AN EXPERIMENT ON ENLARGING STEADY WORKING RANGE OF SKEWED-SWEPT ROTATING BLADES

An experimental investigation on enlarging the steady working range of skewed-swept rotating blades has been completed.Two types of fan were compared,a fan with conventional (radial) rotating blades and other with the skewed-swept blades.One comparative group was carried out on the conditions of same rotating speed and geometrical parameters but median chord of the skewed-swept rotating was increased about 20 4%,another was carried out at same peak pressure ratio and flow rate.The results of aerodynamic-aeroacoustic performance testing of the groups show not only a noise reduction about 2-4 dB(A) overall,and an increase of aerodynamic efficiency for the skewed-swept blad,but also a great enlargement of steady working range (one group about 21%,other more than 22%).On the basis of the experimental results,the mechanism of the enlargement of steady working range for skewed-swpet rotating blades was analyzed.