Influence of jet inlet conditions on time-average behavior of transverse jets

Dynamics and dispersion mechanisms in transverse jets are partially controlled by jet-exit conditions that are intimately linked to the coupling between issuing jet and crossflow. Accurate knowledge of this coupling is crucial to plan repeatable and effective experiments, perform accurate computations, and design dispersion control devices. A simplified geometry is focused on, representing a plenum/nozzle and a wind/water tunnel, to characterize the time-averaged extent of the coupling between the jet and crossflow and its effect on jet penetration, with specific emphasis on the following: 1) The relative importance of simulating/neglecting the coupling between jet and crossflow within the nozzle/plenum (pipe) is established to reproduce the jet penetration observed experimentally. 2) The distance down the pipe is characterized to determine how far down the presence of the crossflow modifies the flow with respect to the case of a jet issuing in a quiescent fluid. 3) Variations calculated in jet penetration are quantified when different boundary conditions are used to simulate the jet. 4) The effect of different crossflow velocities at jet exit on simulated jet penetration is evaluated. Results discussed may provide a guideline for future computational investigations on transverse jets and a useful reference to understand the discrepancies observed between experimental and numerical results.