SAILWING WINDMILL CHARACTERISTICS AND RELATED TOPICS.

A NUMBER OF CENTER BODY RATIOS (BODY DIAMETER/ROTOR DIAMETER) HAVE BEEN TESTED IN THE PRINCETON 2' * 3' WIND TUNNEL AND REPORTED UPON.THE RESULTS OF ADDITIONAL WORK FURTHER LOOKING INTO AND CONFIRMING PREVIOUS TRENDS OF THE EFFECT OF THIS SENSITIVE GEOMETRIC PARAMETER ARE REPORTED HEREIN.A MOST IMPORTANT TESTING TECHNIQUE IS ALSO DISCUSSED IN DETAIL.THIS IS A METHOD OF EXPERIMENTALLY DETERMINING THE PERFORMANCE OF LARGE SCALE WINDMILL MODELS MOUNTED ON A MOVING VEHICLE.FINALLY, AS A RESULT OF THE WIND TUNNEL EXPERIMENTS, ANALYSIS, AND THE LARGE SCALE VEHICLE WORK, AN OPTIMIZATION OF A PARTICULAR ROTOR IS DESCRIBED IN DETAIL.ALSO DESCRIBED ARE THE RESULTS OF BLADE TWIST EXPERIMENTS AS A METHOD OF RPM CONTROL.BECAUSE THE WIND TUNNEL MODELS WERE NECESSARILY SMALL SCALE, RIGID ROTOR BLADES WERE USED; HOWEVER, THE LARGE SCALE ROTORS TESTED AND REPORTED UPON WERE OF THE PRINCETON SAILWING TYPE.BY MEANS OF DIMENSIONAL ANALYSIS AND BY EXPERIMENTS THE SIGNIFICANT TENSION COEFFICIENT FOR THE TRAILING EDGE CABLE OF THE SAILWING ROTOR HAS BEEN DETERMINED AND EVALUATED.THIS TENSION COEFFICIENT ENABLES THE DESIGN OF SUCH A ROTOR TO BE SUCH THAT THE LUFFING THRESHOLD CAN BE AVOIDED FOR ANY GIVEN SET OF CONDITIONS.(A)