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    CFD Modeling for theEstimation of PressureLoss Coefficients of PipeFittings: An UndergraduateProjectKUMAR PERUMAL,1 RAJAMOHAN GANESAN2

    1Department of Chemical Engineering, Curtin University, Miri, Sarawak, Malaysia

    2Department of Mechanical Engineering, Curtin University, Miri, Sarawak, Malaysia

    Received 2 January 2015; accepted 9 August 2015

    ABSTRACT: This work reports the outcomes of a senior undergraduate project done as part of a CFD courseoffered at Curtin University, Malaysia. Pressure loss coefficients for single phase flow through 90 degree bend has

    been estimated using CFD simulation. It is evident from the results that a validated CFD model is a reliable and

    cheap tool forloss coefficient estimation of anycombinationof pipe fittingand complex fluid / flow. 2015 Wiley

    Periodicals, Inc. Comput Appl Eng Educ 24:180185, 2016; View this article online at wileyonlinelibrary.com/journal/

    cae; DOI 10.1002/cae.21695

    Keywords: 90 degree bend; CFD; multiphase flow; pressure loss coefficient

    INTRODUCTION

    Pipe ttings such as valve, bend, tee, elbow, contraction and

    expansion are integral part any piping system found in chemical

    and allied industrial processes. These are mainly used to control

    the ow rate and change thedirectionofow, which causes energy

    loss in addition to that caused by the uid ow through straight

    pipes. Flow ofuids in a piping system is accompanied by both

    skin and form friction, resulting in pressure or energy loss. Skin

    friction, which is responsiblefor pressure lossin straightpipe ow,

    is the friction between the pipe wall and the uid and also between

    the uid layers. Whereas, form friction is caused by pipettings as

    the uid is subjected to sudden velocity and direction changes.

    Reliable pressure loss coefcients for various pipe ttings are

    needed to calculate the additional energy loss and determine the

    correct pump size [1]. The classic reference for such data is the

    Chemical Engineers handbook [2]. Butthis data arelimited to only

    single phase ow of Newtonian uids. Industrial ows are often

    complex involving either multi phases (i.e., solidliquid, gas

    liquidsolid) or non-Newtonian uids. The pressure loss

    coefcients for such uids and ows are not readily available in

    hand books. So there are several attempts by researchers to

    determine these coefcients. In one of the earliest works, Griskey

    and Green [3] determined pressure loss coefcient data for dilatant

    uids. Turian et al.[4] provided loss coefcients for turbulentows

    of concentrated non-Newtonian slurries and Telis-Romero et al. [5]

    presented the data for laminarow of pseudo plastic uids.

    The summary of the published literature is given in Table 1.

    A careful examination of the literature reveals that most of the

    previous work is experimental (E) in nature, which is expensive

    compared to the numerical simulation (CFD) studies. The cost of

    experimental studies further increases when it involves sophisti-

    cated instruments such as Electrical Capacitance Tomography,

    Wire Mesh Sensor Tomography. Because of the low cost, use of

    CFD for the study ofuid mechanics, heat and mass transfer of

    various chemical processes has increased signicantly in the last

    decade or so.

    Computational Fluid Dynamic (CFD) simulations predict

    ow variables such as velocity, pressure ect, by solving the

    mathematical equations describing the relationship between the

    ow variables. So the accuracy of the simulation results depends

    on how well the mathematical model or equations captures the

    ow physics. Theaccuracy of the mathematical model is evaluated

    by comparing the simulation results with the experimental results.

    This process is called validation in CFD parlance. The

    Correspondence to K. Perumal ([email protected]).

    2015 Wiley Periodicals, Inc.

    180

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    Table 1 Summary of Published Literature on Pipe Fittings

    Reference Pipe fitting Fluid Remarks

    Gardner and Neller

    [6]

    908 bend Air water (E), One of the early works in which flow distribution in

    bend was measured experimentally

    Carver [7] 908 bend Air water (CFD), The two dimensional model results did not match

    well with the experimental results of Gardner and Neller

    [12]

    Michaelides and Lai

    [8]

    Return bend Air solid (E), Comparison between experimental and correlation

    predicted pressure drop is good

    Hilgenstock and

    Ernst [9]

    908 bend Single phase (CFD), It is suggested that CFD should be used in

    conjunction with experiments to understand three

    dimensional flow field

    Legius and Van der

    Akker [10]

    908 bend Air water (E & CFD), Good agreement between modelling and

    experiment results has been found

    Pal and Hwang [11] Globe valve, sudden contraction

    and sudden expansion

    Oil in water

    measured emulsion

    (E), Pressure loss coefficients are as function of Reynolds

    number covering laminar and turbulent regimes

    Venkatasubramanian

    et al. [12]

    Bends Coalair (E), Among the tested bends, (Long radius, Short radius and

    Blinded T bend), Blinded T was found to be best for

    pneumatic transport of coal

    Deshpande and

    Barigou [13]

    Sudden contraction and

    sudden expansion

    Gasliquid (E), Presence of pipe fittings in foam flow is found to affect

    the foam structure seriously. This may have foam serious

    practical implications when preservation of foam structure

    is important

    Deshpande and

    Barigou [14]

    Bend, elbow, orifice plate and

    perforated plate

    Gasliquid foam (E), Except orifice plate, all other fittings (bend, elbow,

    perforated plate) introduce large differences in liquid

    holdup and pressure drop gradient between the flows in the

    upstream and downstream pipe sections.

    Polizelli et al. [15] Butterfly valve, plug valve,

    Bend and union

    Xanthan gum (E), Pressure loss coefficients were determined and

    correlated in terms of Reynolds number

    Fester et al. [16] Diaphragm valve Water, glycerol

    and CMC

    (E), Pressure loss coefficients are measured in the laminar,

    transitional and turbulent regimes for valves ranging from

    40 100 mm

    Spedding and

    Bernard [17]

    908 Elbow Gasliquid (E), A general correlation was presented for the elbow bend

    pressure drop in terms of Reynolds numbers

    Spedding et al. [18] 908 Elbow Water oil air Three phase flow is more complex than the two phase flow

    Fester and Slatter

    [19]

    Globe valve Water, glycerol

    and CMC

    (E), Correlation for pressure loss coefficients was developed

    for fully and half open positions

    Liu and Dian [20] 908 bend, gradual and sudden

    contraction

    Coal water slurry (E), It is observed that each fitting has a significant and

    different pressure loss

    Abdulkadir et al. [21] 900 bend Airsilicone oil (E), Flow pattern has been studied using advanced

    instrumentation such as Electrical Capacitance

    Tomography and Wire Mesh Sensor Tomography

    Cabral et al. [22] Butterfly valve, Ball valve, Bend,

    Tee and Union

    Liquid food products (E), Pressure loss coefficients are measured as function of

    generalized Reynolds number covering laminar and

    turbulent regimes

    Kotze et al. [23] Diaphragm valve CMC (E), Velocity profiles are measured using ultrasonic velocity

    profiling technique

    Sharma et al. [24] Rectangular and U Return Bend Oilwater (E), Due to the sharp changes in flow direction, the

    rectangular bend has a higher value of bend pressure drop

    Kaushik et al. [25] Sudden contraction and sudden

    expansion

    Oilwater (CFD), A detailed study has been performed to generate

    profiles of velocity, pressure and volume fraction of phases

    over a wide range of water and oil velocities

    Ma and Zhang [26] Tee, sudden contraction, sudden

    expansion and 908 elbow

    Phase change slurry (E), Correlations for pressure loss coefficients are developed

    using the experimental data

    Alimonti et al. [27] Gate and Globe valve Gasliquid (E) Valve coefficients are determined as function of valve

    openings

    Joyce and Soliman

    [28]

    Tee junction Air water (E) two-phase pressure drop through a horizontal, equal-

    sided, sharpedged, combining tee junction was measured

    and the new experimental data were used to assess the

    performance of existing models

    Nan Lin et al. [29] Elbow Gassolid (CFD) Effect of gas and solid velocity on erosion of elbows

    studied

    Saidj et al. [30] 908 bend Air water (E) Conductance probe technique has been used to study the

    flow pattern upstream and downstream of bend

    Vieira et al. [31] 908 bend Gasliquid (E) Dual wire mesh sensor has been used to study the effect

    of bend on the stratified and annular flow characteristics

    CFD MODELING FOR THE ESTIMATION OF PRESSURE LOSS 181

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    mathematical model is renedtill a reasonable agreement between

    the simulation and experimental results is attained. Such a

    validated model can be used with condence to get a deeper

    insight of the underlying physical mechanisms and to predict

    velocity and phase distribution with high spatial and temporal

    resolution for complex industrial ows [32]. Similar experimental

    studies of such ows are expensive as sophisticated instrumenta-

    tion is needed. Thus, CFD technology is an effective and versatiletool forow predictions if the physical phenomena are adequately

    described by the mathematical model. It should be mentioned here

    that experimental studies are indispensable to get the mathemati-

    cal model validated.

    Recently, Computational Fluid Dynamics (CFD) simulation

    is increasingly being used as a teaching and research tool in the

    undergraduate Mechanical, Chemical and Food Engineering

    courses [3337]. It is either taught as a separate course or used

    in courses like Fluid Mechanics and Heat Transfer to enhance the

    teaching and learning process. It must be noted that CFD is taught

    mostly as an elective course in many universities around the world

    [34]. It is believed that CFD must be made a core part of the

    undergraduate curriculum as it is widely used in the industry and

    academia as a design and optimization tool [3437]. As a teaching

    aid, CFD can make Transport Phenomena education interesting as

    it allows visualization ofow, temperature, pressure and species

    elds [35].

    The objective of this work is to demonstrate the use of CFD

    simulation for the determination of pressure loss coefcients. This

    has been done for single phase Newtonian uid ow through a 90

    degree bend. A good agreement between the simulated and

    empirical loss coefcients gives credibility to CFD simulation for

    its application to multiphase ow predictions.

    CFD MODELING

    Geometry Creation and Grid Independence StudyGeometry creation is the rst step in CFD modelling, which is

    done using a pre-processor. In this work, the 90 degree bend

    (Fig. 1), has been created using the ANSYS Design Modeler.

    Geometry with a total horizontal length of 150 in together with a

    vertical length of 50 in has been designed in order to ensure fully

    developed ow. Grid generation is a key issue in ow simulation

    as it governsthe stability andaccuracy of theow predictions [38].

    Forthe present case ofow througha 90 degree bend, unstructured

    tetrahedral hybrid cells were used to discretize the entire ow

    domain (Fig. 2). Grid independence study was carried out using

    progressively larger number of cell elements. The results of the

    grid independence study is shown in Figure 3. It can be seen that

    there is practically no change in thepressure drop as thenumber of

    grid is increased.

    Governing Equations

    The mass and momentum conservation equations are expressed as

    follows:

    Mass conservation:

    @r

    @t r r~u 0 1

    Momentum conservation:

    @

    @t r~u r ruu~ rp r t 2

    Wherer is the density, u is the velocity, p is the pressure, t is theviscous stress tensor.

    Advanced turbulence models such as Direct Numerical

    Simulation (DNS) can be useful to understand the physics of

    turbulence, but requires powerful computing facility [39]. In this

    work, oneof theRANS turbulencemodels, that is,the realizablek-

    eturbulence model was found to be adequate to model turbulence.

    The k and e equations are as follows:

    @

    @trk @

    @xirkui @

    @xjm mt

    sk

    @k

    @xj

    Gk re 3

    @

    @tre @

    @xireui @

    @xjm mt

    se

    @e

    @xj

    rC1Se C2r e

    2

    k ffiffiffiffiffinep4

    Where Gkrepresents the generation of turbulence kinetic energydue to the meanvelocity gradients,S is themean strain rateand C1,

    C2,skandse arethe model constants.The turbulent viscosity, mt is

    computed as follows:

    mt rCmk2

    e 5

    Where k, e are turbulent kinetic energy and turbulent kinetic

    energy dissipation rate, respectively. Cm is computed from mean

    strain and vorticity rate.

    Figure 1 Geometry of the 90 degree bend.

    Figure 2 Meshed geometry of the 90 degree bend.

    182 PERUMAL AND GANESAN

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    Boundary Conditions

    Water at ambient temperature (300K) was used as the working

    uid. Simulations were carried out by specifying velocity at the

    inlet of the horizontal pipeline. Turbulent intensity, I and the

    hydraulic diameter, Dh were specied for an initial guess of

    turbulent quantities (k and e). The turbulent intensity was

    estimated for each case based on the formula I 0.16(Re)1/8and was about 3% for all the cases. Outow boundary condition

    was used at the outlet boundary.

    Numerical Solution Strategy

    The second-order upwind scheme was used for discretization of

    the convection, turbulent kinetic energy and turbulent kinetic

    energydissipationrate terms.SIMPLE algorithm wasemployed to

    resolve the coupling between velocity and pressure elds.

    The convergence criterion is based on the residual value of

    calculated variables such as mass, velocity components, turbulent

    kinetic energy (k), turbulent kinetic energy dissipation rate (e). In

    the present calculations, the residual values were set at 104

    for allvariables. The under-relaxation factors used for the stability of the

    converged solutions were setat their default values.The numerical

    simulation was decided as converged when the normalized

    residual for each variable was less than the set residual value.

    RESULTS AND DISCUSSION

    In the ow of an incompressible uid through a horizontal section

    of uniform pipe with no work input/output, the mechanical energy

    balance can be written as [40].

    P1 P2rg

    XF

    g 6

    Where P is the static pressure ofow and r is the uid density,

    while the subscripts indicate points 1 and 2, respectively. The term

    F accounts for the friction losses, which include losses in the

    straight pipe section (i.e. skin friction) and from pipettings (i.e.

    form friction) in the system. These can be formulated as

    X F

    X 2fV2LD

    XKfV2

    2 7

    Where f is the Fanning friction factor, which accounts for the skin

    friction loss, V is the average velocity of the uid, L is the pipe

    length and D is the pipe diameter. Kfis the dimensionless pressure

    loss coefcient, which accounts for the form friction. The Fanning

    friction factor is dened as [41]:

    f DPs D2rV2L

    8

    WhereDPsis the pressure loss caused by the straight pipe section

    of length L and Kfis dened as follows:

    Kf2DPf

    rV2 9

    WhereDPfis the pressure loss caused by the pipe tting. A plot

    between DPfand rV2/2 results in a straight line passing through

    origin with Kf as the slope, which is the average value of the

    pressure loss coefcient for the given ow condition. But, for

    accurate determination of pressure loss, knowledge of loss

    coefcient as a function of Reyolds number is essential. Figure 4

    shows the comparison between loss coefcients from simulation

    and published literature.

    Hooper [42] developed an empirical two k method, which

    correlates the loss coefcient with the Reynolds number and the

    diameter of the tting through the following equation.

    Kf K1Re

    K1 1 1D

    10

    The K1and K1 values for the 90 degree bend are taken as

    800 and 0.25 respectively and D is the diameter of the tting in

    inches. It should be noted that this method is applicable only for

    single-phase ow through pipettings. Several authors [15,22]

    have modied this equation for the ow of complex uids and

    ows and estimated the K1 and K1 values for both laminar and

    turbulent regimes. Csizmadia and Hos [43] used experiments and

    CFD modelling to determine the loss coefcient of Bingham and

    Power law uids forow though diffuser and elbows. It can be

    observed that the agreement between the K values is reasonably

    good, particularly for Re

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    better Kfvalues compared to the SST turbulence model used by[43]. From these results, students are able to appreciate the fact

    that a validated CFD model is a very useful tool for the

    determination of pressure loss coefcient of any combination of

    tting and complex uid / ow.

    The powerful post processing tools such as contour plots

    enable students to visualize the contribution of form friction to the

    pressure loss. The drastic change in ow velocity and the

    separation of boundary layer around the bend (as highlighted) can

    be easily observed from the contour plot (Fig. 5).

    CONCLUSIONS

    The usefulness of CFD simulation for the estimation of pressure

    loss coefcients of pipe ttings has been demonstrated through asenior undergraduate project. The results are conclusive that a

    validated CFD model is a cheap alternative for simulating

    complex industrial ows and hence the determination of loss

    coefcients. It is strongly believed that contour plots will help

    students in the visualisation of uid ow phenomena such as

    boundary layer separation.

    REFERENCES

    [1] B. S. Massey, Mechanics ofuids, 2nd ed., Van Nostrand Reinhold,

    London, UK, 1970.

    [2] R. H. Perry and D. W. Green, Perrys chemical engineershand book,

    7th ed., McGraw-Hill, New York, 1997.

    [3] R. G. Griskey and R. G. Green, Flow of dilatants (shear-thickening)

    uids, AIChE J 17 (1971), 725728.

    [4] R. M. Turian, T. W. Ma, F. L. G. Hsu, M. D. J. Sung, and G. W.

    Plackmann, Flow of concentrated slurries: 2. Friction losses in bends,

    ttings, valves and venturi meters, Int J Multiphas Flow 24 (1998),

    243269.

    [5] J. Telis-Romero, M. A. Polizelli, A. L. Gabas, and V. R. N. Telis,

    Friction losses in valves and ttings for viscoplastic uids, Can J

    Chem Eng 83 (2005), 181187.

    [6] G. C. Gardner and P. H. Neller, Phase distributionsow of an air?

    water mixture round bends and past obstructions, Proc Inst Mech

    Engrs 184 (1969), 93101.

    [7] M. B. Carver, Numerical computation of phaseseparationin twouid

    ow, ASME J Fluid Engg 106 (1984), pp. 147153.

    [8] E. E. Michaelides and F. C. Lai, Pressure loss through return bends in

    AirSolidows, Int J Multiphas Flow 13 (1987), 269274.

    [9] A. Hilgenstock and R. Ernst, Analysisof Installationeffectsby means

    of Computational Fluid Dynamics - CFD vs Experiments?, Flow

    Meas lnstrum 7 (1996), 161171.

    [10] H. J .W. M. Legius and H. E. A. van der Akker, Numerical and

    experimental analysis of translational gasliquid pipe ow through a

    vertical bend. In: Proceedings of the 8th International Conference

    Multiphase (BHR) Group, Cannes, France, 1997.

    [11] R. Pal and C. Y. J. Hwang, Loss Coefcients forow of surfactant

    stabilized emulsions through pipecomponents,TransIChemE77 Part

    A (1999), 685691.

    [12] S. Venkatasubramanian, H. Tashiro, G. E. Klinzing, and K.

    Mykelbust, Solids ow behavior in bends: assessing ne solids

    buildup, Powder Tech 113 (2000), 124131.

    [13] N. S. Deshpande and M. Barigou, The ow of gas - liquid foams

    through pipe ttings, Int J Heat Fluid Fl 22 (2001), 94101.

    [14] N. S. Deshpande and M. Barigou, Foam ow phenomena in sudden

    expansions and contractions, Int J Multiphas Flow 27 (2001),

    14631477.

    [15] M. A. Polizelli, F. C. Menegalli, V. R. N. Telis, and J. Telis Romero,

    Frictionlossesin valves andttings forpower lawuids,BrazJ Chem

    Eng 20 (2003), 455463.

    [16] V. G. Fester, D. M. Kazadi, B. M. Mbiya, and P. T. Slatter, Loss

    coefcients forow of Newtonian and non-Newtonianuids through

    diaphragm valves, Chem Eng Res Design 85 (2007), 13141324.

    [17] P. L. Spedding and E. Benard, Gasliquid two phase ow through a

    vertical 908elbow bend, Exp Thermal Fluid Sci 31 (2007), 761769.

    [18] P. L. Spedding, E. Benard, and N. M. Crawford, Fluid ow through a

    vertical to horizontal 90_ elbow bend III three phase ow, Exp

    Thermal Fluid Sci 32 (2008), 827843.

    [19] V. G. Fester and P. T. Slatter, Dynamic similarity for non-Newtonian

    uids in globe valves, Chem Eng Res Design 87 (2009), 291297.

    [20] M. Liu and Y. F. Duan, Resistance properties of coal?water slurry

    owing through local piping ttings, Exp Thermal Fluid Sci 33

    (2009), 828837.

    [21] M. Abdulkadir, D. Zhao, S. Sharaf, L. Abdulkareem, I. S. Lowndes,

    and B. J. Azzopardi, Interrogating theeffectof 90 degree bends on air-

    silicone oil ows using advanced instrumentation, Chem Eng Sci 66

    (2011), 24532467.

    [22] R. A. F. Cabral, V. R. N. Telis, K. J. Park, and J. Telis-Romero,

    Friction losses in valves and ttings for liquid food products, Food

    Bioprod Process 89 (2011), 375382.

    Figure 5 Velocity Contour for Re 10000.

    184 PERUMAL AND GANESAN

  • 7/26/2019 CAE paper

    6/6

    [23] R. Kotze, J. Wiklund, R. Haldenwang, and V. Fester, Measurement

    and analysis of ow behaviour in complex geometries using the

    Ultrasonic Velocity Proling (UVP) technique, Flow Meas Instrum

    22 (2011), 110119.

    [24] M. Sharma, P. Ravi, S. Ghosh,G. Das, andP.K. Das, Hydrodynamics

    of lube oilwaterow through 1808 return bends, Chem Eng Sci 66

    (2011), 44684476.

    [25] V. V. R. Kaushik, S. Ghosh,G. Das, andP. K. Das, CFDsimulationof

    core annular ow through sudden contraction and expansion,J Petroleum Sci Eng 8687 (2012), 153164.

    [26] Z. W. Ma. andP. Zhang, Pressuredrops andloss coefcients ofa phase

    changematerialslurry in pipettings,IntJ Refrig35 (2012), 9921002.

    [27] C. Alimonti, Experimental characterization of globe and gate valves in

    vertical gas - liquidows, Exp Thermal Fluid Sci 54 (2014), 259266.

    [28] G. Joyce and H. M. Soliman, Pressure drop in a horizontal, equal

    sided, sharp edged, combining tee junction with airwaterow, Exp

    Thermal Fluid Sci 55 (2014), 140149.

    [29] N Lin, H-Q Lan, Y-G Xu, Y Cui, and G Barber, Coupled effects

    between solid particles and gas velocities on erosion of elbows in

    Natural gas pipelines, Procedia Eng 102 (2015), 893903.

    [30] F. Saidj, R. Kibboua, A. Azzi, N. Ababou, and B. J. Azzopardi,

    Experimental investigation of air?water two-phase ow through

    vertical 90 degree bend, Exp Thermal Fluid Sci 57 (2014), 226234.

    [31] R. E.Vieira, N.R. Kesana,B. S.Mclaury, S. A.Shirazi,C. F. Torres, E.

    Schleicher, and U. Hampel, Exp Thermal Fluid Sci 59 (2014), 7287.[32] D. H.Zheng, X.He, andD. F. Che, CFDsimulationsof hydrodynamic

    characteristics in a gasliquid vertical upward slug ow, Int J Heat

    Mass Tran 50 (2007), 41514165.

    [33] T. Pujol, L. Montoro, M. Pelegri, and J. R. Gonzalez, Learning

    Hydraulic Turbomachinery with Computational Fluid Dynamics

    (CFD) codes, Comput Appl Eng Educ 21 (2013), 684690.

    [34] S. Aradag, K. Cohen, C. A. Seaver, and T. Mclaughlin, Integration

    of computations and experiments for ow control research with

    undergraduate students, Comput Appl Eng Educ 18 (2010),

    727735.

    [35] J. A. Rabi, R. B. Cordeiro, and A. L. Oliveira, Introducing natural

    convective chilling to food engineering undergraduate freshmen:

    Case studies assisted by CFD simulation and eld visualization,

    Comput Appl Eng Educ 17 (2009), 3443.

    [36] D. M. Fraser, R. Pillay, L. Tjatindi, and J. M. Case, Enhancing theLearning of Fluid Mechanics using Computer Simulations, J Eng

    Educ (2007), 381388.

    [37] F. Stern, T. Xing, D. B. Yarbrough, A. Rothmayer, G. Rajagopalan,

    S. P. Otta, D. Caughey, R. Bhaskaran, S. Smith, B. Hutchings, and S.

    Moeykens, Hands on CFD educational interface for engineering

    courses and laboratories J Eng Educ (2006), 6383.

    [38] P. Kumar, and M. W. Ming Bing, A CFD study of low pressure wet

    gas metering using slotted orice meters, Flow Meas Instrum 22

    (2011), 3342.

    [39] J. Kim, P. Moin, and R. Moser, Turbulence statistics in fully

    developed channel ow at low Reynolds number, J Fluid Mech 177

    (1987), 133166.

    [40] R. Darby, Chemical engineering uid mechanics. 2nd ed Marcel

    Dekker Inc, New York, 2001.

    [41] E. J. Garcia and J. F. Steffe, Comparison of friction factor equations

    for non-Newtonian uids in pipeow, J Food Process Eng 9 (1987),93120.

    [42] W. B. Hooper, TheTwo-KMethod Predicts, Chem Eng24 (1981), 96.

    [43] P. Csizmadia and C. Hos, CFD-based estimation and experiments on

    the loss coefcient for Bingham and power-law uids through

    diffusers and elbows, Comp Fluids 99 (2014), 116123.

    [44] D. S. Miller, Internalow systems, BHRA Fluid Eng (1978).

    BIOGRAPHIES

    Kumar Perumalobtained his PhD degree from

    the University Institute of Chemical Technology

    (UICT), Mumbai, India under the guidance ofPadmabhushan Prof. J.B. Joshi. Kumar is

    currently an associate professor and associate

    Deanfor Teaching and Learningin theFacultyof

    Engineering and Science, Curtin University,

    Sarawak Campus, Malaysia. His research inter-

    ests include Computational Fluid Dynamics

    (CFD), Fluids and Thermal Engineering, Pro-

    cess Intensication Studies, and Engineering Education Research.

    Rajamohan Ganesan is a senior lecturer of

    Mechanical Engineering at Curtin University,

    Sarawak, Malaysia and he obtained his PhD inMechanicalEngineering from Curtin University,

    Perth, Australia. He received his MEng and

    BEng degree fromthe BharathidasanUniversity,

    India. His research interests are production of

    power from low grade heat, mixed convection,

    and radiation heat transfer.

    CFD MODELING FOR THE ESTIMATION OF PRESSURE LOSS 185