To respond to the challenge of agile manufacturing,

companies are striving to provide a large variety of

products at a low cost

Abdullah, Ahmad Baharuddin

Mohd Ripin, Zaidi

Umar, Alias

English

Repository@USM

rAN APPROACH TO PLATFORM DESIGN USING DESIGN AND PERFORMANCE PARAMETERSINTERACTIONSAlias Umar, Zaidi Mohd Ripin and Ahmad Baharuddin AbdullahSchool Of Mechanical EngineeringUniversiti Sains Malaysia, Engineering Campus14300 Nibong Tebal, Pulau Pinange·mail:elyas252@yahoo.comFig.1: Overall process relationship parametersAPPROACHFor a given product, there will be mathematicalequations, which relate main specifications with theoperational parameter and design parameter. Theapproach is show in Fig. 1.develop differentiated product efficiently, increase theflexibility and responsiveness of their manufacturingprocesses, and take a market share away fromcompetitors that develop only one product at time [3].Platform based product development offers a multitudeof benefits including reduced development time andsystem complexity, reduced development and productioncosts, and improved ability to upgrade products.Platforms also promote better learning acrossproducts and can reduce testing and certification ofcomplex products such as aircraft [4], spacecraft [5], andaircraft engines [6]. In the automotive industry, platformsalso enable greater fleXibility between plants andincrease plant usage-sharing underbodies betweenmodels can yield a 50% reduction in capital investment.Firms using a platform-based product developmentapproach in the automotive industry recently gained a5.1 percent market share per year while firms that didnot loss 2.2 percent [7].The objective of this research is to identify therelationship between design parameter, geometry andsystem performance. Modular approaches adopterparameter mapping to identify the platform. In thisresearch centrifugal pump is used as case study.ManufacturingParameta"1 _Original designChanged parameters will bechange perfonnanceSIMBOL-+--.MarketResear<:bKeywords: platform, modules, performance design,platform architecture.INTRODUCTIONToday's marketplace is highly competitive, global andvolatile: customer demands are constantly changing, andthey seek wider varieties of products at the same priceas mass-product goods. This new shift in the market hasincreased the need for product variety, in which varietyand customization replace standardized products [1].To respond the challenge of agile manufacturing,companies are striving to meet the market changesAquirements at a low cost. Especially of modular'-~roducts provides challenges and opportunities for thedesign of assembly systems.Simply stated, a product family is a group of relatedproducts that share common characteristics, which canbe outer features, components, or subsystems. The keyto designing a successful product family is the productplatform. In general, a platform is "the lowest level ofrelevant common technology within a set of products ora product line" [2].Many companies are using platform-based productfamilies that provide sufficient variety for the marketwhile maintaining economies of scale and scope withintheir manufacturing processes. In general terms, aproduct family is a group of related products that isderived from a product platform to satisfy a variety ofmarket niches. By sharing components and productionprocesses across a platform of products, companies canABSTRACTTo respond to the challenge of agile manufacturing,companies are striving to provide a large variety ofproducts at a low cost. The key to a successful productplatform from which it is derived either by adding,removing, or substituting one or more modules to theplatform or by scaling the platform in one or moredimensions to target specific market niches. Theobjective of this study is to investigate effect( -...~erformance parameter to design. Modular approach in"- atform architecture will produce many products from. imited number of components. In this researchcentrifugal pump will be used as case study. In pumpdesign only parameters such as number of impeller,input angle and so will influence product performancefrom the aspect of its shape a form, dimension andgeometry.1All the parameters will be listed and relationshipbetween parameters will be identified via relatedmathematical equations with system or machineintended for design. For cases where, no directequations exist, simulation result from various numericalmethods can also be used. Then matrix interaction fromthat design parameter is build.Matrix interaction will give the entire relationshipbetween, specification parameter, operation and design.Interaction value will be determined based on themathematical equation, which indicates the parameterseffect on each other. For example:f1 =QH/P,Where,f1 = efficiencyH = headQ = flow rateH=P-j/2gWhere,P =powerv = velocityg =specific gravityCASE STUDYIn this study a centrifugal pump is selected for casestudy as shown in Figure 4.The interaction in the interaction matrix as in Figure_~2. Parameters which have no relationship will be marked( Jzero.f1 v Q H Pf1 X 1 1 -1v X 2Q 1 XH 1 2 X 1P -1 1 XFig. 2: Construction matrix interactionFig 4: Cross section of centrifugal pumpCOMPONENTSBasically centrifugal pump consist of seven majorcomponents as follows.i. Impellerii. Voluteiii. Casingiv. Shaftv. Sealvi. Bearingsvii. Oil sealsFig. 3: Cluster effect on matrix interactiona). ImpellerThe selection of impeller design is mainly based on thespecific speed as reproduced below based on thespecific speed as reproduced below based on the workby [11].From those performance Q,H, P and f1 are outputparameters where N is the input parameter to the system(N is the motor output)Pump PerformanceIn measuring pump performance, there are 5 majorparameters that have influence on pump performance[10].i. Flow rate - Qii. Head- Hiii. Input power - Piv. Efficiency - f1v. Speed - NThree components that greatly influence the pumpperformance are the impeller, casing and which directlyin which influencing the pressure and flow rate [10] and[11 ].~ Component AIII Component BhfXX-~.x,cFrom there the parameters can be clustered withhighest interaction density by using TriangularizationAlgorithm [8].Followed by mapping between clustered parameterswith components related with those parameters. Suchas, N (pump revolution speed), f1 (pump efficiency),H(head), and z (no. of vanes) are related with impellerand volute. Interaction density can be used to identifywhich component is more relevant. Figure 3 belowindicates matrix interaction and module identified.nab ca XbAnd finally is the new design based on the interactionfor future upgrade machine by platform design and thedesign is subjected to further calculation.Flow rate, Q is:Q= AV (1)2EFFICIENCY VALUES FOR PUMP WITH OiFFEAEN-TSPECIFIC SPEEDSFig. 5 show the "Maximum practically attainableefficiencies pumps dependent on specific speedand rates flow.(5)b). ShaftReferring to torque required from the shaft to the impellerthe relationship is as follows.3 16 ~ 2 2d = - (K b M b) + (KtM t)1tSsWhere,Ss - AllowableMb • bending momentMt _ torsional momentKb - fatigue factor (bending moment)Kt - fatigue factor (torsional moment)And rating life for ball bearings L, as give by the followingequation:L =(C/P)3 million revolutions (6)Where.P = the equivalent loadC = basic load ratingc). CasingThe effect of casing on the overall performance cannotbe represented directly using design equations. Thereare some design guidelines which indicate the thicknessof casing based on the pressure.INITIAL RESULT AND DISCUSSIONIn the present work to early steps in study have beencarried out, which identifying design parameters andmatrix interaction is mapping. From this mapping. therelationship between parameters that influence design aproduct performance can be determined easily based onoptimum customer requirement as show Fig. 6. Forinstance, jf customer gives specification in the form ofhead (m) or matrix interaction. As example. theinteraction relationship between head (m) and D(diameter of impeller) are 0.5, because the relationshipbetween two parameters is 0.5. Fig. 7 indicates thematrix interaction.Mathematical model for these curves with the aid ofregression. The efficiency '1, curve via regression isapproximated as [12]:'1 = -8.84553 X 10.3 + (7.9485 x 10·2)Ns - (4.0913x 10·3)Ns2 + (1.08499 x 10"dNS - (1.40755 x10·6)Ns4 + (5.497 x 10·9)Ns + (4.07879 x 10'11)Ns6 _ (2.66217 X 10'13)Ns7And input power from torque and speedP = T(21tN)/60 [Watt] (4)From the above formula/equation shaft parameters canbe found.(2)...---...- 10 "pm______ 30gpm., }o(-.-_ , 100gpm'-iIf-200gpm____ 1000 "pm_3000gpmSpecific .p •• d (Ns,_ __,,-.m,. .._--~'-~8 '.10 Jf/i .... l-----,irlF'------------j'" I::; •. so ,',," II... 11'where.Q-f1ow rate (Q =m3/s)A - cross section area (mm2)V- velocity (mls)And head, His,H = '1H {UNu2 - UN U1)/gWhere,'1H -fluid efficiency (0.85 - 0.95)1 -Input2 - OutputPump efficiency '1.vQH1] =-- (3)PWhere,v - Specific speedQ - Flow rateH -HeadP -PowerFrom a user's perspective optimum hydraulic designis synonymous with optimum efficiency. A less obvious,(~t well established fact is that optimum hydraulic design,,,-,J also, in general, synonymous with improved reliability.As a rule, increased hydraulic efficiency results inreduced hydraulic disturbance and since the forcestransmitted to the bearings are Virtually all hydraulicallygenerated, an optimized hydraulic design will minimizethese forces. This results in reduced shaft deflection andreduced bearing loads which, in turn. leads to improvedlife of mechanical seals and bearings. The key toinherently reliable and efficient pumps therefore lies inthe hydraulic design.Probably the most significant development tofacilitate the optimization of hydraulic designs is theavailability of reliable, variable speed motors. Particularlyfor pumps of low specific speed and inherently lowefficiency, there is now the opportunity to operate super-synchronously with the corresponding improvements inefficiency.3I Nsslimit I ·1.33 L NPSHR o 7I r r I Ns ~1.33 t I I1L J rpm r"~~I I ~rpm limit -oJ 5 Q I II Ns No.imp.--.~ p-- ..... I II.75 HI 0.5.sII NPSHA I I Suc.type I ·1II Efficiency II I..oL-I-0.5J II I I J I VlIIles angle, PHyd.KW Specific gravity,R..-II' I No. ofvanes, Z-I I Impeller dia. d Af.I IFig. 6: Construction parameter digraphINPUT OUTPUT IMPELLER OIA.':ml H(m) Q(m',s) sg NPSHA Nss z Ns q HydkW BHP NPSHR Ns.... rpm.,. cm3 u2 fJ"dN(rpml x 1 1 1.33 -1Hm X -0.75 1 0.5i Om/s X 0.5 0.5 1 0.67 -Q.5~ sa X 1NPSHA X 0.75Nss 1 0.5 X 0.75z X ·1! Ns 1 .0.75 0.5 X 1 -1" X -1 -0.5H\I<lkW 1 1 1 -I XBHP XNPSHR 1.33 0.67 -0.75 X -1.33Ns.... -1.33 X 1mm. -0.5 0.75 1 Xlr cm3 1 X 1w.... u2 0.5-1 -0.5 1 X 0.5 -0.5 1....~$ 8 -0.5 0.5 X 1-0 /l -1 -0.5 1 Xd -1 1 XFig. 7: MatriX InteractionCONCLUSION~, The objective of this study is to identify module whichC. lith certain product design parameter variation change,performance can be increased. For now, pump designparameters have been identified and the interactionmapped.REFERENCES1. Siddique. Z., Rosen, D.W. and Wang, N., On theApplicability of Product Variety Design Concepts toAutomotive Platform Commonality, Design Theoryand Methodology, Atlanta, GA, ASME, Paper No.DETC98/DTM-5661 (998).2. McGrath, M. E., Product Strategy for High-Technology Companies, Irwin ProfessionalPublishing, New York. NY (1995).3. Robertson, D. And Ulrich, K. "Planning ProductPlatforms," Sloan Management Review, 39(4), pp.19-31 (1998).4. Sabbagh, K., Twenty -First Century Jet: Themarking and Marketing of the Boeing 777, Scriber,New York, NY (1996).5. Caffrey, R. T., Simpson, T. W., Henderson, R. AndCrawley, E., The Technical issues withImplementing Open Avionics Platform forSpacecraft, 40th AIAA Aerospace Sciences Meetingand Exhibits ,Reno, NV, AIAA-2002"()319 (2002).6. Rotwell,R., Gardiner, P., and Robustness, ProductDesign Families, Design Management: A handbookof Issues and Methods M. Oakley. ed., BasilBlackwell Inc., Cambridge, MA, pp. 279-292 (1990).47. Cusumano, M.A. and Nobeoka, K., ThinkingBeyond Lean, The Free Press, New York, NY(1988).8. Kusiak, A., 1994. Concurrent engineering Issues,models, and solution approaches, Handbook ofDesign, Manufacturing and Automation, Eds. NewYork. Pp 35-49.9. Hall, A.S., Alfred R., Holowenko, and Gilbert, H.,Theory and Problem of Machine Design, McGraw·Hill, U.S.A (1980).10. Karassik, I.J., Messina, J.P., Cooper P., Heald, C.,.Pump Handbook, McGraw-Hili, U.S.A.( 2001).11. Igor J. Karassik, Joseph P. Messina, Paul cooper,charles C. Heald, (2001), "Pump Handbook",McGraw-Hili, U.S.A.(~)2. Rishel, J.B., Water Pumps and Pumping Systems,'"'-~' McGraw·Hill, U.S.A. (2002).5

An Approach To Platform Design Using Design And Performance parameters Interactions.

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An Approach To Platform Design Using Design And Performance parameters Interactions.

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