Scaling of Trajectories of Elliptic Jets in Crossflow

Abstract

A jet in crossflow is a fundamental flow phenomenon that is important to a variety of engineering applications, such as aerodynamic flow control, film cooling of turbines and combustors, and jet-mixing enhancements, just to name a few. Over the past 60 years, numerous experimental and computational studies have been conducted on various aspects of the flowfield with much of the attention focused on the large-scale flow structure development, jet trajectories, scalar-mixing and transport properties, and other associated flow phenomena [1–27]. Although the scaling of the trajectories of a circular jet in crossflow has been studied for many years, there is still no generally accepted scaling parameter for the jet trajectory. The scaling parameters that have been proposed by researchers include d (by Kamotani and Greber [1], andChassaing et al. [2]), rd (byPratte andBaines [3]) and rd (byKeffer andBaines [4]), where r is the velocity ratio defined as jet velocity/crossflow velocity. Pratte and Baines [3], who derived the rd-scaling-based dimensional analysis, argued that the jet trajectory should not be normalized by d or rd, and went on to propose the power-law formulation