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Joseph Katz - One of the best experts on this subject based on the ideXlab platform.
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Effect of Gap Size on Tip Leakage Cavitation Inception, Associated Noise and Flow Structure
Journal of Fluids Engineering, 2002Co-Authors: Shridhar Gopalan, Joseph Katz, Henry L LiuAbstract:This paper focuses on the onset of tip-leakage Cavitation on a fixed hydrofoil. The objectives are to investigate the effect of gap size on the flow structure, conditions of Cavitation Inception, the associated bubble dynamics and Cavitation noise. The same hydrofoil with three tip gap sizes of 12%, 28%, and 52% of the maximum tip thickness are studied. Controlled Cavitation tests are performed after de-aerating the water in the tunnel and using electrolysis to generate Cavitation nuclei. The experiments consist of simultaneously detecting Cavitation Inception using a 2000 fps digital camera (visual) and two accelerometers (acoustic) mounted on the test section windows. To obtain the time-dependent noise spectra, portions of the signal containing Cavitation noise are analyzed using Hilbert-Huang transforms. Rates of Cavitation events as a function of the Cavitation index (σ) for the three gap sizes are also measured
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On the Flow Structure, Tip Leakage Cavitation Inception and Associated Noise
2001Co-Authors: Shridhar Gopalan, Henry L Liu, Joseph KatzAbstract:The objective of this study is to investigate the effect of gap size on the flow structure and on the Inception of tip leakage Cavitation. Controlled Cavitation tests were performed after de-aerating the water in the tunnel and using electrolysis to generate Cavitation nuclei. The experiments consisted of simultaneously detecting Cavitation Inception using a 2000fps digital camera (visual) and two accelerometers (“acoustic”) mounted on the test-section windows. Good agreement between these methods was achieved when the visual observations were performed carefully. Portions of the signal containing Cavitation noise were analyzed using Hilbert and Wavelet transforms. In order to obtain the time dependent spectra, rates of Cavitation events as a function of the Cavitation index (σ) for the 3 gap sizes (0.6, 1.4, 2.6mm) were measured. The observations clearly demonstrate that high amplitude noise spikes are generated when the bubbles are distorted and “shredded”—broken to several bubbles following their growth in the vortex core. Mere changes to bubble size and shape caused significantly lower noise. High resolution Particle Image Velocimetry (PIV) (a vector spacing of 180μm) was used to measure the flow, especially to capture the slender tip vortices where Cavitation Inception was observed. Seventy instantaneous realizations for the 0.6mm gap and 65 for the 1.4mm gap were analyzed to obtain distributions of circulation of the leakage vortex. PIV experiments for the 2.6mm gap are presently underway and only instantaneous samples are presented. The vortex core diameter was found to be 3–4 vector spacings. Minimum pressure coefficients in the cores of these vortices were estimated using a Rankine model. These coefficients showed a very good agreement with the measured Cavitation Inception indices.
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Numerical study of Cavitation Inception in the near field of an axisymmetric jet at high Reynolds number
Physics of Fluids, 2000Co-Authors: Stefano Cerutti, Omar M. Knio, Joseph KatzAbstract:Cavitation Inception in the near field of high Reynolds number axisymmetric jets is analyzed using a simplified computational model. The model combines a vorticity–stream-function finite-difference scheme for the simulation of the unsteady flow field with a simplified representation for microscopic bubbles that are injected at the jet inlet. The motion of the bubbles is tracked in a Lagrangian reference frame by integrating a semiempirical dynamical equation which accounts for pressure, drag, and lift forces. The likelihood of Cavitation Inception is estimated based on the distributions of pressure and microscopic bubbles. The computations are used to examine the role of jet slenderness ratio, Reynolds number, bubble size, and bubble injection location on the Cavitation Inception indices. The results indicate that, for all bubble sizes considered, the Cavitation Inception index increases as the jet slenderness ratio decreases. Larger bubbles entrain more rapidly into the cores of concentrated vortices than smaller bubbles, and the corresponding Inception indices are generally higher than those of smaller bubbles. The Inception indices for larger bubbles are insensitive to the injection location, while the Inception indices of smaller bubbles tend to increase when they are injected inside the shear layer near the nozzle lip. Although it affects the bubble distributions, variation of the Reynolds number leads to insignificant changes in pressure minima and in the Inception indices of larger bubbles, having noticeable effect only on the Inception indices of smaller bubbles. Computed results are consistent with, and provide plausible explanations for, several trends observed in recent jet Cavitation experiments.
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Pressure fluctuations and their effect on Cavitation Inception within water jets
Journal of Fluid Mechanics, 1994Co-Authors: Bing Ran, Joseph KatzAbstract:Instantaneous and phase averaged pressure distributions in the near field of a jet, and their effects on the conditions for the onset of Cavitation are studied in detail. The measurements are performed by using microscopic bubbles as pressure sensors, and holography as a means of detecting them. Experiments are performed at Re d exceeding 4 × 10 5 , with and without acoustic excitation. The results show that the highest negative pressure peaks (–0.97) and the resulting Cavitation Inception occur because of vortex pairing. Prior to pairing the negative peaks are between –0.8 and –0.9. Weak acoustic excitation changes the entire flow structure and the spatial distributions of bubbles, but has little effect on the onset of Cavitation. Downstream of the potential core the highest pressure peaks (∼ –0.6) are considerably smaller, in agreement with the occurrence of Cavitation there. It is also shown that although the r.m.s. values of pressure fluctuations do not vary with the jet speed, the probability distribution changes significantly, causing a reduction in the Inception index with increasing velocity. The probability of Cavitation Inception is estimated from the distributions of bubbles and pressure peaks. It is shown that the actual, non-uniform bubble distribution increases the probability of Inception owning to migration of the bubbles to the low pressure regions.
Chao-tsung Hsiao - One of the best experts on this subject based on the ideXlab platform.
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Numerical Study of Cavitation Inception Due to Vortex/Vortex Interaction in a Ducted Propulsor
Journal of Ship Research, 2008Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:Cavitation Inception in a ducted propulsor was studied numerically using Navier-Stokes computations and bubble dynamics models. Experimental observations of the propulsor model and previous numerical computations using Reynolds-averaged Navier-Stokes (RANS) codes indicated that Cavitation Inception occurred in the region of interaction of the leakage and trailing tip vortices. The RANS simulations failed, however, to predict correctly both the Cavitation Inception index value and the Inception location. To improve the numerical predictions, we complemented here the RANS computations with a direct Navier-Stokes simulation in a reduced computational domain including the region of interaction of the two vortices. Initial and boundary conditions in the reduced domain were provided by the RANS solution of the full ducted propulsor flow. Bubble nuclei were released in this flow field, and spherical and nonspherical bubble dynamics models were exercised to investigate Cavitation Inception. This resulted in a solution in much better agreement with the experimental measurements than the original RANS solution. Both the value of the Cavitation Inception index and the location of the Cavitation Inception were very well captured. The characteristics of the emitted acoustic signals and of the bubble shapes during a Cavitation event were also computed.
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numerical study of Cavitation Inception due to vortex vortex interaction in a ducted propulsor
Journal of Ship Research, 2008Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:Cavitation Inception in a ducted propulsor was studied numerically using Navier-Stokes computations and bubble dynamics models. Experimental observations of the propulsor model and previous numerical computations using Reynolds-averaged Navier-Stokes (RANS) codes indicated that Cavitation Inception occurred in the region of interaction of the leakage and trailing tip vortices. The RANS simulations failed, however, to predict correctly both the Cavitation Inception index value and the Inception location. To improve the numerical predictions, we complemented here the RANS computations with a direct Navier-Stokes simulation in a reduced computational domain including the region of interaction of the two vortices. Initial and boundary conditions in the reduced domain were provided by the RANS solution of the full ducted propulsor flow. Bubble nuclei were released in this flow field, and spherical and nonspherical bubble dynamics models were exercised to investigate Cavitation Inception. This resulted in a solution in much better agreement with the experimental measurements than the original RANS solution. Both the value of the Cavitation Inception index and the location of the Cavitation Inception were very well captured. The characteristics of the emitted acoustic signals and of the bubble shapes during a Cavitation event were also computed.
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Scaling of Tip Vortex Cavitation Inception Noise With a Bubble Dynamics Model Accounting for Nuclei Size Distribution
Journal of Fluids Engineering, 2005Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:The acoustic pressure generated by Cavitation Inception in a tip vortex flow was simulated in water containing a realistic bubble nuclei size distribution using a surface-averaged pressure (SAP) spherical bubble dynamics model. The flow field was obtained by the Reynolds-averaged Navier-Stokes computations for three geometrically similar scales of a finite-span elliptic hydrofoil. An acoustic criterion, which defines Cavitation Inception as the flow condition at which the number of acoustical peaks above a pre-selected pressure level exceeds a reference number per unit time, was applied to the three scales. It was found that the scaling of Cavitation Inception depended on the reference values (pressure amplitude and number of peaks) selected. Scaling effects (i.e., deviation from the classical σ i R 0.4 e ) increase as the reference Inception criteria become more stringent (lower threshold pressures and less number of peaks). Larger scales tend to detect more Cavitation Inception events per unit time than obtained by classical scaling because a relatively larger number of nuclei are excited by the tip vortex at the larger scale due to simultaneous increase of the nuclei capture area and of the size of the vortex core. The average nuclei size in the nuclei distribution was also found to have an important impact on Cavitation Inception number. Scaling effects (i.e., deviation from classical expressions) become more important as the average nuclei size decreases.
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Prediction of tip vortex Cavitation Inception using coupled spherical and nonspherical bubble models and Navier–Stokes computations
Journal of Marine Science and Technology, 2004Co-Authors: Chao-tsung Hsiao, Georges ChahineAbstract:A spherical and a nonspherical bubble dynamics models were developed to study Cavitation Inception, scaling, and dynamics in a vortex flow. The spherical model is a modified Rayleigh–Plesset model to account for bubble slip velocity and for nonuniform pressures around the bubble. The nonspherical model is embedded in an unsteady Reynolds-averaged Navier–Stokes code with appropriate free-surface boundary conditions and a moving chimera grid scheme around the bubble. The effect of nonspherical deformation and bubble/flow interaction on bubble dynamics is illustrated by comparing spherical and nonspherical models. It is shown that nonspherical deformations and bubble/flow interactions are important for an accurate prediction of Cavitation Inception. The surface-averaged pressure-modified Rayleigh–Plesset scheme is a significant improvement over the conventional spherical model, and is able to capture the volume changes of a bubble during its capture. It is also a fast scheme for studying scaling. In a preliminary study, the scaling effects on Cavitation Inception were examined using two different Reynolds numbers owing to two different chord lengths. The nuclei-size effect on the prediction of Cavitation Inception was also studied, and its important effects are highlighted.
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Prediction of tip vortex Cavitation Inception using coupled spherical and nonspherical bubble models and Navier-Stokes computations
Journal of Marine Science and Technology, 2004Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:A spherical and a nonspherical bubble dynamics models were developed to study Cavitation Inception, scaling, and dynamics in a vortex flow. The spherical model is a modified Rayleigh–Plesset model to account for bubble slip velocity and for nonuniform pressures around the bubble. The nonspherical model is embedded in an unsteady Reynolds-averaged Navier–Stokes code with appropriate free-surface boundary conditions and a moving chimera grid scheme around the bubble. The effect of nonspherical deformation and bubble/flow interaction on bubble dynamics is illustrated by comparing spherical and nonspherical models. It is shown that nonspherical deformations and bubble/flow interactions are important for an accurate prediction of Cavitation Inception. The surface-averaged pressure-modified Rayleigh–Plesset scheme is a significant improvement over the conventional spherical model, and is able to capture the volume changes of a bubble during its capture. It is also a fast scheme for studying scaling. In a preliminary study, the scaling effects on Cavitation Inception were examined using two different Reynolds numbers owing to two different chord lengths. The nuclei-size effect on the prediction of Cavitation Inception was also studied, and its important effects are highlighted.
Georges L. Chahine - One of the best experts on this subject based on the ideXlab platform.
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Numerical Study of Cavitation Inception Due to Vortex/Vortex Interaction in a Ducted Propulsor
Journal of Ship Research, 2008Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:Cavitation Inception in a ducted propulsor was studied numerically using Navier-Stokes computations and bubble dynamics models. Experimental observations of the propulsor model and previous numerical computations using Reynolds-averaged Navier-Stokes (RANS) codes indicated that Cavitation Inception occurred in the region of interaction of the leakage and trailing tip vortices. The RANS simulations failed, however, to predict correctly both the Cavitation Inception index value and the Inception location. To improve the numerical predictions, we complemented here the RANS computations with a direct Navier-Stokes simulation in a reduced computational domain including the region of interaction of the two vortices. Initial and boundary conditions in the reduced domain were provided by the RANS solution of the full ducted propulsor flow. Bubble nuclei were released in this flow field, and spherical and nonspherical bubble dynamics models were exercised to investigate Cavitation Inception. This resulted in a solution in much better agreement with the experimental measurements than the original RANS solution. Both the value of the Cavitation Inception index and the location of the Cavitation Inception were very well captured. The characteristics of the emitted acoustic signals and of the bubble shapes during a Cavitation event were also computed.
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numerical study of Cavitation Inception due to vortex vortex interaction in a ducted propulsor
Journal of Ship Research, 2008Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:Cavitation Inception in a ducted propulsor was studied numerically using Navier-Stokes computations and bubble dynamics models. Experimental observations of the propulsor model and previous numerical computations using Reynolds-averaged Navier-Stokes (RANS) codes indicated that Cavitation Inception occurred in the region of interaction of the leakage and trailing tip vortices. The RANS simulations failed, however, to predict correctly both the Cavitation Inception index value and the Inception location. To improve the numerical predictions, we complemented here the RANS computations with a direct Navier-Stokes simulation in a reduced computational domain including the region of interaction of the two vortices. Initial and boundary conditions in the reduced domain were provided by the RANS solution of the full ducted propulsor flow. Bubble nuclei were released in this flow field, and spherical and nonspherical bubble dynamics models were exercised to investigate Cavitation Inception. This resulted in a solution in much better agreement with the experimental measurements than the original RANS solution. Both the value of the Cavitation Inception index and the location of the Cavitation Inception were very well captured. The characteristics of the emitted acoustic signals and of the bubble shapes during a Cavitation event were also computed.
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Scaling of Tip Vortex Cavitation Inception Noise With a Bubble Dynamics Model Accounting for Nuclei Size Distribution
Journal of Fluids Engineering, 2005Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:The acoustic pressure generated by Cavitation Inception in a tip vortex flow was simulated in water containing a realistic bubble nuclei size distribution using a surface-averaged pressure (SAP) spherical bubble dynamics model. The flow field was obtained by the Reynolds-averaged Navier-Stokes computations for three geometrically similar scales of a finite-span elliptic hydrofoil. An acoustic criterion, which defines Cavitation Inception as the flow condition at which the number of acoustical peaks above a pre-selected pressure level exceeds a reference number per unit time, was applied to the three scales. It was found that the scaling of Cavitation Inception depended on the reference values (pressure amplitude and number of peaks) selected. Scaling effects (i.e., deviation from the classical σ i R 0.4 e ) increase as the reference Inception criteria become more stringent (lower threshold pressures and less number of peaks). Larger scales tend to detect more Cavitation Inception events per unit time than obtained by classical scaling because a relatively larger number of nuclei are excited by the tip vortex at the larger scale due to simultaneous increase of the nuclei capture area and of the size of the vortex core. The average nuclei size in the nuclei distribution was also found to have an important impact on Cavitation Inception number. Scaling effects (i.e., deviation from classical expressions) become more important as the average nuclei size decreases.
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Prediction of tip vortex Cavitation Inception using coupled spherical and nonspherical bubble models and Navier-Stokes computations
Journal of Marine Science and Technology, 2004Co-Authors: Chao-tsung Hsiao, Georges L. ChahineAbstract:A spherical and a nonspherical bubble dynamics models were developed to study Cavitation Inception, scaling, and dynamics in a vortex flow. The spherical model is a modified Rayleigh–Plesset model to account for bubble slip velocity and for nonuniform pressures around the bubble. The nonspherical model is embedded in an unsteady Reynolds-averaged Navier–Stokes code with appropriate free-surface boundary conditions and a moving chimera grid scheme around the bubble. The effect of nonspherical deformation and bubble/flow interaction on bubble dynamics is illustrated by comparing spherical and nonspherical models. It is shown that nonspherical deformations and bubble/flow interactions are important for an accurate prediction of Cavitation Inception. The surface-averaged pressure-modified Rayleigh–Plesset scheme is a significant improvement over the conventional spherical model, and is able to capture the volume changes of a bubble during its capture. It is also a fast scheme for studying scaling. In a preliminary study, the scaling effects on Cavitation Inception were examined using two different Reynolds numbers owing to two different chord lengths. The nuclei-size effect on the prediction of Cavitation Inception was also studied, and its important effects are highlighted.
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Scaling Effect on Prediction of Cavitation Inception in a Line Vortex Flow
Journal of Fluids Engineering, 2003Co-Authors: Chao-tsung Hsiao, Georges L. Chahine, Han-lieh LiuAbstract:The current study considers the prediction of tip vortex Cavitation Inception at a fundamental physics based level. Starting form the observation that Cavitation Inception detection is based on the monitoring of the interaction between bubble nuclei and the flow field, the bubble dynamics is investigated in detail. A spherical model coupled with a bubble motion equation is used to study numerically the dynamics of a nucleus in an imposed flow field. The code provides bubble size and position versus time as well as the resulting pressure at any selected monitoring position. This model is used to conduct a parametric study. Bubble size and emitted sound versus time are presented for various nuclei sizes and flow field scales in the case of an ideal Rankine vortex to which a longitudinal viscous core size diffusion model is imposed. Based on the results, one can deduce Cavitation Inception with the help of either an optical Inception criterion (maximum bubble size larger than a given value) or an acoustical Inception criterion (maximum detected noise higher than a given background value)
Eduard Amromin - One of the best experts on this subject based on the ideXlab platform.
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Prediction of Cavitation Inception in slots
International Journal of Multiphase Flow, 2019Co-Authors: Eduard AmrominAbstract:Abstract Cavitation Inception in slots on the flat walls is analyzed in the steady flow approach using a viscous-inviscid interaction method. It was assumed that, in the accordance with known observations, cavities appear as spherical bubbles in the cores of vortices near the slot corners. Computed Cavitation Inception numbers are compared with published experimental results of other authors within wide ranges of inflow parameters. The comparison shows a satisfactory agreement of computations with the measured data.
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Computation of Cavitation Inception numbers for 3D surface irregularities
Applied Ocean Research, 2018Co-Authors: Eduard AmrominAbstract:Abstract Cavitation Inception behind 3D surface irregularities often predetermines the vehicle acoustical performances. There are three flow scales influencing the Inception phenomenon: the body size; the irregularity heights; the radius of the core of vortices drifting in separation zone behind the irregularity. Cavities appear in these vortices. Existence of three scales challenges computations. The suggested multi-step iterative numerical method is a modification of the method already used by the author for Cavitation Inception behind 2D irregularities. The initial unsteady problem is broken down into two steady problems. The first of them is determination of the average separated flow behind the irregularity. This problem is solved using viscous-inviscid interaction approach, with 3D pressure computation. The second of them is determination of cavity equilibrium within the vortex core. This problem is solved with the assumption on a small influence of the vortex on the surrounding flow, but the vortex characteristics are linked to the computed turbulence characteristics in the separation zone. Intermediate validations with various experimental data are shown for all steps of the computational methods. Comparisons of computed and earlier measured Cavitation Inception numbers for hemispheres and cylinders submerged in the flat wall boundary layer are provided.
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Prediction of Cavitation Inception Within Regions of Flow Separation
Journal of Fluids Engineering, 2017Co-Authors: Eduard AmrominAbstract:Cavitation within regions of flow separation appears in drifting vortices. A two-part computational method is employed for prediction of Cavitation Inception number there. The first part is an analysis of the average flow in separation regions without consideration of an impact of vortices. The second part is an analysis of equilibrium of the bubble within the core of a vortex located in the turbulent flow of known average characteristics. Computed Cavitation Inception numbers for axisymmetric flows are in the good agreement with the known experimental data.
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Impact of Hydrofoil Material on Cavitation Inception and Desinence
Journal of Fluids Engineering-transactions of The Asme, 2017Co-Authors: Eduard AmrominAbstract:Flow-induced vibration of hydrofoils affects pressure pulsations on their surfaces and influences Cavitation Inception and desinence. As these pulsations depend on the hydrofoil material, Cavitation Inception and desinence numbers for hydrofoils of the same shape made from different metals can be substantially different. This conclusion is based on the comparison of the multistep numerical analysis of fluid–structure interaction for hydrofoils Cav2003 with earlier obtained experimental data for them. The material impact on Cavitation must be taken into account in future experiments.
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Approximate analysis of hydrofoil material impact on Cavitation Inception -1 Approximate analysis of hydrofoil material impact on Cavitation Inception
2016Co-Authors: Eduard AmrominAbstract:Flow-induced vibration of hydrofoils affects pressure pulsations on their surfaces and influences Cavitation Inception and desinence. Because these pulsations depend on the hydrofoil material, Cavitation Inception and desinence numbers for hydrofoils of the same shape made from the diverse metals are different. This conclusion is based on the comparison of the numerical solutions of the fluid-structure interaction problems with the data of the earlier performed experiments.
Xiaoxing Peng - One of the best experts on this subject based on the ideXlab platform.
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Study of tip vortex Cavitation Inception and vortex singing
Journal of Hydrodynamics, 2019Co-Authors: Xiaoxing Peng, Ling-xin Zhang, Benlong Wang, Mingtai Song, Yan-tao Cao, Liu Yuwen, Fang-wen Hong, Kai YanAbstract:Tip vortex Cavitation (TVC) is an important Cavitation phenomenon in marine propeller. The formation and evolution of tip vortex Cavitation are hot topics consistently both in engineering application and mechanism research. In this paper some recent studies on tip vortex Cavitation Inception and the noise of tip vortex Cavitation evolution are presented. The effects of both flow field and water qualities on tip vortex Cavitation Inception are considered by experiments and numerical simulations. The results show that besides the average minimum pressure in the vortex core the turbulence fluctuation and water qualities including air content and nuclei distribution have great influence on tip vortex Cavitation Inception. Based on the idea of first nucleus cavitating in tip vortex core new prediction formula for tip vortex Cavitation Inception is proposed. The synchronous technique of high speed video observation and noise measurement are adopted to study the development of tip vortex Cavitation. S-type total noise characteristics are obtained when Cavitation number from low to high. Vortex singing is found in the case where the tip vortex Cavitation just before leaves the tip region. The excited mechanism of vortex singing is proposed by analyzing the wave propagation on the interface of vortex cavity.
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The effect of water quality on tip vortex Cavitation Inception
Journal of Hydrodynamics, 2017Co-Authors: Ling-xin Zhang, Xiaoxing Peng, Linya Chen, Xueming ShaoAbstract:The Inception of tip vortex Cavitation is very sensitive to water quality. In order to quantify the effect of water quality on the Inception of tip vortex Cavitation, we develop a motion model to describe the migration and growth of nuclei in water. An analytical solution of migration of nuclei in a vortex flow is obtained so that the capture times of various nuclei can be given out directly. A criterion is built to determine the critical nucleus in a certain nuclei spectra distribution. Tensile strength of the critical nucleus is used to quantify the effect of water quality and correct the tip vortex Cavitation Inception number. Finally this change of Cavitation Inception number is compared with experimental results to validate our model.
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An acoustic approach to determine tip vortex Cavitation Inception for an elliptical hydrofoil considering nuclei-seeding
International Journal of Multiphase Flow, 2017Co-Authors: Mingtai Song, Xiaoxing Peng, Denghai TangAbstract:Abstract Tip vortex Cavitation is usually the first type of propeller Cavitation to appear with intense noise. The precise prediction of tip vortex Cavitation Inception is of great importance. In this paper, via an acoustic approach an experimental investigation on tip vortex Cavitation Inception for an elliptical hydrofoil has been done in a Cavitation mechanism tunnel. For non-nuclei-seeding conditions, the sound level “collapses” when the tip vortex Cavitation approaches desinence and there exists an inverse N-shape curve between the sound pressure level and Cavitation number, drastically different from the generally known S-shape curve. Three nuclei-seeding conditions are then investigated to study the nuclei effects on the tip vortex Cavitation Inception. We propose an acoustic criterion to determine tip vortex Cavitation Inception applicable to both non-nuclei-seeding and nuclei-seeding conditions. The results confirm that the nuclei content and distribution in water indeed play an important role in the Cavitation Inception process. Supplemental observations from the high-speed video camera validate the proposed acoustic method.