Papers On Navy C-P Propeller Program And Spray Patterns Of Jet Thrusters Discussed At Joint SNAME Chesapeake/ASNE Meeting
The Chesapeake Section of The Society of Naval Architects and Marine Engineers and the Flagship Section of The American Society of Naval Engineers held a joint meeting recently at the Officers Club of the Bethesda Naval Medical Center. The meeting featured the presentation of two papers — one on the U.S. Navy controllable-pitch propeller program, and the other a student paper on spray patterns produced by jet thrusters.
The presentation of papers followed a social hour and dinner attended by about 150 members. The first part of the technical session was moderated by G. Boatwright of NAVSEC. The paper was entitled "U.S. Navy Controllable Pitch Propeller Programs," and was authored by Maurice Hauschildt, Richard Petros and Joseph Angelo. Mr. Hauschildt presented the paper, which described the U.S. Navy controllable- pitch propeller research and development program of the late 1960s and early 1970s. It discussed the failure of the USS Patterson (FF 1061) and the USS Barbey (FF-1088) research propellers, and the redesign and test of the Barbey propeller. It also discussed the Spruance (DD 963) propeller land-based tests and sea trials. The application of the data obtained from the R&D program to the DD 963, FFG 7 and future Navy designs was also discussed. A discussion period followed the presentation of the paper. The discussers included Capt. W. Wvatt, DD 963 Program Manager, R. Rockwell, DTNSRDC, C. Noonan, DTNSRDC, and D. Ridley, Bird-Johnson Co.
The second paper, "Spray Patterns Produced by Vertical Disk Thrusters Above Water Surfaces," was written by George E. Selecman and Alan N. Jennings, both of whom are students in the Aerospace and Ocean Engineering Department of Virginia Polytechnic Institute and State University. Jon Buck acted as moderator for this paper, which was presented by Mr. Selecman.
The paper presented an investigation of spray patterns produced by vertical disk thrusters over water surfaces. This work has application in understanding the spray which is likely to be produced by VTOL aircraft operating over water. The tests were conducted at DTNSRDC and at VPI. Qualitative analysis of test films from DTNSRDC led to experiments which showed a strong dependence of droplet size on Weber Number, Froude Number and the height of the disk thruster above the water surface. Dimensional analysis was used to devise a mathematical relationship between the most probable droplet size and the above mentioned parameters.