Author : Theodore Theodorsen
Publisher :
Page : 92 pages
File Size : 31,10 MB
Release : 1944
Category : Aerodynamics
ISBN :
Book Description
Summary: Values of the circulation function have been obtained for dual-rotating propellers. Numerical values are given for four-, eight-, and twelve-blade dual-rotating propellers and for advance ratios from 2 to about 6. In addition, the circulation function has been determined for single-rotating propellers for the higher values of the advance ratio. The mass coefficient, another quantity of significance in propeller theory, has been introduced. This mass coefficient, which is actually the mean value of the circulation coefficient, expresses the effective area of the column of the medium acted upon by the propeller in terms of the propeller-disk area. Values of the mass coefficient, which have been determined directly by special measurements and also by integration of the circulation function, are given for the four-, eight-, and twelve-blade dual-rotating propellers. The mass coefficient has also been determined for several cases of single-rotating propellers, partly for the purpose of comparing such experimental values with theoretical results in the known range of low advance ratios and partly to extend the results to include a range of high advance ratios. The effect of stationary countervanes on the mass coefficient has also been determined for several cases of practical interest.