Use of visualization techniques to identify the transition to turbulence (critical Reynolds number) in a flow inside an annular space.

Selection of the geometry of the wires coil inserted, based on previous experiences.

Use of visualization techniques to identify the wires coil to induce turbulence with a lower mass flow rate.

Development of critical Reynolds number equations for fluid flow in an annulus with spiral wires inserted.

Determination of the pressure drop caused by wires coil inserted in an annular space for Reynolds numbers between 1500 and 5000.

Obtainment of friction coefficient equations for turbulent flow in an annular space where wires coil are inserted.