Imperial Journal of Interdisciplinary Research (IIR) Vol-3, ssue-1, 2017 ISSN: 2454-1362, http://www.onlinejournal.in CFD Analysis of Butterfly Valve by Using FEA Tushar Shinde’, Santosh Wankhade* MLE. Machine Design, Department of Mechanical Engineering, YTIET 3HOD, Department of Mechanical Engineering, YTIET Abstract: A butterfly valve is a type of flow control device, which is widely used to regulate the fluid flow in a pipe section. Studies on flow behavior in valves have led to continued effort on optimizing the valve design. navier stokes equations are solved numerically t0 predict the flow behavior and flow coefficient. The ‘present work aims 10 study the effect of pressure drop, flow coefficient, loss coefficient and flow behavior across different valve design. Based on the baseline simulation results, optimized design is suggested. 3D, steady, incompressible, turbulent kee 1. Introduction Buttery valves are commonly used in industial applications to control the internal flow of both ‘compressible and incompressible fluids. A butterfly valve typically consists of a metal dise formed around a central shall, which acts as its axis of rotation, As the valve's opening angle, 0, is inereased from 0° (fully closed) to 90° (fully open), Muid is able t© more readily flow past the valve, Buttery valves must be able to withstand the stresses and forces that results from high Reynolds number flows. (Characterizing a valve's performance factors, such as pressure drop, hydrodynamic torque, flow ‘coefficient, loss coefficient, and torque coefficient, is necessary for fuid system designers to account for system requirements to properly operate the valve and prevent permanent damage {rom occurring to the valve. This study compare a 48-inch buttery valve's performance factors oblained using Computational Fluid Dynamics (CFD) and to assess the feasibility 3. METHODOLOGY ‘The proposed work shall include following steps: 1. Study of literature review of various work reported, 2 Geometric modelling of Butterfly valves having different shapes such as Symmetric Shaped valve and Asymamettic shaped valve CED analysis for each of the above geometry for different opening and closing angle in upstream and downstream flow. 4. Comparison of the result obtained in above step. 5. Choosing the optimam design based on Flow coefficient & loss coefficient. Flow characteristics around the butterfly valve ‘considering various disc shapes would give insight idea of their performance so that comparative results ‘could be made 4. CFD MODEL ‘Three different geometries of 48-inch flow regulating valve, Model, Model-l and Model-II in fully open condition as shown in Fig.5.1, 8.2, 5.3 respectively ‘considered for the present analysis. The design parameters such as diameter of dise, thickness and shaft rod diameter shown in table as below 4.1 MODEL ¢ Model is taken as a baseline design for an analysis and itis created by using ANSYS workbench geometry module. The shape of this dise is flat from both front and back side and stem of the ‘of using CFD to predict performance factors of Dutery valves 2. OBJECTIVE ‘The proposed work shall include the modelling of different types of butterfly valve using commercial software. The geometrical model shall he prepared for the varied geometrical parameter ke plate thickness, size of dise and dise diameter ete > To analyse the flow field (characteristics) around the butterfly valve for the various ‘opening angles. ‘MODEL- | MODEL MOPEL-UL 1 1 Dire Diameter,D | 1200 | 1200 120 am) Tiida t ToOeeaey so 30 am S0(outer edge) halted diameter, é | 100 10 0 (om) > To analyse the performance of buterfly valve by considering the dise shapes. Tiss Isto the downstream side, The thickness of the disc i 50 mm and it is changed in second model Imperial Journal of Interdisciplinary Research (1IR) Page 1832Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-1, 2017 ISSN: 2454-1362, http://www.onlinejournal.n which we can call as optimised model. The model- I is shwon in | 1 “Figure 1. Model-I(Bascine Design 4.2 MODEL II ‘Modell is created by optimising the shape of the ‘model-I which we had taken as baseline design for analysis, In the Model-II valve, dise thickness reduced from 50 mm to 30 mu and disc profile made ‘convex from both sides. In addition, the shaft rod diameter reduced from 100 mm to 70 mm. The ‘model- II is designed by optimizing the Model-I so we can call it as Optimised Design of valve and is shwwon in | 2. “Figue 2 Mode/-li (Optimised Desiga)™ 4.3 MODEL I In designing the Model-IIl the Model -Il is taken as base design for optimisation. The disc shape of ‘Model-Illis ike cone from one side and flat from ‘other side. The centee thickness of the cone is 100 ‘mm and the thickness at outer edge is 30 mm. The ‘model-IT is shwon in Fig 3. v7 “Figure 3. Modell Final Optimised Desiga)™ 5. MESHING In the present work, unstructured tetrahedral clements with high density near the valve seat region and prisms at near-wall to capture the wall Y= are created using ANSYS Fluent. Flow domain is ‘extended fo 2D on the upstream side and 6D on the downstream side to improve the flow field at shown - “Figure 4, Meshed assembly of valve ie and pip “Figure 5. Meshing view of Mode! dise™ “Figure 6 Meshing view of ModeL.I dite” “Figure 7 Meshing view of ModeV-IT dise 6. BOUNDARY CONDITIONS In three dimensions, boundaries are surfaces that completely surround and define a region. Each boundary has its own properties and can be given ‘custom configurations such as meshing surface size, ‘or how it should behave relative to other surfaces. ‘The main boundary types chosen were the following: ‘wall, intemal interface, velocity inlet, and flow ‘outlet, These boundaries and their corresponding ‘chosen surfaces for this study, will now be discussed, Imperial Journal of Interdisciplinary Research (1IR) Page 1833,Imperial Journal of Interdisciplinary Research (IIR) Vol-3, Issue-1, 2017 Isr 2454-1362, http://wwmw.onlinejournal.in Velouiy al) 26 “Temperature 05) 288.16 Viscosity tegim-s) ‘0.001003 Py “Figure 8, Ietrtion of boundaries and components ofthe buttery valve simslations” 6.1 WALL ‘A wall boundary represents an impermeable surface. For simulations with viscous flow such as this one, it also represents a no-slip boundary. All of the following surfaces were chosen as wall boundaries ‘except: the upstieam inlet face, the downstream ‘outlet face, and the interface connecting the downstream cylinder to the extruded cylinder portion as seen in Fig, All valve faces were assumed to be smooth therefore required no modifications to surface roughness. All other wall roughness parameters were left as default 6.2 VELOCITY INLET ‘A velocity inlet boundary repretents the inlet of a ‘duet at which the flow velocity is known, The upstream cylinder inlet face was selected at such For the velocity inlet boundary, the velocity must be specified by the user, as well as the turbulent dissipation rate and the turbulent kinetic energy When using the k- € turbulence model, which was the ‘case inthis study 6.3 FLOW OUTLET ‘The flow oullet boundary represents the oullet of a ‘duct and can allow flow split fractions in which the user can specify the percentage of flow leaving ‘multiple ducts. In this study, that value is set to unity for the downstream outlet face of the extruded cylinder. Additionally, flow properties such as velocity, turbulence qualities, etc. are forced to have ‘zero gradients normal tothe outflow face. In order to properly apply this boundary condition, the pipe Tength downstream fom the installed buttery valve rust be long enough that the flow has become fully developed 40 a# not to prematurely force the flow to zero gradient condition, 6.4 FLUID: WATER LIQUID ‘The fluid for a CFD analysis is taken as liquid water whose properties are shown in Table Density (kg/m) WEE “Table T Properties of igus water™ 7. RESULT, For the 1S-degree open cases, high pressure is ‘observed in the small gap between the valve disk and the pipe wall as shown in Fig. A large pressure drop ‘across the valve is also observed in the Model-T ‘compared with Model-If and Model-ll, The velocity vectors in Fig. show swirling and rotational flow ‘bchind the valve disk, with large eddies present “Fig 9. Pressure of battery vavle for 15 degree open in ‘model 1." ig 10 Pressure of butery vave for 18 degree open in ‘model 2, “Fig 1 Pressure of buttery vale for 15 degree open in ‘model 3." “Fig 12.Velocty vector of buttery vale for 15 degre open ‘in model Imperial Journal of Interdisciplinary Research (1IR) Page 1834Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-1, 2017 ISSN: 2454-1362, http://www.onlinejournal.n Comparison of loss coefficient results between the MODELS-1 If & IIL Loss Coefficient Ky (Gimenstontess) Angle, 8 soni (ée) | MopELt | Mopetat | MCD! “Fig 13 Velocity vector of buttery vave for 15 degree open TE ee | ATT TATED ‘in mode! 2. 3034-61531 | 20.362 | 13.60113 45 | 9.672023 [3.97448 | 4.47448 60 | 2.42185 [1.689036 | 1.640685 90 [051811 [0.168998 | 0.168989 “Fig Ld Velocity vector of buttery in model 3 se for 15 degtee open Comparison of pressure drop results hetween the ‘MODEL. UI “Table 5: Compatison of loss couisient ress 8. CONCLUSION ‘Numerical simulation is carried out to predict the flow bebavior across the low regulating butterfly valve. Three different designs (Model-L, Model, ‘Model-IIT) are considered for the simulation. The following are the observations made: (_ 2) MODEL MODEL. | MODELET (7 ooros2 | oor00s7 | o00sai (30 oss 00802 0051481 (ss oossst_ [0.075302 0.070683 er 0.122001 | 0.215817 _| 0.240278 30 0.12379 [0.00167 [0.035598 “Table Comparton of Torque eoelicent resi Pressure loss, AP *10° (Pa) Angle, 0 MODEL] * Flow behavior is predicted in terms of pressure, es) [Mops | mone | MOP ely a esis plot 1s 235576 | 207.82 174.29) It is seen that in Model, large 30 [ae [aise | ae teckelanagnaion repo devo i te downten si of te ave due the a | was | oaer | are preva em oo 2.562) 1787 17358 >» Flow coefficient increases by 31.56% in of esis [aire [oar |” Mali a compart wath Modtt a 43 “Table 2 Comparison of pressure drop resus degree opening. scion of Sow srtcient ents vera te HYMN tn coefak.see to Sapper of Dow coricent eat between te” Ne ferreting te dee Moe a i deugn dtr te opening of Angle, @ = valve Wes) [Mover | wopetan sores > ass Concent get reused in unas [Oana | SAE * 13,7962 | 16.64369 | 20.15091 > The present optimized design (Model-II}) helps | so.o6sos | 33.5462 | 35.3141 | in improving the flow field, flow coetficient 67.72698_[_117.3657_| 118.4531 ‘and reduces manufacturing cost. Pr Chapa ow ie Comparison of tre confi ets bss he MODELS-1, If & II 9. REFRENCES 1) Zachary Leutwyler, Charles Dalton in the paper lille “A CFD Study to Analyze the Aerodynamic Torque, Lift, and Drag Forces for a Buterfly Valve in the Mid-Stroke Position” reported in the journal of| the ASME Heat Transfer/Fluids Engineering ‘Summer Conference, 2004. [2Vanusz Wojtkowiak, Czeslaw Oleskowiez~ Popielin the paper title “Investigations of Butterfly ‘Control Valve Flow Characteristics” reported in the Impe Journal of Interdisciplinary Research (IIR) Page 1835,Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-1, 2017 ISSN: 2454-1362, http://www.onlinejournal.n journal of the Foundation of Civil and Environment Engineering, No.7, ISSN 1642-9303, 2006 BID. Henderso, J. E. Sargison, G. J. Walkers J. “Haynes in the paper ttle “A Numerical Study of The Flow through a Safety Butterfly Valve in a Hydro- Electric Power Scheme” reported in the 16th ‘Australasian Fluid Mechanies Conference, 2007. [2]Weerachai Chaiworapuek in the paper title “The Engineering Investigation of The Water Flow Past the Butterfly valve” reported in Erasmus Mundus ‘Master of Mechanical Engineering Memoite-Thesis, 2007, Imperial Journal of Interdisciplinary Research (1IR) Page 1836