Computational Fluid Dynamics Analysis Of Axial Flow Pumps

The Characteristics of Axial Flow Pumps

Discuss about the Performance Evaluation Of Power Tiller Operated.

The flow of fluids in axial flow pumps is governed by the partial differential equations which in most cases represents the conservation laws for energy, momentum and mass. CFD refers to the art of substituting such partial differential equations technique with algebraic equations which can be digitally solved using very fast computers (Ahir, 2015, p. 567).

CFD is a branch of fluid mechanics which uses numerical and data structures analysis to solve and analyse problems which involve the flow of fluids. Computers are always used to carry out the computation which is needed to simulate the correlation of liquids and gases which have surfaces that are clearly defined by their boundary conditions. By using high speed supercomputers, it is possible to achieve better simulations (Alexandrov, 2017, p. 43).

CFD offers a quantitative and qualitative prediction of fluid flows by applying mathematical modelling, solution techniques, discretization and software tools such as the pre- processing utilities, post- processing utilities and solvers

Axial flow pumps are very common types of pumps which in most cases comprises of the propeller in a pipe. The propeller is driven by an electric motor or petrol/diesel engines which are fixed to the tube from outside, sealed motor or a right-angled drive shaft which cuts the pipe (Badr, 2015, p. 123). The flow of the fluid particles through the pump don’t change location because the suction change (entry radius) and the exit (discharge) of the pump is small thus the term ‘axial’ pump.

Most of the axial flow pumps have propellers-type of the impeller which runs in the casing. The flow of fluids over the blades of the impeller develops the pressure of the axial flow pump. The fluid which flows through the pump is moved in the direction which is parallel to the impeller shaft (fluid particles) they do not change their radial location when flowing through the pump. Due to that the fluid is allowed to enter the propeller axially or axially discharge the fluid. The axial flow pump propeller is driven by the motor.  (Brandt, 2015, p. 289).

Application of the CFD has a lot of benefits which are associated with it such as:

• In the automotive production Computational fluid dynamics heaps the designers to enhance the aerodynamic characteristics of the vehicles which they produce.
• In architecture, computational fluid mechanics help the architects to come up with designs which are safe and comfortable environments to live in.
• For the industrial and chemical engineering it CFD helps the chemical engineers maximize the output from their equipment.
• Computation fluid dynamics assists the petroleum engineers to come up with optimal oil recovery strategies.
• Computational fluid dynamics helps in the prevention of natural disasters. The meteorologists can be able to use CFD to warn of the natural disasters through weather forecasting (Burrows, 2012, p. 675).
• For safety experts, it helps to reduce health risks from different hazards such radiations.
• Computational fluid dynamics helps the military personnel’s to estimate the damages which can be caused by different weapons and helps in the development of the weapons.
• Accuracy: computational fluid dynamics is an approach which uses the high-speed computers to solve partial differential equations relating to the flow of fluids. In most cases, it involves approximations to discretize the mathematical equations. The applications of CFD in solving problems which are associated with the flow of fluids is very accurate since it involves the use of computers.
• The use of computational fluids is very cost effective: the only coats which are incurred when carrying out computational fluids dynamics are only computing costs and the cost for obtaining a license(Crouse, 2015, p. 76).
• The Computational fluid dynamics is very accessible in that only that is required for you to carry out computational fluid dynamics is a computer. The experiment on
• The other hands are a very elaborate process. The first thing which is needed to be done is to design your model then involve the workshop to assist in fabrications then wait for tunnel time slots.

It is very fast and reliable in that one can be able to turn around much faster as compared to experiments. One can be able to test many models at a go since it involves the use of computers.

The Benefits of Using Computational Fluid Dynamics

The computational fluid dynamics is almost free since what one is required to pay for is only the license for the software as compared to the experiments which will require a lot of resources to be able to be conducted (Dieguez, 2013, p. 173).

Coding is a very important element or tool which one needs to know in general. The Computation fluid dynamics will enable one to obtain the basic understanding of the fluids.

Disadvantages of computational fluid dynamics over experimental work.

For the computational fluid mechanics, not all the models which are generated are reliable some of the models cannot be generated which makes this technique to be very unreliable unlike the experimental methods where the study of the characteristics of the fluids can be easily carried out (Donald M. Sandercock, 2016, p. 253).

When carrying out the simulation of very large simulations, one can require very large and expensive computers which are very hard to acquire.

Axial-flow pumps comprise of a propeller which is confined within a cylindrical casing which is often referred to as propeller pump (Ganis, 2013, p. 76). Below is a well labelled schematic diagram of an axial –flow pump arranged for vertical operations.

Numerical Simulation by use of Computational Fluid Dynamic for the Axial-Flow Water Pump. To determine Complex Turbulent flow.

The axial flow pumps are characterised by huge flow rates and low discharge pressure. Due to those essential features, the axial flow pumps are widely used in different systems such as the municipal water supply, Municipal drainage system, water diversion systems, and irrigation systems and for the major pump for nuclear power plants.

The flow of fluids in axial pumps is very unsteady, complex and fully three-dimensional turbulent. The turbulent flow which is complex as the one mentioned above dominates the characteristics of efficiency, Performance, the vibration of the pump and noise. Nevertheless, many of the physical mechanisms and phenomena which are involved have understood in details up to date, and is considered to be very crucial in better understanding of the mechanisms and physics behind the axial flow pump (García, 2018, p. 107).

The flow of fluids is very complex to be determined using the ordinary experiments because of the pump rotor-stator, which needs CFD numerical simulation methods. In the previous, most of the experimental and numerical studies have been conducted to understand the unsteady flow characteristics inside the axial-flow pumps (Grist, 2011, p. 45). From the experiments which have been carried out the quantities which were always the, parameters which mostly include the pump efficiency and the rate of flow.The diagram below shows the comparison between different impellers (Grondzik, 2015, p. 76).

The Disadvantages of Using Computational Fluid Dynamics

Experimental studies on the axial flow pumps.

The experimental study which was carefully designed on a high-Reynolds-number through different measurements methods which include: calibrated five-hole pressure investigates the determination of stagnation (Badr, 2015, p. 67)

2.0 Measurements of the axial and tangential velocities, by Boraey

To measure tangible and axial velocities of the pump inlet guide and the pump vane exit flow. Tip clearance and rotor blade exist, an oil paint method for visualization of the skin-friction and neighbouring end walls and the rotor blades surface. Very successful feedback was obtained in this experiment by using computational fluid dynamics numerical (Urasak, 2016, p. 896). To understand the complex turbulent flows and came up with ways through which it can be enhanced.

It was noted that from the results of the experiments, the complicated turbulent flow in the experiments that were carried out was limited. This was attributed to the geometry flow passage. Hence the computation fluid dynamics has to be conducted find out the characteristics of the complex turbulent flow. (Thompson, 2017, p. 182).

The computational fluid dynamics which were carried out by Boraey and Mostafa used the K-????model to show as evidence for the effects of turbulent in their calculations of the two-phased flow field around a 3D impeller in a cavitation pump by the use of commercial computational fluid dynamics. In addition to their efforts in carrying out experiments, they used k-???? model. The effects of the inducer which is the interaction of the flow via the inducer (Thomas, 2011, p. 25).

Design of axial flow pumps by application of computation fluid dynamics.

Procedures  for Numerical Simulations

The simulation object which was simulated in his case is the axial flow pump. This is to be carried out with the main objectives to reduce the effects of the boundary conditions and to ensure that the appropriate extensions, numerical stability are perfectly processed at the inlet and the outlet respectively (Taylor, 2016, p. 162).

For one to be able to simulate the actual flow filed and be able to determine any of the asymmetrical flow that can be detected, the whole hydraulic passage of the model-axial flow pump is taken as the computational domain .when accounting for the complexity geometry of the pump and the convince of implementation, from the studies which have been carried out by many researchers they employed the unstructured mesh in the investigation the internal flow of the fluids in the axial flow pumps. Nevertheless, the adoption of the unstructured mesh in thei5 studies led to more grid quantity. And it is impossible to control the grid quality (Syed, 2012, p. 87).

Experimental Studies on Axial Pumps

Accurately. As it is known, the use of turbulence model requires specific range of the wall variable????+ = (????⋅???? ????/]) (where???? is the wall normal distance of the nearest grid away from the wall,] is the kinematic viscosity, and???????? =√????????/???? is the friction velocity with ???????? and ???? being walls hear stress and fluid density, resp.).

The generation of the structured mesh can greatly help in the control of the first layer and the density of the mesh exactly and reduce the grid quantity dramatically as well.

AS the inflow condition, the mass flow rates which are associated with the target for the simulation are specified.  The simulated inlet rate???????? = 305kg/s, head ????=29.5m, and rotating speed ????=2970rpm (Soltis, 2017, p. 87).

 The direction of the absolute velocity vector is axially imposed at the inlet pipe. The inlet pipe at the upstream of the impeller is sufficiently long to develop a velocity profile which is full before the flow enters the impeller.

In practical situations there are non-negligible radial velocities in the real situation, at the front of the impeller there are non-negligible radial velocities that are important for the flow field flow in the impeller. However, due to the difficulties of setting up realistic turbulent inflow conditions, only the mass flow rate and the direction of the velocity are imposed. It is only expected here that the turbulent flow state can be fully developed by the interactions of flow with the solid wall (Slater, 2012, p. 721). Hence the development of the turbulent structures may require an excessive length of the inlet section.

A summary of studies on computational fluid dynamics analysis of axial flow pumps

The aspect of computational fluid dynamics analysis of the Axial flow pumps	Author.
The computational fluid analysis in the axial flow pumps viscous flow in the axial flow pumps impellers. Different studies which have been conducted by different scholars on this topic of the CFD and its relationship with the axial fluids has also been covered well in this journal.	Hirsh and Kang (2001); Shah et al. (2012)
The characteristic performance of the axial pump plus the performance of the axial flow pump and the flow patterns of the impeller. How the performance of the axial flow pump can be enhanced has been greatly discussed by the author. Suggestions on how the axial flow pump can be improved by use of CFD has been explained in details (Sharma, 2016, p. 86).	Maratha et al. (20140; li (2000)
The investigation of the internal flow of the axial flow pump during the design point. The author of the journal gives different suggestions on how the Computational fluid dynamics can be used to improve the flow of the fluids in the axial flow pump before it is being designed (Serovy, 2014, p. 113).	Akhras (2006)
The computational analysis of the mixed flow axial pump impeller. How the computational fluid dynamics can be used accurately to study the different characteristics of the impeller has also been discussed in this journal.	Patel (20130; Kush (2007); Akhtar (2016)
Using the CFD to investigate the Hydraulic design of the axial flow pumps. The different principles which are behind the design of the axial flow pumps have been outlined and the physics or science behind them.	Nagahara (2013);  Kang (2014) and Yang(2009)
The prediction of how the axial flow pump works has also been outlined in this journal, and the author tries to predict how different types of the axial flow pumps (Sayigh, 2015, p. 45).	Dickens chat (2012); Patel 2014
The analysis of the performance of the axial flow pump impeller by using the Computational fluid dynamics and the suggestions on how the performance can be enhanced by using the CFD has also been clearly discussed in this journal/.	Patel and Mehta (2013)
The analysis of the turbulent flow in the impeller of the axial flow pump. The different types of how the fluids flow through the axial flow pump have also been covered in this journal. The causes of the stagnation and change of pressure have also been covered into details (Sabau, 2012, p. 342).	Yang (2007)
Validation and optimization for the axial flow pump. The author of this article tries to explain how the axial flow pump can be optimized to obtain high performance of the axial flow pump.	Prasad (2009)
Computational fluid dynamics based flow analysis of the axial flow pumps. In this article the process on how the CFD can be used to analyse the flow of fluids in the axial flow pump. Different practices which have been carried out by different scholars are discussed in this book. The advantages of CFD over the experimental techniques are also discussed.	Shah (2015)
Reliability and performance enhancement in the manufacture and design of the axial flow pumps. The author of this book explains the different ways on how the performance and reliability of the axial flow pumps can be enhanced by the use of computational fluid dynamics (Miller, 2013, p. 67).	Bagi and Kadam  (2011)
The numerical analysis of the axial flow pump performance characteristics. In this book, the author has tried to explain how the numerical analysis can be used to determine the characteristic performance of the axial flow pumps.	Maratha (2015)
Numerical study of the axial flow pumps impeller with the 2D –curved blades. The author of this journals explains the different studies which have been carried out successfully but various scholars on the topic of the CFD analysis and their relation to the axial flow pump (Jones, 2010, p. 65).	Kush  and Tracy  (2007)
Design optimization of the axial flow pumps and the volume by the application of the computational fluid mechanisms.	Kim et al. (2014)
The simulation of the unsteady flow of the fluids in the axial flow pumps has been discussed in details in this book. The author outlines the major causes of the steady flow of fluids in the axial flow pump and gives suggestions on how the computational fluid dynamics can be used to improve the situation.	Yuliang (2012
Study of the computational dynamics parametric of the geometric variations on the pressure and the characteristic performance of the Axial flow pumps.	Patel (2011)
The analysis of the turbulent flow in the impeller of the axial flow pump. The different types of how the fluids flow through the axial flow pump have also been covered in this journal. The causes of the stagnation and change of pressure have also been covered into details.	Maratha ( 2009)
Computational fluid dynamics based flow analysis of the axial flow pumps. In this article the process on how the CFD can be used to analyse the flow of fluids in the axial flow pump. Different practices which have been carried out by different scholars are discussed in this book. The advantages of CFD over the experimental techniques are also discussed.	Maratha (2015)

Conclusion.

In conclusion, the computational fluid dynamics plays a very important role in the design of the axial flow pumps. It is much easier to study different components of the axial flow pumps.

CFD is a branch of fluid mechanics which uses numerical and data structures analysis to solve and analyse problems which involve the flow of fluids. Computers are always used to carry out the computation which is needed to simulate the correlation of liquids and gases which have surfaces that are clearly defined by their boundary conditions. By using high speed supercomputers, it is possible to achieve better simulations

It is much accurate to study the designs and operations of the axial-flow pumps by the use of the computational fluid

The axial flow pumps are characterised by huge flow rates and low discharge pressure. Due to those essential features, the axial flow pumps are widely used in different systems such as the municipal water supply, Municipal drainage system, water diversion systems, and irrigation systems and for the major pump for nuclear power plants.

Designing Axial Flow Pumps with Computational Fluid Dynamics

There are many benefits which are associated with computational fluid dynamics such as;

Accuracy, computational fluid dynamics is an approach which uses the high-speed computers to solve partial differential equations relating to the flow of fluids.in most cases it involves approximations to discretize the mathematical equations. The applications of CFD in solving problems which are associated with the flow of fluids is very accurate since it involves the use of computers (Kováts, 2014, p. 175).

The use of computational fluids is very cost effective: the only coats which are incurred when carrying out computational fluids dynamics are only computing costs and the cost of obtaining a license.

The Computational fluid dynamics is very accessible in that only that is required for you to carry out computational fluid dynamics is a computer. The experiment on

 The other hands are a very elaborate process. The first thing which is needed to be done is to design your model then involve the workshop to assist in fabrications then wait for tunnel time slots.

Disadvantages of computational fluid dynamics over experimental work include:For the computational fluid mechanics, not all the models which are generated are reliable some of the models cannot be generated which makes this technique to be very unreliable unlike the experimental methods where the study of the characteristics of the fluids can be easily carried out (Donald M. Sandercock, 2016, p. 253).

When carrying out the simulation of very large simulations, one can require very large and expensive computers which are very hard to acquire.

Ahir, V. P., 2015. Performance Evaluation of Power Tiller Operated Direct Driven Axial Flow Pump. 5th ed. Chicago: MPKV, Rahuri.

Alexandrov, N. M., 2017. Multidisciplinary Design Optimization: State of the Art. 5th ed. London: SIAM.

Badr, H. M., 2015. Pumping Machinery Theory and Practice. 4th ed. Texas: on Wiley & Sons.

Brandt, M. J., 2015. Water Supply. 5th ed. Berlin: Butterworth-Heinemann.

Burrows, C. R., 2012. Power Transmission and Motion Control: PTMC. 3rd ed. London: John Wiley & Sons.

Crouse, J. E., 2015. Design and Overall Performance of a Two-stage Axial-flow Pump with a Tandem-row Inlet Stage. 3rd ed. Texas: National Aeronautics and Space Administration.

Dieguez, P. M., 2013. Renewable Hydrogen Technologies: Production, Purification, Storage, Applications, and Safety. 4th ed. Paris: Newnes.

Donald M. Sandercock, 2016. Blade element performance of axial-flow pump rotor with blade tip diffusion factor of 0.66. 4th ed. Merkel: National Aeronautics and Space Administration ; [For sale by the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia.

Summary of Studies on Computational Fluid Dynamics Analysis of Axial Flow Pumps

Ganis, M. L., 2013. CFD Analysis of the Characteristics of a Shrouded Turbine. 1st ed. Chicago: diplom.de.

García, R. N., 2018. Predicting Flow-Induced Acoustics at Near-Stall Conditions in an Automotive Turbocharger Compressor: A Numerical Approach. 7th ed. New Delhi: Springer.

Grist, E., 2011. Cavitation And The Centrifugal Pump: A Guide For Pump Users. 6th ed. Texas: CRC Press,

Grondzik, W. T., 2015. Mechanical and Electrical Equipment for Buildings. 5th ed. Chicago: John Wiley & Sons.

J., S. A., 2013. Centrifugal and Axial Flow Pumps. 6th ed. London: J Wiley and Sons.

James E. Crouse, 2013. Design and Overall Performance of an Axial-flow-pump Rotor with a Blade Tip Diffusion Factor of 0.43. 3rd ed. London: National Aeronautics and Space Administration.

Johnson, W., 2013. Rotorcraft Aeromechanics. Chicago: Cambridge University Press.

Jones, P., 2010. Design and Performance of a 0.9 Hub-tip-ratio Axial Flow Pump Rotor with a Blade-tip Diffusion Factor of 0.63. 4th ed. London: National Aeronautics and Space Administration.

Kováts, A. v., 2014. Design and performance of centrifugal and axial flow pumps and compressors. 6th ed. Chicago: Pergamon Press.

Malkawi, A., 2016. Advanced Building Simulation. 5th ed. Texas: Routledge.

Merke, G. P., 2011. Combustion Engines Development: Mixture Formation, Combustion, Emissions, and Simulation. 7th ed. London: Springer Science & Business Media,

Miller, M. J., 2011. Design and Overall Performance of an Axial-flow Pump Rotor with a Blade-tip Diffusion Factor of 0.66. 4TH ed. London: National Aeronautics and Space Administration.

Miller, M. J., 2013. Summary of design and blade-element performance data for 12 axial-flow pump rotor configurations. 4th ed. Chicago: National Aeronautics and Space Administration.

Nastac, L., 2018. CFD Modeling and Simulation in Materials Processing. 2nd ed. London: Springer,

Pichat, P., 2018. Photon-Involving Purification of Water and Air. 4th ed. Chicago: MDPI,

Rahman, M., 2012. Advances in Fluid Mechanics IX. 3rd ed. Manchester: WIT Press.

Reemsnyder, D. C., 2012. Performance and cavitation damage of an axial-flow pump in 1500 ?F (1089 K) liquid sodium. 5th ed. London: National Aeronautics and Space Administration.

Sabau, A. S., 2012. Twenty-Second Symposium on Naval Hydrodynamics. 2nd ed. Chicago: National Academies Press.

Sayigh, A., 2015. Renewable Energy in the Service of Mankind Vol I: Selected Topics from the World Renewable Energy Congress WREC. 1st ed. Berlin: Springer,

Serovy, G. K., 2014. Prediction of Overall and Blade-element Performance for Axial-flow Pump Configurations, 3rd ed. London: National Aeronautics and Space Administration,

Sharma, A., 2016. Introduction to Computational Fluid Dynamics: Development, Application, and Analysis. 5th ed. London: John Wiley & Sons.

Slater, J. W., 2012. Verification Assessment of Flow Boundary Conditions for CFD Analysis of Supersonic Inlet Flows. 4th ed. Chicago: National Aeronautics and Space Administration.

Soltis, R. F., 2017. Investigation of the performance of an axial-flow-pump stage designed by the blade-element theory - design and overall performance. 2nd ed. London: National Aeronautics and Space Administration.

Syed, A., 2012. Advanced Building Technologies for Sustainability. 2nd ed. Paris: John Wiley & Sons.

Taylor, A. C., 2016. Observations Regarding Use of Advanced CFD Analysis, Sensitivity Analysis, and Design Codes in MDO. 4th ed. Tokyo: Institute for Computer Applications in Science and Engineering, NASA Langley Research Center.

Thomas, B. G., 2011. ASC MSRC Wright Cycles Journal Spring. 1st ed. Texas: DIANE Publishing.

Thompson, J. F., 2017. Handbook of Grid Generation. 3rd ed. Chicago: CRC Press.

Urasak, D. C., 2016. Design and Performance of an 0.8-hub-tip-ratio Axial-flow Pump Rotor with a Blade-tip Diffusion Factor of 0.55. 7th ed. Chicago: National Aeronautics and Space Administration.