inlet port design has a great influence on swirl generation inside the engine cylinder. In this paper, two helical inlet ports having the same helix design were suggested. The first has an upper entrance, and the second has a side entrance. With the two ports, shrouded inlet valves having different conditions of shroud and orientation angles were used. Four shroud angles were used; they are 90 deg, 120 deg, 150 deg, and 180 deg. Also, four orientation angles were used; they are 0 deg, 30 deg, 60 deg, and 90 deg. Three-dimensional simulation model using the shear stress transport k–ω model was used for predicting the air flow characteristics through the inlet port and the engine cylinder in both intake and compression strokes. The results showed that the side entrance port produces swirl ratio higher than that of the upper entrance port by about 3.5%, while the volumetric efficiency is approximately the same for both ports. For both the ports, increasing the valve shroud angle increases the swirl ratio and reduces the volumetric efficiency. The maximum increments of swirl ratio relative to the ordinary valve case occur at valve conditions of 30–150 deg, 0–180 deg, and 30–180 deg. At these valve conditions, the swirl ratio values are 6.38, 6.72, and 6.95 at intake valve close (IVC) with percentage increments of 69.2%, 78.2%, and 84.4%, respectively. The corresponding values of the volumetric efficiency are 93.6, 92.5, and 91.2, respectively, with percentage decrements of 2.84%, 4%, and 5.7%, respectively.

Download Full-text

A Parametric Approach to Spark-Ignition Engine Inlet-Port Design

10.4271/1999-01-0555 ◽

1999 ◽

Cited By ~ 14

Author(s):

Hugh Blaxill ◽

Jonathan Downing ◽

Justin Seabrook ◽

Mike Fry

Keyword(s):

Spark Ignition ◽

Spark Ignition Engine ◽

Parametric Approach ◽

Inlet Port ◽

Port Design

Download Full-text

A Port in the Storm

Mechanical Engineering ◽

10.1115/1.1999-nov-5 ◽

1999 ◽

Vol 121 (11) ◽

pp. 78-79

Author(s):

Steve Pierson ◽

Steve Richardson

Keyword(s):

Fluid Dynamics ◽

Computer Simulation ◽

Design Process ◽

Fuel Economy ◽

High Accuracy ◽

Dramatic Improvement ◽

Inlet Port ◽

The Past ◽

Port Design ◽

Fuel Consumption And Emissions

Computer simulation of the inlet port is helping to provide improved fuel economy and emissions in up-coming Jaguar models. Jaguar engineers have long wanted to improve the inlet port design process by simulating flow in alternative inlet port designs. The engineers, however, experienced problems in modeling the complex internal contours of the inlet port and chamber. The dramatic improvement in modeling speed combined with the high accuracy of sin1.ulation has made it practical to integrate computational fluid dynamics into the inlet port and chamber design process. Jaguar engineers are now able to evaluate concept designs within one week compared to the month or more that was required in the past. Engineers have been able to make significant improvements in the performance of their most recent inlet port designs, increasing flow efficiency by an average of 10 percent, while maintaining turbulence at acceptable levels. These improvements will provide significant reductions in fuel consumption and emissions in future Jaguar engines.

Download Full-text