1 the tests were conducted in 6 inch ld steel pipe it has been determined through previous testing that the mixer performs similarly at different flow rates provided the flow is turbulent u2014 thus only one water flow rate was tested 360 gpm at ambient pressure and temperature a uniform velocity inlet was imposed at the model inlet which was placed 5 pipe diameters upstream of the mixer inlet with a tracer concentration of 0 a uniform static pressure boundary condition was imposed at the model outlet which was placed 10 pipe diameters downstream of the mixer inlet such that the impact of the mixer could be documented as a function of downstream distance on all surfaces no slip impermeable adiabatic wall boundary conditions were applied with roughness heights set to 0 00015 ft as appropriate for steel pipe to measure mixing a 2 solution 7 2 gpm of a tracer fluid with properties equal to that of water was injected equally into two opposing u215c u2033 schedule 40 injection nozzles directly upstream of the mixer inlet the injection nozzles protruded 1 inch into the pipe or u2159 of the pipe diameter or the height of the mixing tabs the mixing of the solution was then monitored at 1 pipe diameter i e 6 inch intervals downstream the goal of the mixer is to achieve a uniform concentration of the injected material in as short a downstream distance as possible with.