Hydraulic Resistance and Flow Pattern at Design and Off Design Flow Rates Among Axial Flow Machines

In an axial flow machine, fluids flow condition, that is flow pattern in a rotating flow passage changes its form and magnitude by the hydraulic resistance to the fluid flow in flow passage. Effect of centrifugal force becomes stronger with the increase of hydraulic resistance, and the flow rate becomes smaller. And, in the comparison of fluids flow condition among different axial flow machines, if the efficiency at an equivalent flow rate differ one another, then on the favorable machine in efficiency grade, the effect of centrifugal force to the fluids flow pattern, formed in the flow passage, appears much obviously. With the decrease in flow rate this tendency becomes stronger as much the difference of efficiency grade becomes larger. All these relations may be held among axial flow machines, regardless to operating condition whichever they are operated at design or off design condition.