2.2 Momentum flow comparison Figure 2 shows the momentum flux carried by the mass fow passing between y=0... ye of the inviscid case. The viscous case capture height is increased by 8'so that the comparison is done at the same mass flows. In each case, the momentum flow can be considered to be the force acting on a barrier which arrests the flow velocity to zero momentum extractor (barrier) y y ye F Figure 2: Comparison of inviscid and viscous momentum flows, at the same mass flow dn pu2 dy= F= peuzye ye+6° Fy=udn "p2d=n2- (ue -u)oudy= Fr-Peu2e The viscous momentum flow is decreased by an amount equal to the momentum defect Peu20 2.3 Kinetic energy flow comparison Figure 3 shows the kinetic energy flux carried by the mass flow passing between y=0.ye of the inviscid case. The viscous case capture height is again increased by 8 so that the comparison is done at the same mass Rows. In each case, the kinetic energy flow can be considered to be the power generated on an array of perfect windmills which reversibly bring the flow velocity to zero. P adrn pudy= P= peudye e+6*1 udn= v+61e (2-2)mdy=B-2 The viscous kinetic energy flow is decreased by an amount equal to the kinetic energy defect dEuce