1. L=65mm 1
2. At anyaxiallocation, thedifferencebetween the largestandthesmallestpeakfromthepotentialwakeofthe forwardbladeisameasureoftheinfluenceoftherearblade field. Iftherearbkdesaremoved,thesepeaksare.ofequal magnitude and the differencebetween them is zero. For example,thepeakvelocityinFig. 10forZ=45mm varies by about 5 Wsecforthatparticularrearbladelocation. If all possible rear blade positions are examined. onemay selectthemaximumdiffennceanduseitasanindicationof rearrotorinteractionwith forwardblade wakes. Figure 15 shows thevariationofthismeasureofintaactionwithaxial probeposition,Z. The.curveshowsthedecayof influence fromthe.rearrotoruponthewakesfromtheforwardblades. a? 6 - 5 - 4 - 3 - 2 - 1'1
3. Noise and performance of a counter-rotation propeller