FormationFreeJet

formation of a free jet

Goals of this Unit:

Learn to use the Selection-feature in USER_common_variables.dat.

The fluid-mechanical problem: In this example, the fluid flows through a pipe and forms a free jet at the end of the pipe. The free jet hits an inclined plate. When such a steady cylindrical jet of water surrounded by air is impinged on an inclined flat rigid plate, the jet spreads as a sheet of water radially outward from the point of impact. Since we need a closed geometry, the plate and the cylindrical pipe is set up in the way as seen in Figure 1 below. The flow over the plate is shown in Figure 2. Here should be a picture

Figure 1: Free Jet Hitting the inclined plate

Using the selection criteria: In this example, the selection criteria is demonstrated using the ‘‘case’’ to choose whether to use a turbulence model or not. We provide the different choices for the ‘‘TurbulenceModel’’ in the solver section. The desired value is assigned to the alias ‘’TURB’’ initially as below.

begin_alias{} "TURB" = "OFF" # switch turbulence model on with "ON", switch it off with "OFF" end_alias

And the TurbulenceModel is chosen from the defined cases in solver section.

begin_alias{} begin_selection{"TURB"} case{"OFF"} "TurbulenceModel" = " " case{"ON"} "TurbulenceModel" = "TURBULENCE:k-epsilon" end_selection end_alias

Figure 2: Flow over the plate