Analyses of Pressure Fluctuation and Fluctuation Reduction of an Automobile Fuel Pump

2016 ◽  
Author(s):  
Lu Zhang ◽  
Peng Wu ◽  
DaZhuan Wu
Keyword(s):  
Pressure Fluctuation ◽  
Static Pressure ◽  
Stokes Equations ◽  
Pressure Fluctuations ◽  
Navier Stokes ◽  
Arc Length ◽  
Navier Stokes Equations ◽  
Fuel Pump ◽  
Random Modulation ◽  
Spacing Method

The automobile fuel pump studied in this paper is a mini regenerative pump consisting of a casing with an axial channel and an impeller with 33 radial blades. In this study, the pressure fluctuation characteristics of the regenerative pump were analyzed with the method of unsteady CFD analysis. To investigate the pressure fluctuation, the unsteady Reynolds-averaged Navier-Stokes equations (URANS) were solved with realizable k-ε turbulence model using the CFD code FLUENT. To study the effect of arc length of stripper on the pressure fluctuation, the pressure fluctuations at several locations of pumps with strippers of different arc length were analyzed in time and frequency domain. The static pressure contours at different times were presented to reveal the generating mechanism of pressure fluctuation of the regenerative pump. For the purpose of pressure fluctuation reduction, a random modulation of blade spacing method was applied to design a new impeller with uneven spaced blades. The pressure fluctuations of four different pump units of the combination of different blade distribution impellers with casings of different arc length of stripper were studied and discussed. The pressure fluctuation of the pump unit of combination of random blade distribution impeller and large arc length stripper is significantly reduced. In this paper, the generating mechanism of pressure fluctuation for regenerative pump is uncovered, and a good solution to the fundamental pressure fluctuation reduction of regenerative pump is put forward.

scholarly journals Disconnected stationary solutions for 3D Kolmogorov flow problem: preliminary results

2021 ◽  
Vol 2090 (1) ◽  
pp. 012046
Author(s):  
Nikolay M. Evstigneev
Keyword(s):  
Flow Problem ◽  
Stokes Equations ◽  
Continuation Method ◽  
Fourier Method ◽  
Stationary Solutions ◽  
Navier Stokes ◽  
System Of Nonlinear Equations ◽  
Arc Length ◽  
Navier Stokes Equations ◽  
Numerical Bifurcation

Abstract The extension of the classical A.N. Kolmogorov’s flow problem for the stationary 3D Navier-Stokes equations on a stretched torus for velocity vector function is considered. A spectral Fourier method with the Leray projection is used to solve the problem numerically. The resulting system of nonlinear equations is used to perform numerical bifurcation analysis. The problem is analyzed by constructing solution curves in the parameter-phase space using previously developed deflated pseudo arc-length continuation method. Disconnected solutions from the main solution branch are found. These results are preliminary and shall be generalized elsewhere.

Analyses of Centrifugal Compressor Performance Impacts on Volute and Scroll

2010 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Static Pressure ◽  
Stokes Equations ◽  
Single Stage ◽  
Navier Stokes ◽  
Performance Tests ◽  
Peak Efficiency ◽  
Navier Stokes Equations ◽  
Flow Simulations ◽  
Compressor Performance ◽  
Compressor Efficiency

Volute is used to collect and transport swirling gas produced by impeller or diffuser. Design of the volute not only impacts compressor efficiency but also influences the operating ranges of the compressor. In this study, Navier-Stokes equations combined with an algebra turbulence model were used to simulate flows inside a single stage compressor. Detailed flow simulations for a large cut back tongue volute are presented and discussed. A rounded tongue volute was tested in a single stage test rig. The compressor stage performance tests were conducted in the test lab and static pressure taps were used to measure static pressures at volute internal walls at locations of θ = 240° and 360°. Thermal couples and other static pressure probes were instrumented at inlet and outlet of the compressor for performance tests. The numerical results were compared with experiments and good agreements are found. Studies showed that a large cut back rounded tongue volute provided good operating range without dramatically dropping compressor peak efficiency.

The Interaction Between the Impeller and Casing in a Small-Size Turbo-Compressor

2002 ◽  
Author(s):  
D.-W. Kim ◽  
Youn J. Kim
Keyword(s):  
Static Pressure ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Reference Method ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Pressure Distributions ◽  
Loss Coefficients ◽  
Compressible Turbulent Flow ◽  
Turbo Compressor

The effects of casing shape on the performance and the interaction between the impeller and casing in a small-size turbo-compressor are investigated. Numerical analysis is conducted for the compressor with circular and single volute casings from inlet to discharge nozzle. In order to predict the flow pattern inside the entire impeller, vaneless diffuer and casing, calculations with multiple frames of reference method between the rotating and stationery parts of the domain are carried out. For compressible turbulent flow fields, the continuity and three-dimensional time-averaged Navier-Stokes equations are employed. To evaluate the performance of two types of casings, the static pressure and loss coefficients are obtained with various flow rates. Also, static pressure distributions around casings are studied for different casing shapes, which are very important to predict the distribution of radial load. To prove the accuracy of numerical results, measurements of static pressure around casing and pressure difference between the inlet and outlet of the compressor are performed for the circular casing. Comparison of these results between the experimental and numerical analyses are conducted, and reasonable agreement is obtained.

Unsteady Vortices and Blade Loading in a High-Pressure Turbine

2009 ◽  
Author(s):  
Dongil Chang ◽  
Stavros Tavoularis
Keyword(s):  
High Pressure ◽  
Stokes Equations ◽  
Pressure Fluctuations ◽  
Rotor Blades ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Time Resolved ◽  
Blade Loading ◽  
Pressure Losses ◽  
Horseshoe Vortices

Unsteady flow in a transonic, single-stage, high-pressure, axial turbine has been investigated numerically by solving the URANS (Unsteady Reynolds-Averaged Navier-Stokes) equations with the SST (Shear Stress Transport) turbulence model. Interest has focused on the identification and effects of the quasi-stationary vane and blade horseshoe vortices, vane and blade passage vortices, vane and blade trailing edge vortices, and blade tip leakage vortices. Moreover, two types of unsteady vortices, not discussed explicitly in the previous literature, have been identified and termed “axial gap vortices” and “crown vortices”. All vortices have been clearly and distinctly identified using a modified form of the Q criterion, which is less sensitive to the set threshold than the original version. The use of pathlines and iso-contours of static pressure, axial vorticity and entropy has been further exploited to distinguish the different types of vortices from each other and to mark their senses of rotation and strengths. The influence of these vortices on the entropy distribution at the outlet has been investigated. The observed high total pressure losses in the turbine at blade midspan have been connected to the action of passage vortices. The formation and disappearance processes of unsteady vortices located in the spacing between the stator and the rotor have been time-resolved. These vortices are roughly aligned with the leading edges of the rotor blades and their existence depends on the position of the blade with respect to the upstream vanes. In addition, the present study focuses on the unsteady blade loading that influences vibratory stresses. Contours of the time-dependent surface pressure on the rotor blade have demonstrated the presence of large pressure fluctuations near the front of the blade suction sides; these pressure fluctuations have been associated with the periodic passages of shock waves originating at the vane trailing edges.

Pressure Fluctuation Reduction in Side Channel Pumps Using a Modified Impeller Blade

2019 ◽  
Author(s):  
Xueyuan Wei ◽  
Fan Zhang ◽  
Desmond Appiah ◽  
Ke Chen ◽  
Shouqi Yuan ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Stokes Equations ◽  
Outer Radius ◽  
Navier Stokes ◽  
Side Channel ◽  
Impeller Blade ◽  
Navier Stokes Equations ◽  
Fluctuation Intensity ◽  
Noise Vibration ◽  
Vibration Performance

Abstract For the unique performance advantages of side channel pump delivering flows at high heads, it has been applied in many fields such as petrochemical, pharmaceutical, food processing, automobile fuel pumping etc. However, the operation of the pump is strongly affected by the intensity of the pressure fluctuation, thus the pressure fluctuation exiting within the pump cannot be neglected because of its direct influence on the noise and vibration performance. Therefore, reducing the pressure fluctuation intensity is a key point for research. The side channel pump studied in this paper is a prototype with an axial channel and a 24-blade impeller. The pressure fluctuation intensity of the pump is studied using numerical simulations at best efficiency point. The Reynolds-averaged Navier-Stokes equations (URANS) are solved with the Shear Stress Transport (SST) k-ω turbulence model using commercial CFX codes. The time and frequency plots of the pressure fluctuation coefficient, Cp of the original impeller scheme at different monitoring points revealed high pressure fluctuation intensities affecting the pump’s operating reliability. For the purpose of reducing the pressure fluctuation intensity in the pump, the impeller geometry is modified with a small blade at the outer radius. The study showed that the pressure fluctuation within the pump is reduced significantly at the monitoring points. Moreover, it is found out that the pressure fluctuation in both impeller schemes are mainly caused by the flow exchange between the impeller and side channel. The results of this paper can provide reference for pressure fluctuation reduction and Noise-Vibration-Harshness (NVH) study in turbomachinery.

Investigation of the Flow in Centrifugal Compressor Volute

2008 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Static Pressure ◽  
Stokes Equations ◽  
Single Stage ◽  
Navier Stokes ◽  
Performance Tests ◽  
Test Rig ◽  
Peak Efficiency ◽  
Navier Stokes Equations ◽  
Flow Simulations ◽  
Compressor Efficiency

Volute is used to collect and transport swirling gas produced by impeller or diffuser. Design of the volute not only impacts compressor efficiency but also influences the operating ranges of the compressor. In this study, Navier-Stokes equations combined with an algebra turbulence model were used to simulate flows inside a single stage compressor. Detailed flow simulations for a large cut back tongue volute are presented and discussed. A rounded tongue volute was tested in a single stage test rig. The compressor stage performance tests were conducted in the test lab and static pressure taps were used to measure static pressures at volute internal walls at locations of θ = 240° and 360°. Thermal couples and other static pressure probes were instrumented at inlet and outlet of the compressor for performance tests. The numerical results were compared with experiments and good agreements are found. Studies showed that a large cut back rounded tongue volute provided good operating range without dramatically dropping compressor peak efficiency.

Development of a PISO-SPH method for computing incompressible flows

2013 ◽  
Vol 228 (3) ◽  
pp. 481-490 ◽  
Author(s):  
Ali Tayebi ◽  
Behzad Ghadiri Dehkordi
Keyword(s):  
Incompressible Flows ◽  
Stokes Equations ◽  
Pressure Fluctuations ◽  
Navier Stokes ◽  
Benchmark Problems ◽  
Sph Method ◽  
Navier Stokes Equation ◽  
Navier Stokes Equations ◽  
Particle Hydrodynamics ◽  
Incompressible Fluid Flows

A new algorithm is proposed for solving the time-dependent Navier-Stokes equations in a sequential uncoupled manner. The algorithm, known as PISO (Pressure Implicit with Splitting of Operators) is extended to the Smoothed Particle Hydrodynamics (SPH) context (PISO-SPH). The algorithm consists of one prediction and two correction steps, based on a full Navier-Stokes equation, therefore, a modified Poisson equation is derived which makes the algorithm more stable with less pressure fluctuations. The proposed PISO-SPH method is applied to solve a number of benchmark problems including both unsteady and steady state test cases. Comparing the results with analytical solutions and other numerical methods, it is shown that the proposed method is accurate and straightforward for the simulation of incompressible fluid flows.

Prediction of Cascade Flow Fields Using the Averaged Navier-Stokes Equations

1984 ◽  
Vol 106 (2) ◽  
pp. 383-390 ◽  
Author(s):  
S. J. Shamroth ◽  
H. McDonald ◽  
W. R. Briley
Keyword(s):  
Transonic Flow ◽  
Static Pressure ◽  
Stokes Equations ◽  
Solution Procedure ◽  
Navier Stokes ◽  
Compressor Cascade ◽  
Navier Stokes Equations ◽  
Cascade Flow ◽  
Model Predictions ◽  
Flow Through

A numerical solution procedure for the ensemble-averaged, compressible, time-dependent Navier-Stokes equations is applied to predict the flow about a cascade of airfoils operating in the transonic flow regime. The equations are solved by the consistently split, linearized block implicit (LBI) method of Briley and McDonald. Boundary conditions are set so as to specify upstream total pressure and downstream static pressure. Turbulence is modeled by a mixing length model. Predictions are made for flow through a compressor cascade configuration. The method yields converged solutions within a relatively small number of time steps ( ≈ 150), which give good comparisons with experimental data.

Numerical Simulation of Mixed Compression Intake Buzz

2017 ◽  
Author(s):  
M. R. Soltani ◽  
M. Abedi ◽  
R. Askari
Keyword(s):  
Numerical Simulation ◽  
Stokes Equations ◽  
Pressure Fluctuations ◽  
Navier Stokes ◽  
Sustained Oscillation ◽  
Navier Stokes Equations ◽  
Air Intake ◽  
Compression Ramp ◽  
The Difference ◽  
Unsteady Numerical Simulation

Numerical analysis has been conducted to simulate and capture Buzz phenomenon in a supersonic mixed compression air intake. Buzz is an unsteady self-sustained phenomenon occurred in supersonic intakes, especially when operating its subcritical condition, during which the system of compression and shock waves oscillate and move upstream and downstream along the intake. An axisymmetric and unsteady numerical simulation was used to solve Navier-Stokes equations in combination with URANS SST k-ω turbulence model The simulations were performed at M = 2.0 and at a specific subcritical point of the intake operation where buzz was detected experimentally. Results are compared with experimental pressure data. Buzz is captured numerically, and the results show that the buzz oscillation in this intake is periodic, during which the intake duct is loaded and unloaded. The results show that the large separation region on the compression ramp blocks the duct entry and causes the conical and lambda shocks located on the compression ramp to move upstream cause the self-sustained oscillation. The calculated buzz frequency is in agreement with the experimental one, and the difference is less than 0.2%. Further, the peak and trough of both total and static pressure fluctuations, and as a result, the amplitude of buzz are all accurately predicted.

Study on the Refomation of Francis Turbine Based on CFD

2012 ◽  
Vol 516-517 ◽  
pp. 669-672
Author(s):  
Ying Zheng ◽  
Jiu Ju Cai ◽  
Zhan He Ma
Keyword(s):  
Velocity Vector ◽  
Static Pressure ◽  
Stokes Equations ◽  
Francis Turbine ◽  
Navier Stokes ◽  
Lower Efficiency ◽  
Navier Stokes Equations ◽  
Through Flow ◽  
Mesh Method ◽  
Lower Discharge

Based on CFD software, Navier-Stokes equations, Sparlart-Allmaras turbulence model and the structure mesh method, the whole flow passage of Francis turbine were 3-D numerical simulated. By CFView, the distribution of velocity vector and static pressure in the flow passages through flow field were analyzed, which explained the shortcomings of design and its incidental problems of lower discharge capacity and lower efficiency. Consequently the improvement of the runner alone was promoted, and which could be proved to be good results.

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