There are 4 nozzles on the AVS that can be changed to suit the particular application and Bit/BHA hydraulics design.
IDT have developed through Computer Flow Dynamics an inclined nozzle design that minimises erratic turbulence around the borehole wall. This ensures that all the flow is going “up” the hole in the direction of flow. Without inclined nozzles, some of the flow exiting the nozzle will try and go down the hole causing extreme turbulence which is not good for hole erosion in sensitive formations.
CFD of AVS flow in Splitflow position
CFD of AVS flow in Bypass position
The video shows an 8” AVS being surface tested. The blue collar around the inclined nozzles simulates the borehole wall. As can be seen 100% of the flow is directed in the direction of the annular flow up the well.