An Experimental Study of Velocity and Reynolds Stress Distributions in a Production Engine Inlet Port Under Steady Flow Conditions. 900058

Laser-Doppler anemometry was used to investigate steady flows in a helical port from a production engine. To enable optical access to all parts of the port and cylinder, the working fluid was a mixture of liquids with a refractive index identical to that of the acrylic material used for the test section. Measurements were made of the three mean velocity components and the corresponding turbulence levels and Reynolds stresses for four valve lifts. The discharge coefficient of the port was also measured.

Detailed mean flow measurements are presented for valve lifts of 6 and 9 mm, and less extensive data for lifts of 3 and 12 mm. There was little variation of the flow with valve lift in the upstream part of the port. The flow pattern in the vicinity of the valve and inside the cylinder did however vary with lift. There was evidence of some counter-swirl generated at the port exit. The swirl pattern inside the cylinder was dominated by a double rotation at the two lower lifts and a single rotation at the higher lifts. Results obtained at Reynolds numbers of 34,500 and 38,600 showed little difference in the flow patterns with flow rate through the port. For comparison, some measurements were made at certain locations in the cylinder with air flowing through the test section and matching Reynolds numbers to the liquid flow. There was agreement between both mean and r.m.s. velocities. Turbulent shear stress distributions are presented which show a complex variation throughout the port and cylinder. The measurements are in suitable form for use in the development and assessment of numerical calculations of the flows.