Modelling of Incompressible Three-Dimensional Flow in Rotating Turbomachinery Passages

2002 ◽  
Author(s):  
C. Cravero ◽  
A. Satta ◽  
M. Marini
Keyword(s):  
Compressible Flows ◽  
Incompressible Flows ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Pump Impeller ◽  
Preconditioning Technique ◽  
Cfd Method ◽  
Flow Pump

A CFD method, previously developed by the authors for compressible flows, has been modified through a preconditioning technique to account for purely incompressible flows. Such a code is used to compute three-dimensional flows in a mixed flow pump impeller at design and off-design conditions. The results of the inviscid flow approach are critically discussed by comparison to available experimental data.

scholarly journals Study of Internal Flows in a Mixed-Flow Pump Impeller at Various Tip Clearances Using 3D Viscous Flow Computations

1990 ◽  
Author(s):  
Akira Goto
Keyword(s):  
Reverse Flow ◽  
Three Dimensional ◽  
Interaction Mechanism ◽  
Secondary Flows ◽  
Wake Flow ◽  
Navier Stokes ◽  
Tip Leakage Flow ◽  
Mixed Flow ◽  
Pump Impeller ◽  
Flow Pump

The complex three-dimensional flow fields in a mixed-flow pump impeller are investigated by applying the incompressible version of the Dawes’ 3D Navier-Stokes code. The applicability of the code is confirmed by comparison of computations with a variety of experimentally measured jet-wake flow patterns and overall performances at four different tip clearances including the shrouded case. Based on the computations, the interaction mechanism of secondary flows and the formation of jet-wake flow are discussed. In the case of large tip clearances, the reverse flow caused by tip leakage flow is considered to be the reason for the thickening of the casing boundary layer followed by the deterioration of the whole flow field.

Behavior of Air Bubbles in an Axial-Flow Pump Impeller

1983 ◽  
Vol 105 (3) ◽  
pp. 277-283 ◽  
Author(s):  
M. Murakami ◽  
K. Minemura
Keyword(s):  
Bubble Diameter ◽  
Three Dimensional ◽  
Axial Flow ◽  
Air Bubbles ◽  
Bubble Motion ◽  
Three Dimensional Flow ◽  
Surrounding Water ◽  
Pump Impeller ◽  
Axial Flow Pump ◽  
Flow Pump

Motion of air bubbles in a high-specific-speed axial-flow pump impeller was analyzed on the basis of measured streak lines of air bubbles in the impeller. The results were compared with those obtained by a numerical solution of the bubble motion equations for three dimensional flow. Governing factors of the bubble motion are the drag force due to the surrounding water and the force due to the pressure gradient. Trajectories of the bubbles deviate somewhat from the streamlines of water, and the amount of the deviation is dependent on the bubble diameter and also on specific-speeds of the pumps and flow rate of water.

Performance of a Mixed Flow Pump with Varying Tip Clearance: Part 1

1996 ◽  
Vol 210 (4) ◽  
pp. 305-318 ◽  
Author(s):  
T K Saha ◽  
S Soundranayagam
Keyword(s):  
Angular Momentum ◽  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Reversal ◽  
Tip Clearance ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Specific Speed ◽  
Flow Pump

Measurements of the three-dimensional flow field entering and leaving a mixed flow pump of non-dimensional specific speed k = 1.89 [ Ns = 100 r/min (metric)] are discussed as a function of flowrate. Flow reversal at inlet at reduced flows is seen to result in abnormally high total pressures in the casing region, but causes no noticeable discontinuities on the head-flow characteristics. Inlet prerotation is associated with the transport of angular momentum by the reversal eddy and begins with the initiation of flow reversal.

Research on the Geometry Parameters of Diffuser Vane Influence on the Performance of Bulb Tubular Pumping System

2017 ◽  
Author(s):  
Yan Jin ◽  
Junxin Wu ◽  
Hongcheng Chen ◽  
Chao Liu
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Design Parameters ◽  
Hydraulic Loss ◽  
Three Dimensional Flow ◽  
Pump System ◽  
Pumping System ◽  
Axial Flow Pump ◽  
Cfd Method ◽  
Flow Pump

Diffuser vane of tubular pump is different with that of the axial flow pump, since the diffusion angle after the impeller is larger than as usual, which is an important part of bulb tubular pump system. By calculating the hydraulic loss of each part of bulb tubular pump system, it is found that the hydraulic loss of diffuser vane is in large proportion of the whole hydraulic loss. For this situation, focuses on the design parameters of diffuser vane such as diffuser vane length, unilateral edge diffusion angle, equivalent diffusion angle are necessary. In this paper, CFD method is used to simulate the turbulent flow in a bulb tubular pumping system with two different diffuser vanes. The three dimensional flow fields in the whole passage of pumping system with different diffuser vanes are obtained. The results show that all the main geometry parameters of the diffuser vane design affect the performances of tubular pumping system, it should be chosen the parameters reasonably based on the actual situation.

Three-Dimensional Theory of Incompressible and Inviscid Flow Through Mixed Flow Turbomachines

1965 ◽  
Vol 87 (4) ◽  
pp. 361-372
Author(s):  
M. J. Schilhansl
Keyword(s):  
Radial Flow ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Two Dimensional ◽  
Surfaces Of Revolution ◽  
Dimensional Theory ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Flow Through ◽  
Flow Study

In this paper the author presents a three-dimensional flow study for mixed (axial and radial) flow rotors. In order to make the analysis manageable the actual stream surfaces are assumed to coincide with surfaces of revolution. The intersections of the blade surfaces with these surfaces of revolution are mapped onto planes normal to the axis of the rotor. The investigation of the flow in the “picture” planes is based on available two-dimensional cascade theories. Position and shape of the surfaces depend upon the equilibrium of the flow in the direction perpendicular to the surfaces of revolution. The flow in each individual surface of revolution is found by remapping from the planes. Improved position and shape of the surfaces of revolution can be derived from the equilibrium condition. This procedure must be iterated until two consecutive iterations lead to the same result.

Numerical Simulation of Three Dimensional Flow in Large Mixed-Flow Pump System

2011 ◽  
Author(s):  
Fan Yang ◽  
Chao Liu ◽  
Fangping Tang
Keyword(s):  
Pressure Distribution ◽  
Model Test ◽  
Static Pressure ◽  
Three Dimensional ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Pump System ◽  
Static Pressure Distribution ◽  
Calculation Results ◽  
Flow Pump

The three-dimensional flow inside a mixed-flow pump system was simulated by using CFX software. The Shear Stress Transport turbulent equation which combined k-ε and k-ω turbulent model was applied. The flow field in volute and discharge passage of the pump system was obtained and the hydraulic performances of the pump system were predicted. The velocity and pressure distribution in pump system were analyzed. From the calculation results it is evident that the flow in the double helix volute passage is a spiral movement combining axial and rotary flow; the static pressure distribution in the volute is symmetric; the uniformity of axial velocity distribution and velocity-weighted average swirl angle at the outlet section are relatively low; and static pressure distribution on pump blade surface is regular with higher static pressure on pressure side and lower one on the suction side. The axial forces decrease gradually with the decrease of lifting head and the radial forces decrease first and then increase. A model test of the pump system was conducted to verify the calculation results. The pressure fluctuation at certain sections of the pump system was measured from the model test. A good agreement was found for lifting head between calculated and measured results. While the deviation of the efficiency between calculated and measured results does exist in non design points which need to be improved.

Research on a Full Three-Dimenional Inverse Method for the Mixed-Flow Pump Runner

2002 ◽  
Author(s):  
Honggang Fan ◽  
Naixiang Chen ◽  
Lin Yang ◽  
Zhaohui Xu ◽  
Lunfu Qu ◽  
...  
Keyword(s):  
Inverse Method ◽  
Three Dimensional ◽  
New Method ◽  
Periodic Flow ◽  
Mean Flow ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Blade Shape ◽  
Flow Pump

In this paper, a full three-dimensional inverse method for the design of mixed-flow pump runner is described. The three-dimensional flow in the runner is decomposed into a tangential mean flow and a tangential periodic flow. The blades are represented by superposition of vortices and sources on the blade mean surface, and the blade mean surface is determined by the inverse method. In this method, the distribution of the circumferentially mean swirl VRθ on the meridional geometry of the runner is prescribed and the corresponding blade shape is computed iteratively. The new method is applied to the design of a mixed-flow pump runner and the result is satisfactory.

Suppression of Secondary Flows in a Mixed-Flow Pump Impeller by Application of Three-Dimensional Inverse Design Method: Part 2—Experimental Validation

1996 ◽  
Vol 118 (3) ◽  
pp. 544-551 ◽  
Author(s):  
A. Goto ◽  
T. Takemura ◽  
M. Zangeneh
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Flow Fields ◽  
Secondary Flows ◽  
Inverse Design ◽  
Suction Surface ◽  
Mixed Flow ◽  
Pump Impeller ◽  
Inverse Design Method ◽  
Flow Pump

In Part 1 of this paper, a mixed-flow pump impeller was designed by a fully three-dimensional inverse design method, aimed at suppressing the secondary flows on the blade suction surface. In this part, the internal flow fields of the impeller are investigated experimentally, using flow visualization and phase-locked measurements of the impeller exit flow, in order to validate the effects of secondary flow suppression. The flow fields are compared with those of a conventional impeller, and it is confirmed that the secondary flows on the blade suction surface are well suppressed and the uniformity of the exit flow fields is improved substantially, in both circumferential and spanwise directions. The effects of tip clearance and the number of blades for the inverse designed impeller are also investigated experimentally and numerically.

Study of Internal Flows in a Mixed-Flow Pump Impeller at Various Tip Clearances Using Three-Dimensional Viscous Flow Computations

1992 ◽  
Vol 114 (2) ◽  
pp. 373-382 ◽  
Author(s):  
A. Goto
Keyword(s):  
Reverse Flow ◽  
Three Dimensional ◽  
Interaction Mechanism ◽  
Secondary Flows ◽  
Wake Flow ◽  
Navier Stokes ◽  
Tip Leakage Flow ◽  
Mixed Flow ◽  
Pump Impeller ◽  
Flow Pump

The complex three-dimensional flow fields in a mixed-flow pump impeller are investigated by applying the incompressible version of Dawes’ Three-Dimensional Navier–Stokes code. The applicability of the code is confirmed by comparison of computations with a variety of experimentally measured jet-wake flow patterns and overall performances at four different tip clearances, including the shrouded case. Based on the computations, the interaction mechanism of secondary flows and the formation of jet-wake flow are discussed. In the case of large tip clearances, the reverse flow caused by tip leakage flow is considered to be the reason for the thickening of the casing boundary layer followed by the deterioration of the whole flow field.

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