Periodic single-blade loads on propellers in tangential and longitudinal wakes / by Robert J. Boswell, Stuart D. Jessup, Ki-Han Kim

Marine Propellers

“…There seems to be no obvious explanation for this contradictory behavior. Figure 16b, also from Boswell et al (1981), shows a similar correlation between theory and experiment for a circumferentially varying inflow generated by a screen. Here, all three theories considered agree well at the design advance coefficient of the propeller, but none follow the eXl~rimental trend at low advance coefficients.…”

“…The latter problem is not a concern if the nonuniform inflow is generated as a result of the inclination of the rotation axis relative to the flow direction. This is the case in Figure 16a, taken from Boswell et al (1981), which shows substantial disagreement between Tsakonas et al and Kerwin & Lee in the prediction of the once-per-revolution alternating thrust force on a single blade. Both theories underpredict the force compared with experimental results, although to varying degrees depending on the advance coefficient of the propeller.…”

Evaluation of Propeller Unsteady Force Codes for Noncavitating Conditions

“…The loads on a single blade were measured [1] at the NSWCCD tow tank on Carriage 2. The propeller was advancing in open water and was driven from downstream on an inclined shaft.…”

“…Previous validation studies [ 1,2,3] concluded that PUF-2 was the best code for calculating unsteady forces, and PUF-2 has been used extensively. However, new unsteady force codes are now available, and the new codes need to be evaluated.…”

A Study on Performance and Cavitation of Propellers for High Speed Crafts Including Effect of Boss

“…For the present study the vortex lattice method, hereafter termed as VLM, was chosen because it lends itself to the easiest adaptability for a particular propeller problem through required modifications in a relatively simple way. The VLM proposed by Kerwin( 1) is being increasingly used for propeller related studies (2,3,4,5,6) these days. In all these studies, however, it has been assumed that the boss has no significant influence on the propeller performance and thus can be ignored.…”