**(31)**

An inviscid flow is the flow of an ideal fluid assumed to have no viscosity. The flow of fluids with low values of viscosity can not be applied close to the fluid boundary where the boundary layers have a significant role. If we consider the boundary layers as the Lean Six Sigma areas where the diverse functions meet, we can determine that only low turbulence is beneficial in creating an appropriate and controlled flow since speed will increase once the pressure decreases or the fluid potential energy decreases. Bernoulli's principle states also that if a small volume of fluid is flowing horizontally from a region of high pressure to a region of low pressure, then there is more pressure behind than in the front.