Evaluation of cavitation erosion of a propeller blade surface made of composite materials

Object and purpose of research. This paper discusses cavitation erosion on propeller blades. The purpose of this work is to review and analyse modern studies on cavitation erosion, as well as to apply these research results for better under-standing of cavitation damage risk on full-scale propellers. Materials and methods. The paper reviews recent studies on cavitation erosion, as well as the author’s own findings in cavitation erosion on full-scale steel propellers, analyzing the energy needed to create cavitation damage of recorded size. This energy was calculated as per the model based on the results of metallurgical studies discussing the effect of shot blasting upon steel properties. Comparison of these results with those obtained as per classic formulae for the collapse energy of cavita-tion bubble made it possible to estimate the conditions of cavitation erosion on propeller blades. Main results. The review of recent studies on cavitation erosion has shown that current progress in the technologies of experimental studies and computer-based simulations made it possible to considerably improve the knowledge about cavitation erosion process as compared to the level of the 20th century. This review shows that cavitation erosion studies followed three practically independent paths: experimental studies and computer-based simulation of flow around propeller blades with locali-zation of peaks for one or several criteria reflecting the intensity of cavitation energy fluctuations; the studies intended to esti-mate the pressure exerted by collapsing cavitation bubbles and emerging cumulative jets; and finally, the studies on the proper-ties of materials affected by cumulative jets and collapsing bubbles. At this point, it would be practicable to merge these three paths using the results of full-scale cavitation erosion analysis for propellers. KSRC findings in cavitation damage of full-scale steel propeller has shown that cavitation damage recorded in these studies might occur due to a certain combination between the required energy, bubble-blade interaction pressure and the size of affect-ed area on steel blade surface, and this combination, in its turn, might take place when cavitation bubbles consisting of vapour fraction with partial air content hit the blade surface and collapse. Conclusion. This paper shows the capabilities of modern research methods in obtaining new data on the inception mecha-nism of cavitation erosion. Still, to develop the methods for prediction of cavitation erosion (in particular, on propellers), it is necessary to merge the results obtained in different branches of cavitation studies. The basis for this merging could become a power-based analysis of cavitation processes, with help of the cavitation erosion model suggested in this paper and based on the similarity between cavitation erosion and shot-blasting.

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Frequency-domain analysis of fluctuating pressure on a pusher propeller blade surface

Journal of Aircraft ◽

10.2514/3.46453 ◽

1994 ◽

Vol 31 (1) ◽

pp. 42-48 ◽

Cited By ~ 5

Author(s):

Saeed Farokhi ◽

Ray Taghavi ◽

Kyle K. Wetzel

Keyword(s):

Frequency Domain ◽

Domain Analysis ◽

Frequency Domain Analysis ◽

Blade Surface ◽

Propeller Blade ◽

Fluctuating Pressure

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Analysis of the Geometry of Dents on a Propeller Blade Surface during Cavitation Wear

Journal of Friction and Wear ◽

10.3103/s1068366621010116 ◽

2021 ◽

Vol 42 (1) ◽

pp. 17-22

Author(s):

Y. N. Tsvetkov ◽

E. O. Gorbachenko ◽

Ya. O. Fiaktistov

Keyword(s):

Blade Surface ◽

Propeller Blade ◽

Cavitation Wear

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Specification of Acceptable Blade Porosity for Cavitation Performance of Marine Propellers

Volume 1: Fora, Parts A, B, C, and D ◽

10.1115/fedsm2003-45317 ◽

2003 ◽

Author(s):

David R. Stinebring ◽

William A. Straka ◽

W. R. Hall

Keyword(s):

Blade Surface ◽

Propeller Blade ◽

Cavitation Inception ◽

Local Boundary ◽

Marine Propellers ◽

Surface Pressure Distribution ◽

Cavitation Performance ◽

Penn State ◽

Propeller Blades ◽

Made In

The issues of cavitation inception for porosity for cast propeller blades are addressed. Desinent cavitation measurements were made in the ARL Penn State 48-inch diameter water tunnel for a series of holes machined into inserts mounted in the tunnel test section. The data were compared to previous measurements with slots and isolated roughnesses. A design exercise is presented for a generic propeller blade to specify “acceptable” blade porosity for a given cavitation inception goal. The application to the blade accounts for the spanwise velocity distribution, local blade surface pressure distribution, local boundary layer thickness, and porosity size. The final result is a mapping of ranges in acceptable porosity for locations on the blade.

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Cavitation Erosion Behavior on Thin Films of Polymer Blends Deposited Over Bronze Surfaces

Materiale Plastice ◽

10.37358/mp.18.3.5014 ◽

2018 ◽

Vol 55 (3) ◽

pp. 286-290

Author(s):

Ilare Bordeasu ◽

Adrian Circiumaru ◽

Mircea O. Popoviciu ◽

Iosif Lazar ◽

Rodica Badarau ◽

...

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Chemical Engineering ◽

Cavitation Erosion ◽

Physical And Mechanical Properties ◽

Polymeric Composite ◽

Repair Work ◽

Hydraulic Machines ◽

Industrial Use ◽

Reduced Adherence

The composite materials with polymeric matrix represent a great realization of chemical engineering. Their applications in all the industrial fields are dictated by their chemical, physical and mechanical properties. In the last 50 years the polymeric composite materials received a large use in the protection and repair work of the surfaces in contact with fluid currents of various natures. The scientific researches followed by the industrial use, show that the polymere films with certain composition and properties have an excellent behavior to chemical, abrasive and cavitation erosions. Because the most stressed machine details subjected to cavitation erosions are the blades, runners and impellers of hydraulic machines as well as the ship propellers, researchers are looking for the best polymers to increase the running time, or for the use in covering the zones with shallow erosions, during the repair work. In this direction is oriented also the present research, performed in the Cavitation Laboratory of the Timisoara Polytechnic University. The obtained cavitation erosion for specimens covered with different polymere films is compared with those realized in identical conditions, but for specimens without protection films. The results show that the films assure some increase in the resistance to cavitation erosion but the tested polymer layers have reduced adherence on the metal surface.

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Marine Propeller Geometric Models for NC Machining Efficiency and Accuracy

Journal of Ship Production ◽

10.5957/jsp.2001.17.2.97 ◽

2001 ◽

Vol 17 (02) ◽

pp. 97-102

Author(s):

Hsing-Chia Kuo ◽

Wei-Yuan Dzan

Keyword(s):

Differential Geometry ◽

Numerical Analysis ◽

Geometric Model ◽

Nc Machining ◽

Machining Efficiency ◽

Pressure Side ◽

Marine Propeller ◽

Blade Surface ◽

Propeller Blade ◽

Constant Pitch

Via the theories of computational geometry and differential geometry, the equation of the pressure side of a propeller blade with a constant pitch is presented. The model for defining maximal admissible ball-end cutter radius used in the NC machining of propeller blade surface is deduced. The odels for numerical analysis and for calculation of step lengths and path intervals are also provided. Besides, the related geometric model for calculating the actual maximal error by using the envelope surface of the cutter is presented. Finally, the feasibility and reliability of the proposed models and methods are verified by an example. It is also verified that the proposed method provides improved machining efficiency and accuracy relative to many other common contemporary methods.

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Flow Around the Revolving Propeller Blades in Low Reynolds Number Field

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2007-37102 ◽

2007 ◽

Author(s):

Nobuyuki Arai ◽

Hironori Yoshida ◽

Katsumi Hiraoka

Keyword(s):

Reynolds Number ◽

Wind Tunnel ◽

Number Field ◽

Wind Tunnel Testing ◽

Edge Region ◽

Blade Surface ◽

Propeller Blade ◽

Trailing Edge ◽

Propulsion Efficiency ◽

Propeller Blades

By studying the flow around the revolving propeller blades, an improvement of the propulsion efficiency can be found. We made the propeller blade optimized to get good propulsion efficiency by the Adkins & Liebeck’s propeller theory in low Reynolds number field. We call this blade “Prop00”. In order to investigate the flow around the propeller blades, distributions of pressure on the surface of the revolving propeller blade in some pitch angles were measured by wind tunnel testing. For Prop00, it was observed that the contour lines of Cp are dense near the trailing edge of blade’s tip. And it is thought that the separation may exist around the tip of blade. In order to compare the flow characteristics and to get the hint of improvement of the shape of the propeller blades, three different shape types of propeller blades, rectangle, trapezoid, and inverted trapezoid, were made. We call these blades “Prop01”, “Prop02”, and “Prop03”, respectively. According to the pressure distribution, it’s necessary to improve the shape of the propeller which suppresses the effect by a separation to improve the propulsion efficiency more. We took some photographs of tufts on the revolving blades with stroboscope to investigate vectors of the flow on the blade surface. These photographs are taken under identical conditions of the direct pressure measurement. It was observed that tufts tend to bent to the outer side direction by centrifugal force. However, differences on tufts bending were observed in the regions of the leading and the trailing edges at same radius. The tufts at the trailing edge region more bent to the tip of blade than that at leading edge region. Then, it is thought that separation and crossflow on the blade surface exist. We thought that the stability of the flow around the trailing edge is lost by the separation and the boundary layer transition. Furthermore, universal CFD software is used to study the improvement of the propeller performance. By using FLUENT 6 as universal CFD software, the result of CFD was compared with the result of wind tunnel testing.

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