... labrador canada towing tank conference st john full scale experience th 2004 high speed propeller august 6 fitzsimmon ship cavitation root cavitation vortex interaction The paper discusses some of the more complex cavitation structures that have been encountered in full-scale...

... Propeller tunnels fitted to high-speed yachts are becoming more prevalent. The advantages of reduced operating draft or the possibility of using larger propellers are attractive to the boat builder. This paper examines the effects of propeller tunnel applications on propeller cavitation...

... This paper provides results of full-scale video observations of underway cavitating propeller operation and corresponding vibration acceleration measurements taken in the stem region of the U.S. Coast Guard Seagoing Buoy Tender WLB 201 JUNIPER. Selected results are presented from two different...

.... The variability of these quantities are observed with PIV and the average quantities are compared between LDV and PIV. Developed cavitation is also examined for the leakage vortex. The implication of vortex variability on cavitation inception is discussed. plane cavitation variation core radius...

... An electrical impedance probe is used to study the properties of partial attached cavitation. The method uses a series of electrodes mounted flush to the surface of a cavitating hydrofoil to obtain ti.me-dependent information about the presence of liquid or vapor in the region of interest...

... Laminate construction technology is used to reduce the local angle of attack at the tip of an elliptic foil to delay the inception of tip vortex cavitation. As the angle of attack is increased on the foil, the increased lift causes the tip to flex in a direction that relieves the hydrodynamic...

... hydraulic jet pump cavitation waterjet propulsion figure 4 figure 2 cavitation inception inlet cavitation tunnel semi-flush inlet geometry stricker multiphase pump npsh inlet efficiency cavitate diameter thrust artificial lift system efficiency ingestion figure 1 model...

... Rudder surfaces can experience severe cavitation at high speeds or in hard turns resulting in excessive noise, vibration and erosion. Methods to improve surface ship rudder performance are being investigated at David Taylor Model Basin. As part of this project, effects of cavitation on rudder...

... A computational method (HPUF-3A) for the prediction of unsteady propeller blade sheet cavitation is applied to the analysis of supercavitating propellers in steady flow. The method is incorporating a vortex and source lattice scheme. To allow for the treatment of very long supercavities...

... This paper presents a method to design foil sections for marine propellers or hydrofoils using inviscid and boundary-layer theory. The current configuration allows a variety of goals and constraints including cavitation inception prediction, lift/drag maximization, and flow separation avoidance...

... tank cavitation cavitation channel bdwt multiphase flow mechanical engineering particle upstream oil & gas cavity blowdown experiment michigan hydrofoil mechanics california institute interaction figure 2 mlcc vacuum blowdown water tunnel laser cavitation inception contraction...

... tests show that the predicted increase in propulsive efficiency of 6-7% was achieved. The second application is a backfit to a high speed U.S. Coast Guard patrol boat. The purpose of this design is to eliminate severe cavitation erosion near the root of the existing propeller. A small span asymmetric...

... Several experiments performed by Ceccio and Brennen ( 1991, 1989) and Kumar and Brennen 1992, 1991) have closely examined the interaction between individual cavitation bubbles and the boundary layer, as well as statistical properties of the acoustical signals produced by the bubble collapse...

... A propeller design procedure incorporating new propeller blade sections has been developed to improve propeller cavitation inception. Two dimensional foil design procedures of Shen and Eppler provide geometry for a specified blade pressure distribution. Advanced propeller lifting surface design...

... Selective injection of a drag-reducing polymer solution into the tip vortex region of the blades of an 11.5 inch diameter propeller is seen to be effective in significantly delaying tip vortex cavitation. For well positioned injection ports, the cavitation number at inception was decreased...

... A supercavitating hydrofoil experiment is performed at the MIT Variable Pressure water tunnel, at several angles of attack and cavitation numbers. The velocity is measured on a rectangular contour surrounding the foil and cavity, and the results are compared to those from an analysis method...

... The tip vortex roll-up process from an elliptic wing was experimentally investigated. Cavitation provided an excellent method for visualizing the mechanism of vortex roll-up. The velocity profiles of the non-cavitating vortex were first obtained with a laser Doppler velocimeter. The measured...

... In order to investigate the character of cavitation inception from rotating rods, a series of experiments were performed in the 5000x450x450 mm test section of the University of Tokyo Propeller Cavitation Tunnel. This paper presents a summary of the experimental design, a comparison...

... cavitation A DESIGN METHOD AND AN APPLICATION FOR CONTRARO TATING PROPELLERS Benjamin Y.-H. Chen and Arthur M. Reed David Taylor Research Center, Bethesda, MD 20084, U. S. A. ABSTRACT A design methodology for contrarotating propellers bas been developed based on rational hydromechanics. Three fundamental...

... Propeller viewing trials are a necessary adjunct to towing tank and cavitation tunnel tests, if a full assessment of propeller performance is to be made. Unfortunately, viewing trials are rare because of the expense and disruption caused by the installation of propeller viewing ports...