Fifty Years of Jet in Cross Flow Research

The jet in cross flow (JICF) is a basic flowfield which is relevant to a wide variety of applications which are described to provide context for JICF investigations. Material consistent with the scope of topics presented at the 72nd AGARD Fluid Dynamics Panel Meeting and Symposium on Computational and Experimental Assessment of Jets in Cross Flow on 19-22 April 1993 in Winchester, U.K. is summarized. The JICF research was divided into three time periods: (1) early research - up to 1970, (2) research during the 1970's, and (3) research since 1980. The following areas of experimental activity are discussed; the definition of an effective correlation parameter; the jet flowfield including the jet trajectories, cross-section shape, and jet induced pressures; the effects of jet deflection angle, nozzle shape, pressure ratio, velocity decay, and temperature; and the effect of confined flowfield, ground effects, multiple jets, and adjacent surface geometry. In addition, computational methods are discussed including both potential flow based methods, some with empirical and semi-analytical extensions, and Navier-Stokes based computational fluid dynamics (CFD) investigations. Currently modern CFD methods have been able to compute many of the mean flow characteristics of the JICF. Existing CFD methods have not resolved the separated flow region in the near wake of the jet exit. There is also a need for high quality, extensive experimental data which will enable the verification of current and future CFD results and to define unsteady flow characteristics.