Three Dimensional Numerical Simulation of Flow Field Inside a Reversible Pumping Station With Symmetric Aerofoil Blade

2008 ◽  
Author(s):  
Li Cheng ◽  
Chao Liu ◽  
Jiren Zhou ◽  
Fangping Tang ◽  
Yan Jin
Keyword(s):  
Flow Field ◽  
Control Volume ◽  
Three Dimensional ◽  
Flow Coefficient ◽  
Viscous Effects ◽  
Total Uncertainty ◽  
Pumping Station ◽  
Pumping System ◽  
Test Loop ◽  
Useful Power

The pumping station with symmetric aerofoil can achieve reversible pumping function. It can keep high reversible efficiency and its flow coefficient is approaching to normal one. At same time, it has the simple structure and is easy to operate and maintain. The flow inside reversible pumping station is very complex and dominated by three dimensional viscous effects. With the rapid progress of computational fluid dynamics, CFD has become an important tool to help to make full understanding of flow. In order to recognize the characteristic of pumping station, the control volume method is used to simulation the flow filed. The RNG k-ε turbulent model and SIMPLEC algorithm are applied to do analysis. Flow field inside symmetric aerofoil blade and passage of pumping station are analyzed in detail. Some computational data, such as computational contour of sections, streamline of pumping system, flow vectors of blade and pressure contour of blade for two different rotate directional, are given in the paper. On the based of the simulation results, efficiency prediction of the pumping station is applied. By calculating the useful power and the hydraulic efficiency at the 11 different discharge points, capabilities of pumping station are predicted. A set of model pumping station with a 300mm blade are made for test. Using the laboratory test loop of which the total uncertainty of measured efficiency is ±0.39%, the hydraulic performance is evaluated and demonstrated. The numerical performances agree well with experiment data.

Numerical Investigation of a Centrifugal Compressor for Supercritical CO2 Cycles

2020 ◽  
Author(s):  
Renan Emre Karaefe ◽  
Pascal Post ◽  
Marwick Sembritzky ◽  
Andreas Schramm ◽  
Francesca di Mare ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Flow Field ◽  
Numerical Simulations ◽  
Centrifugal Compressor ◽  
Supercritical Co2 ◽  
Solution Method ◽  
Three Dimensional ◽  
Solution Procedure ◽  
Test Loop

Abstract In this work, the performance characteristics and the flow field of a centrifugal compressor operating with supercritical CO2 are investigated by means of three-dimensional CFD. The considered geometry is based on main dimensions of the centrifugal compressor installed in the supercritical CO2 compression test-loop operated by Sandia National Laboratories. All numerical simulations are performed with a recently developed in-house hybrid CPU/GPU compressible CFD solver. Thermodynamic properties are computed through an efficient and accurate tabulation technique, the Spline-Based Table Look-Up Method (SBTL), particularly optimised for the applied density-based solution procedure. Numerical results are compared with available experimental data and accuracy as well as potentials in computational speedup of the solution method in combination with the SBTL are evaluated in the context of supercritical CO2 turbomachinery.

Computation of the Flow Field of Transonic Axial Compressor by Steady Arbitrary Lagrangian Eulerian Formulation

2008 ◽  
Author(s):  
Adel Ghenaiet ◽  
Nouredine Djeghri
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Arbitrary Lagrangian Eulerian ◽  
Viscous Effects ◽  
Stability Range ◽  
Transonic Compressor ◽  
Ale Formulation ◽  
Transonic Axial Compressor ◽  
Residual Smoothing

This paper presents a multi-block solver dealing with an inviscid three dimensional compressible flow through a transonic compressor blading. For efficient computations of the 3D time dependant Euler equations, this solver that we have developed has been cast within a stationary ALE ‘Arbitrary Lagrangian Eulerian’. The main contribution of this paper is by consolidating this ALE formulation, to alleviate the shortcomings linked to rotation effects and the mixed relative subsonic–supersonic inlet flow conditions, which are now simply implemented through an absolute subsonic flow velocity. The finite volume based solver is using the central differencing scheme known as JST (Jameson-Schmidt-Turkel). The explicit multistage Runge-Kutta algorithm is used as a pseudo time marching to the steady-state, coupled with two convergence accelerating techniques; the variable local time-stepping and the implicit residual smoothing procedure. The adaptive implicit residual smoothing has extended the stability range of this explicit scheme, and proved to be successful in accelerating the rate of convergence. This code is currently being extended to include viscous effects, where fluxes are discretized based on Green’s theorem. To support this solver, an H type grid generator based on algebraic and elliptic methods has been developed. The segmentation of the complete domain into smaller blocks has provided full topological and geometrical flexibilities. The code was used to compute the flow field of a transonic axial compressor NASA rotor 37, and comparisons between the calculations and some available experimental data under the design speed and part speed, show qualitatively good agreement.

An Analysis Method for Multistage Transonic Turbines With Coolant Mass Flow Addition

1998 ◽  
Vol 120 (4) ◽  
pp. 744-752 ◽  
Author(s):  
F. Mildner ◽  
H. E. Gallus
Keyword(s):  
Flow Field ◽  
Mass Flow ◽  
Three Dimensional ◽  
Iterative Solution ◽  
Curvilinear Coordinates ◽  
Main Stream ◽  
Viscous Effects ◽  
Air Mixing ◽  
Volume Method ◽  
Cooling Air

The subject of this paper is a numerical method for the calculation of the transonic flow field of multistage turbines, taking high coolant flow into account. To reduce the processing time, a throughflow method based on the principels of Wu is used for the hub-to-tip calculation. The flow field is obtained by an iterative solution between a three-dimensional inviscid hyperbolic time-dependent algorithm with an implicit finite volume method for the blade-to-blade calculations using C-meshes and a single representative meridional S2m-streamsurface. Along the S2m-plane with respect to nonorthogonal curvilinear coordinates, the stream function equation governing fluid flow is established. The cooling air inflow inside the blade passage forbids the assumption of a constant mass flow along the main stream direction. To consider the change of the aerodynamic and thermodynamic behavior, a cooling air model was developed and implemented in the algorithm, which allows the mixing of radially arbitrarily distributed cooling air in the trailing edge section of each blade row. The viscous effects and the influence of cooling air mixing are considered by the use of selected loss correlations for profile, tip leakage, secondary flow and mixing losses in the S2m-plane in terms of entropy. The method is applied to the four-stage high-temperature gas turbine Siemens KWU V84.3. The numerical results obtained are in good agreement with the experimental data.

scholarly journals Loss and Deviation in Windmilling Fans

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Ewan J. Gunn ◽  
Cesare A. Hall
Keyword(s):  
Control Volume ◽  
Three Dimensional ◽  
Flow Coefficient ◽  
High Loss ◽  
Pressure Surface ◽  
Blade Row ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Transonic Fan ◽  
Cruise Flight

For an unpowered turbofan in flight, the airflow through the engine causes the fan to freewheel. This paper considers the flow field through a fan operating in this mode, with emphasis on the effects of blade row losses and deviation. A control volume analysis is used to show that windmilling fans operate at a fixed flow coefficient which depends on the blade metal and deviation angles, while the blade row losses are shown to determine the fan mass flow rate. Experimental and numerical results are used to understand how the loss and deviation differ from the design condition due to the flow physics encountered at windmill. Results are presented from an experimental study of a windmilling low-speed rig fan, including detailed area traverses downstream of the rotor and stator. Three-dimensional computational fluid dynamics (CFD) calculations of the fan rig and a representative transonic fan windmilling at a cruise flight condition have also been completed. The rig test results confirm that in the windmilling condition, the flow through the fan stator separates from the pressure surface over most of the span. This generates high loss, and the resulting blockage changes the rotor work profile leading to modified rotational speed. In the engine fan rotor, a vortex forms at the pressure surface near the tip and further loss results from a hub separation caused by blockage from the downstream core and splitter.

The Relative Merits of an Inviscid Euler 3-D and Quasi-3-D Analysis for the Design of Transonic Rotors

1988 ◽  
Author(s):  
D. P. Miller ◽  
A. C. Bryans
Keyword(s):  
Flow Field ◽  
Numerical Solutions ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Viscous Effects ◽  
Blade Loading ◽  
Rotor Design ◽  
Accurate Indication ◽  
Through Flow ◽  
Transonic Rotor

It is the purpose of this paper to examine the flow fields in an advanced modern transonic rotor design using both axisymmetric and three dimensional techniques. Also, to determine the deviation of the axisymmetric flow from three-dimensional flow field and whether this seriously affects the results. Inviscid Euler solvers are now widely used to analyze transonic flows through turbomachines giving a reasonably accurate indication of the flow field in blade passages. Although viscous effects are important, the inviscid analysis provides significant knowledge of the flow field which is essential to transonic design. The blade-to-blade loading and work distributions are determined quite realistically by the 3-D and quasi-3-D inviscid analyses. Through-flow and blade-to-blade inviscid solutions are presented for a highly loaded transonic rotor. Numerical solutions for various transonic rotor designs operating at peak efficiency are also compared with test data.

Research of Tubular Pumping Systems on Dual-Directional Operation

2009 ◽  
Author(s):  
Long Li ◽  
Wang Ze ◽  
Xuelin Yang ◽  
Dan Li
Keyword(s):  
Fluid Flow ◽  
Vortex Flow ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Experiment Data ◽  
Navier Stokes Equations ◽  
Diffuse Flow ◽  
Pumping Station ◽  
Pumping System

The tubular pumping system on dual-directional operation is used extensively for drainage and feedwater pumping stations of the cities and towns. The performance of the dual-directional operation of pumping systems is different with that of simple-way operation. The article described the three-dimensional fluid flow and the predicted performance of the numerical investigation inside a tubular pumping station on dual-directional operation, based on the Reynolds time-averaged Navier-Stokes equations and the realizable k-ε turbulent flow model, applied the law-of-wall and sliding mesh technique, and comparing with the experiment data. The main phenomena existing in pressure contours, velocity contours, velocity vectors and flow lines is showed. The disturbance of fluid flow from the pump outlet to pumping station channel is researched. The axial-whirling flow, circulation-vortex flow is discovered inside discharge diffuser of tubular pumping station on feed-directional operation. The axial-whirling flow is strengthened as a result of diffuse flow. The circulation-vortex flow of the impeller outlet is enhanced in the radius and reduced in the middle of discharge diffuser without guide vanes. There is more loss of head in discharge diffuser of the channel, comparing with that of the suction reducer. It was a close predicted performance of numerical simulation with that of the experiment in the best efficiency point. There was a more difference between the predicted performances with that of the experiment data on the feedwater-directional operation, comparing that of the drainagewater -directional operation.

scholarly journals An Analysis Method for Multistage Transonic Turbines With Coolant Mass Flow Addition

1997 ◽  
Author(s):  
Frank Mildner ◽  
Heinz E. Gallus
Keyword(s):  
Flow Field ◽  
Mass Flow ◽  
Three Dimensional ◽  
Iterative Solution ◽  
Curvilinear Coordinates ◽  
Main Stream ◽  
Viscous Effects ◽  
Air Mixing ◽  
Orthogonal Curvilinear Coordinates ◽  
Cooling Air

The subject of this paper is a numerical method for the calculation of the transonic flow field of multistage turbines taking high coolant flow into account. To reduce the processing time, a throughflow method based on the principels of Wu is used for the hub-to-tip calculation. The flow field is obtained by an iterative solution between a three dimensional inviscid hyperbolic time-dependent algorithm with an implicit finite volume method for the blade-to-blade calculations using C-meshes and a single representative meridional S2m-stream surface. Along the S2m-plane with respect to non-orthogonal curvilinear coordinates, the stream function equation governing fluid flow is established. The cooling air inflow inside the blade passage forbids the assumption of a constant mass flow along the main stream direction. To consider the change of the aerodynamic and thermodynamic behaviour, a cooling air model was developed and implemented in the algorithm, which allows the mixing of radially arbitrarily distributed cooling air in the trailing edge section of each blade row. The viscous effects and the influence of cooling air mixing are considered by the use of selected loss correlations for profile-, tip leakage, secondary flow and mixing losses in the S2m-plane in terms of entropy. The method is applied to the four stage high temperature gas turbine Siemens KWU V84.3. The obtained numerical results are in good agreement with the experimental data.

The Study on the Flow Fields and Hydraulic Performance in the Pump Sump

2007 ◽  
Author(s):  
Li Cheng ◽  
Chao Liu ◽  
Jiren Zhou ◽  
Fangping Tang ◽  
Hua Yang
Keyword(s):  
Control Volume ◽  
Three Dimensional ◽  
Flow Fields ◽  
Viscous Effects ◽  
Back Wall ◽  
Pump Station ◽  
Computational Data ◽  
Simplec Algorithm ◽  
Pump Sump ◽  
Volume Method

The pump sump, which connects forebay and intake of pump station, supplies good flow condition for the intake of the pump. The flow inside pump sump is very complex and dominated by three dimensional viscous effects. In order to recognize the characteristic of pump sump, the control volume method is used to simulation the flow filed. The RNG k-ε turbulent model and SIMPLEC algorithm are applied to do analysis. Flow fields inside pump sump are analyzed in details. A lot of computational data, such as computational contour of sections, streamline, flow vectors and pressure contour, are given in the paper. On the based of the simulation results, best plane shapes and suitable dimensions of sump are presented. Relationship between flow patterns and dimensions of sump, such as back wall clearance, bellmouth height and shape of back wall etc, was discussed. The recommenced parameters are brought out. The results show that numerical flow fields agree well with experiment data measured by 3D-PIV model test.

Theoretical Study of Electroosmotic Flow With Replacement Solutions

2005 ◽  
Author(s):  
Zhanjie Shao ◽  
Carolyn L. Ren ◽  
Gerry Schneider
Keyword(s):  
Flow Field ◽  
Electroosmotic Flow ◽  
Control Volume ◽  
Three Dimensional ◽  
Concentration Field ◽  
Simple Algorithm ◽  
Electrolyte Solutions ◽  
Flow Structures ◽  
Cross Sectional ◽  
Finite Control

Electroosmotic flow with solution displacement in microchannels is often encountered in many lab-on-a-chip devices where washing procedures are designed. In order to investigate the detailed flow structures for a displacement process between two different electrolyte solutions, a three-dimensional numerical model is developed in this paper. KCl solution and LaCl3 solution are mainly used as sample solutions. A 2cm long straight microchannl with a rectangle cross sectional area (height of 100μm and width of 200 μm) was employed in this study. The governing equations of applied electrical field, flow field and concentration field were numerical solved with SIMPLE algorithm, which are based on a finite control volume scheme. The observed flow structures such as back flow in the center of the channel and distortion of plug-like electroosmotic velocity profile are discussed in detail. It is found that the distortion in flow field is due to the induced pressure gradient, which is resulted from the nonuniformity of electroosmotic mobilities and electrical conductivities of two solutions. Finally, the displacement between DIUF water and LaCl3 solution is briefly studied.

scholarly journals Study on Three-Dimensional Inner Flow Field Characteristics and Performance of Scramjet

2019 ◽  
Vol 288 ◽  
pp. 02007
Author(s):  
Feng Gao ◽  
Jie Zhao ◽  
Cheng Tao Zhang
Keyword(s):  
Aspect Ratio ◽  
Flow Field ◽  
Total Pressure ◽  
Static Pressure ◽  
Three Dimensional ◽  
Flow Coefficient ◽  
Recovery Coefficient ◽  
Inlet Flow ◽  
And Performance ◽  
Pressure Recovery Coefficient

The three-dimensional characteristics and performance of the flow field in the inlet of the scramjet engine were numerically simulated by CFD software. The flow characteristics in the width direction of the inlet and the influence of the aspect ratio on the performance of the inlet were studied. The calculation results show that the inlet flow has obvious three-dimensional characteristics, and the flow field structure is different in the width direction from the middle symmetrical section to the side wall surface, the Mach number is smaller and smaller, the static pressure is lower and lower, and the static temperature is higher, the greater the total pressure. The aspect ratio has little effect on the Mach number and static temperature of the outlet section of the inlet, but it has a great influence on the static pressure and total pressure. Within a reasonable range, the aspect ratio is doubled, the static pressure is increased by about 40%, and the total pressure is increased by about 84%. The inlet flow coefficient and the total pressure recovery coefficient increase as the aspect ratio increases. Within a reasonable range, the aspect ratio is doubled, the inlet flow coefficient is increased by approximately 53%, and the total pressure recovery coefficient is increased by approximately 83%.

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