Search Results

Computer simulations are compared with measurements of the three-dimensional, unsteady scavenging flows of a motored, crankcase-scavenged, two-stroke engine. Laser Doppler velocimetry measurements were made on a modified Suzuki DT-85 ported engine. Calculations were performed using KIVA-3, a computer program that efficiently solves the transfer and exhaust port flows along with those in the cylinder. Measured and computed cylinder pressures and velocities are compared. Pressures agree well over the cycle as do the velocities at the transfer port/cylinder interface. In-cylinder velocities differ in detail, but the tumbling motion in the cylinder is well replicated in a vertical plane passing through the cylinder axis.

Since its public release in 1985, the K1VA computer program has been used for the time dependent analysis of chemically reacting flows with sprays in two and three space dimensions. This paper describes some of the improvements to the original version that have been made since that time. The new code, called KIVA-II, is planned for public release in early 1988. KIVA-II improves the earlier version in the accuracy and efficiency of the computational procedure, the accuracy of the physics submodels, and in versatility and ease of use. Numerical improvements include the use of the ICE solution procedure in place of the acoustic subcycling method and the implementation of a quasi-second-order-accurate convection scheme. Major extensions to the physical submodels include the inclusion of an optional k-ε turbulence model, and several additions to the spray model. We illustrate some of the new capabilities by means of example solutions.