Investigation of Pressure Fluctuations Caused by Turbulent and Cavitating Flow Around a P1356 Ship Propeller

2008 ◽  
Author(s):  
C Lifante ◽  
◽  
T Frank ◽  
K Rieck ◽  
◽  
...  
Keyword(s):  
Pressure Fluctuations ◽  
Cavitating Flow ◽  
Ship Propeller

Numerical Simulation and Vorticity Analysis of Cavitating Flow Around a Marine Propeller Behind the Hull

2019 ◽  
Author(s):  
Yun Long ◽  
Chengzao Han ◽  
Bin Ji ◽  
Xinping Long ◽  
Zhirong Zhang
Keyword(s):  
Experimental Data ◽  
Pressure Fluctuations ◽  
Relative Vorticity ◽  
Cavitating Flow ◽  
Numerical Results ◽  
Tip Vortex ◽  
Marine Propeller ◽  
Thrust Coefficient ◽  
Sheet Cavitation ◽  
Vorticity Transport

Abstract In this paper, the unsteady cavitating turbulent flow around a marine propeller behind the hull is simulated by the k-ω SST turbulence model coupled with the Zwart cavitation model. Three systematic refined structured meshes around the hull and propeller have been generated to study the predicted cavitation patterns and pressure fluctuations. Numerical results indicate that the predicted transient cavitating flow behind the hull wake, including sheet cavitation and tip vortex cavitation, shows quasi-periodic feature and agrees fairly well with the available experimental data. The deviations of pressure fluctuations between experimental data and numerical results are much small. With mesh refining, the cavitation region and the magnitudes of the calculated pressure fluctuations increase, while the differences between two adjacent sets of grids become smaller. In addition, the uncertainty of the thrust coefficient obtained by Factor of Safety method is significantly small. Further, the interaction between the cavitation and the vortex by the relative vorticity transport equation is illustrated. Results show that the magnitude of stretching term is obviously larger than the other three terms, and the dilatation term and the baroclinic term both have an important influence on the generation of vortices.

Numerical Study of Unsteady Cavitating Flow in an Inducer with Omega Vortex Identification

2022 ◽  
Author(s):  
Yan Longlong ◽  
Bo Gao ◽  
Dan Ni ◽  
Ning Zhang ◽  
Wenjie Zhou
Keyword(s):  
Numerical Study ◽  
Pressure Fluctuations ◽  
Cavitating Flow ◽  
Vortical Flow ◽  
Flow Structures ◽  
Clear Correlation ◽  
Vortex Identification ◽  
Design Point ◽  
Identification Method ◽  
Unsteady Cavitating Flow

Abstract To accurately capture the behaviors of cavitation and reveal the unsteady cavitating flow mechanism, a condensate pump inducer is numerically analyzed in a separate numerical experiment with LES at critical cavitation number sind,c under the design point. Based on the new Omega vortex identification method, the correction between the flow structures and cavities is clearly illustrated. Besides, the pressure fluctuations around the inducer are analyzed. Special emphasis is put on the analysis of the interactions between the cavities, turbulent fluctuations, and vortical flow structures. The Omega vortex identification method could give an overall picture of the whole cavitating flow structures to present a clear correlation between the vortices and cavities. The results show that the shear cavitation dominant the cavitation characteristics under the design point. The pure rigid rotation region mainly concentrates at the edge of the cavities while the other sheet-like cavities near the casing walls are characterized by strong turbulence fluctuations. Besides, based on the analysis of the correlation between the cavities and flow structures, the rotating cavitation under the design point may mainly attribute to the interaction between the tip leakage vortex cavitation and the next blade.

Unsteady Numerical Simulation of Cavitating Turbulent Flow Around a Highly Skewed Model Marine Propeller

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
Bin Ji ◽  
Xianwu Luo ◽  
Xin Wang ◽  
Xiaoxing Peng ◽  
Yulin Wu ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
Cavitating Flow ◽  
Tip Vortex ◽  
Wake Flow ◽  
Marine Propeller ◽  
Sheet Cavitation ◽  
Whole Process ◽  
Unsteady Numerical Simulation ◽  
Thrust And Torque

The cavitating flows around a highly skewed model marine propeller in both uniform flow and wake flow have been simulated by applying a mass transfer cavitation model based on Rayleigh–Plesset equation and k-ω shear stress transport (SST) turbulence model. From comparison of numerical results with the experiment, it is seen that the thrust and torque coefficients of the propeller are predicted satisfactory. It is also clarified from unsteady simulation of cavitating flow around the propeller in wake flow that the whole process of cavitating-flow evolution can be reasonably reproduced including sheet cavitation and tip vortex cavitation observed in the experiments. Furthermore, to study the effect of pressure fluctuation on the surrounding, pressure fluctuations induced by the cavitation as well as the propeller rotation are predicted at three reference positions above the propeller for comparison with the experimental data: The amplitudes of the dominant components corresponding to the first, second, and third blade passing frequencies were satisfactorily predicted. It is noted that the maximum difference of pressure fluctuation between the calculation and experiment reached 20%, which might be acceptable by usual engineering applications.

Numerical simulation of viscous cavitating flow around a ship propeller

2011 ◽  
Vol 25 (3) ◽  
pp. 539-548 ◽  
Author(s):  
Zhi-feng Zhu ◽  
Shi-liang Fang ◽  
Xiao-yan Wang ◽  
Zhao-wen Meng ◽  
Ping-xiang Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Cavitating Flow ◽  
Ship Propeller

A Numerical and Experimental Investigation of Wall-Pressure Fluctuations Induced by Sheet Cavitation Instabilities on Lifting Surface

2005 ◽  
Author(s):  
Jacques-Andre´ Astolfi ◽  
Jean-Baptiste Leroux ◽  
Olivier Coutier-Delgosha ◽  
Franc¸ois Deniset
Keyword(s):  
Flow Instability ◽  
Pressure Fluctuations ◽  
Homogeneous Medium ◽  
Cavitating Flow ◽  
Wall Pressure ◽  
Two Phase ◽  
Fluid Structure ◽  
Sheet Cavitation ◽  
Wall Pressure Fluctuations ◽  
Unsteady Loading

The paper is based on some previous works of the authors aimed to study the phenomenology of cavitation instabilities. In the present work, a particular attention is paid to the analysis of spatio-temporal wall-pressure fluctuations in the context of fluid structure coupling investigations. The work is based on a numerical and experimental study, whose objective was to analyze the wall-pressure fluctuations beneath an unsteady partial cavitating flow developing on an hydrofoil. Experiments were carried in a water tunnel, on a partially cavitating hydrofoil based on extended multi-point wall pressure measurements together with flow visualizations. 2D Navier-Stokes simulations solves the RANS equations combined with a physical model of cavitation The two-phase flow mixture is considered as a homogeneous medium for which the ratio of liquid and vapor is controlled by a barotropic state law. The numerical resolution is based on the SIMPLE algorithm, modified to take into account the high compressibility of the liquid/vapor mixture. The results show that various dynamics are caught by the model in agreement with the experiments. Two main unstable dynamics were observed leading to a strong variation of surface loading. The paper provides quantitative data about the severe unsteady loading that is experienced by the structure, which should very useful in a fully problem of Fluid Structure Interaction. The possibility of a structural response of the foil to the unsteady loading and how it could promote the cavitating flow instability is also discussed.

PRESSURE FLUCTUATIONS OF LIQUID-LIQUID SLUG FLOW IN CROSS-JUNCTION SQUARE MICROCHANNELS

2018 ◽  
Author(s):  
Jin-yuan Qian ◽  
Min-rui Chen ◽  
Zan Wu ◽  
Zhen Cao ◽  
Bengt Sunden
Keyword(s):  
Slug Flow ◽  
Pressure Fluctuations ◽  
Liquid Slug
Sign in / Sign up

Export Citation Format

Share Document