The overall performance of the blower is first presented for a series of values of blade stagger and ‘flap angle’ of the rotor row. The influence of gap is shown up by comparison amongst these results. Experiments were then carried out in which the gap was partially closed, and it is shown that the gap is least effective near the root section. These results were confirmed by inter-row traversing. Comparison of the tandem blade row with a single row of the same overall aspect ratio is presented and the improvements due to the tandem row are assessed.
