Editorial

Abstract

This volume contains 26 papers covering a wide range of flow problems, analysis and simulation methods and measurement techniques. Significant fraction of these papers deal with flows in complex geometries. Maier et al., in two papers, focus on the parameters influencing the flow at the inlet to an internal combustion engine. They measure the discharge coefficient and examine the occurrence of separation, reattachment, and heat transfer in the boundary layer on the valve seat using liquid crystal. The flow seems to be highly sensitive to small geometric changes. Consequently, in the second paper they systematically examine the effects of fillet radius, cone and seat angles. The latter two have significant effects on the valve performance. Radomsky and Thole report on 3-D velocity measurements and computations of the flow in a turbine vane passage. They show that substantial changes to the turbulent kinetic energy occur along the passage, and that these changes depend on the initial turbulence levels. Their RANS simulations are performed using different stress models with significant variations in results. Guillaume and LaRue measure the pressure and velocity spectra in the wakes of multiple plates aligned normal to the flow. The wakes vary between stable modes, flopping and quasi-stable behavior, depending on the ratio of plate spacing to plate thickness. A pair of papers by Huitenga and Mitra focus on improvements to the startup behavior of fluid coupling through modifications to runner geometry. Numerical simulations are used as guidance for determining the required modifications.