Partially-Averaged Navier–Stokes method with modified k–ε model for cavitating flow around a marine propeller in a non-uniform wake

Wang, Xincheng; Wu, Yulin; Peng, Xiaoxing; Xu, Hongyuan

doi:10.1016/j.ijheatmasstransfer.2012.06.065

Cited by 108 publications

(37 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Though two-equation models can predict the general trend on TLV structures, over-prediction of the eddy viscosity has great limitations in the vortex shedding at the blade exit. Therefore, many advanced turbulence models with the modified eddy viscosity has sprung out (Wu et al, 2005;Ji et al, 2012;Liu et al, 2014). simulated the formation of three-dimensional tip leakage vortex cavitation cloud and periodic collapse of TLV induced suction-side perpendicular cavitating vortices (SSPCV) using an improved SST k- turbulence model and the homogeneous cavitation model, which is consistent with the observation reported by Tan et al (2015).…”

Section: Introductionsupporting

confidence: 78%

Visualized observations of trajectory and dynamics of unsteady tip cloud cavitating vortices in axial flow pump

Shi

Zhang

Zhao

et al. 2017

JFST

View full text Add to dashboard Cite

A large-scale perpendicular cavitating vortices (PCVs), at the trailing edge of attached cavitation on the blade suction side near the tip region, has been found recently due to the great impact on performance breakdown in an axial waterjet pump. However, the trajectory and dynamics of this structure have been given scant attention. In this study, some visualized experiments were carried out to elucidate the PCVs for different conditions. The high-speed imaging coupled with numerical computations show that the vortical cloud cavitation is induced by the combination of tip leakage vortex (TLV) and radial re-entrant jets from the hub to blade tip. Moreover, the trajectory and intensity of PCVs depend on the operating conditions strongly, whether the other parameters, e.g. blade number and blade geometries, are modified. When taken the blade number into consideration, as a consequence of flow passage width and blade loading distributions, the dynamics and strength of PCVs vary considerably. Furthermore, an optimum clearance geometry is seen to eliminate corner vortex and clearance cavitation when the clearance edge is rounded on the pressure side. However, the more intensive tip leakage vortex cavitation is observed due to the increased amount of leakage flux. Additionally, in the original blade with sharp edges, the PCVs is relative weak and has a loose structure, resulting in the multiple interaction with the next blade. These phenomenon are responsible for the severe performance degradation and flow instabilities in the tip region of an axial-flow pump. Lei Shi, Zhang, Zhao, Weidong Shi and van Esch, Journal of Fluid Science and Technology, Vol.12, No.1 (2017) 7 low pressure in the vortex core (Arndt, 2002;Higashi et al., 2002;Murayama, 2006). Thus, cavitation inception is often coupled with vortex structures, such as tip leakage, trailing and hub vortices as well as turbulent vortex structures developing in regions of flow separation.In the aforementioned research, much attention has been paid to the tip leakage vortex cavitation around the fully-wetted hydrofoils (Boulon et al., 1999;Park et al., 2006;Dreyer et al., 2014). Although many progress has been made in regard to the vortex structures and self-induced cavitation, some important parameters are still missing in actual hydraulic machines, for instance, the body force in rotating frame which can alter the cavitation phenomenon. As a result, for the practical applications, the numerical and experimental investigations have been carried out in many rotating machines, both for single and multiphase flows. Farrell and Billet (1994) measured the important variables for the correlation which predict the vortex minimum pressure in a high Reynolds number axial-flow test rig. Moreover, an optimum tip clearance has been theoretically identified as experiments have shown. Afterwards, a combined study of tip clearance and tip vortex cavitation in an axial flow pump was carried out by Laborde et al. (1997). A conclusion is drawn that cavitation inception is...

show abstract

Section: Introductionsupporting

confidence: 78%

Visualized observations of trajectory and dynamics of unsteady tip cloud cavitating vortices in axial flow pump

Shi

Zhang

Zhao

et al. 2017

JFST

View full text Add to dashboard Cite

show abstract

“…Besides, limited by the accuracy of test bed, small changes of performance may not be easily observed. CFD as a promising technique provides a powerful substitution and has been used in the research of rotating machinery [14,15] and PAT [16,17]. In this paper, effects of blade thickness influencing different specific speeds of PATs' performances were investigated using a validated CFD approach.…”

Section: Introductionmentioning

confidence: 99%

Research on Blade Thickness Influencing Pump as Turbine

Yang

Wang

Chen

et al. 2014

Advances in Mechanical Engineering

View full text Add to dashboard Cite

Research on the efficiency improvement of pump as turbine (PAT) is inadequate. Blade thickness is an important geometry parameter in blade design. To explore effects of blade thickness on the influence of PAT, numerical research on three different specific speeds of PATs with different blade thickness was carried out. Their performance changes with blade thickness were presented. Besides, the variations of hydraulic loss distribution with increasing blade thickness were performed. Theoretical analysis gives a reasonable explanation for the performance change. Results show that PAT's flow versus efficiency curve ( -) is lowered; flow versus head ( -) curve and flow versus power ( -) curve are increased with increasing blade thickness. The increase of -is mainly attributed to the increase of theoretical head caused by increasing blockage of impeller inlet area. Hydraulic loss distribution analysis indicates that the total hydraulic loss within PAT is increased with increasing blade thickness. The increase of -curve is a combined effect of the increase in theoretical head and the total hydraulic loss. The decrease of efficiency with increasing blade thickness indicates that the blade thickness of PAT should be as thin as possible if its strength could be met.

show abstract

“…It is a mathematical method that unifies the B spline curve and can accurately represent the curve [6][7][8]. In this paper, the NURBS curve is used to get 2D blade of ducted propeller and the NURBS surface is used to generate 3D ducted propeller.…”

Section: Three-dimensional Ducted Propellermentioning

confidence: 99%

Research on Rapid Generation of Ducted Propeller Model and Its Open Water Performance

Liu¹,

Song²

2017

Topics in Intelligent Computing and Industry Design (ICID)

View full text Add to dashboard Cite

Using coordinate transformation method, two-dimensional blade section of ducted propeller is converted to threedimensional coordinate system. The ducted propeller is built by NURBS surface. The generation of the ducted propeller is based on AutoCAD and Excel secondary development by Visual Basic 6.0. There, the ducted propeller model can be parameterized by one click. Calculating the thrust and torque values of ducted propeller at different speed coefficients by RNGk − ε turbulence model equation.

show abstract

Partially-Averaged Navier–Stokes method with modified k–ε model for cavitating flow around a marine propeller in a non-uniform wake

Cited by 108 publications

References 23 publications

Visualized observations of trajectory and dynamics of unsteady tip cloud cavitating vortices in axial flow pump

Visualized observations of trajectory and dynamics of unsteady tip cloud cavitating vortices in axial flow pump

Research on Blade Thickness Influencing Pump as Turbine

Research on Rapid Generation of Ducted Propeller Model and Its Open Water Performance

Contact Info

Product

Resources

About