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3D Inviscid Inverse Design Code Applicable to All Types of Axial, Mixed Flow and Radial Turbomachinery

Competitive Advantages of TURBOdesign1

Significant manpower and design-time savings2-3 times improvement in productivity per designer.

Good designs with little prior design experience TURBOdesign1 does not rely on empiricism and hence it is very easy to train new designers/users who can become productive very quickly.

Performance Improvement• Typicalimprovementsoftheorderof2-3pointscanbeobtainedover

the best of state-of-art-design.• Significantsuctionperformanceimprovementinpumpsand

turbopump inducers.• Significantimprovementinfannoise.

Innovative designs Beyond previous ExperienceTURBOdesign1 allows designers to access larger part of design space with ease, thereby allowing breakthrough designs. It has been used for• Secondaryflowsuppressionandjet/wakeflowminimisationinradialimpellers.• Suppressionofcornerseparationinvaneddiffusersforpumpsandcentrifugalcompressors.• Reduction of endwall losses in axial turbine stators without any increase in loss at mid-passage. • Control of separation and secondary flows in torque converter pump and turbine impellers. • Control of rotating cavitation in turbopump inducers.

Database of Design Know-how and its TransferOptimum blade loading for a particular application is quite general and can be applied with ease to similar applications. The results of design optimization studies can be easily implemented in a design database that be transferred between different design teams in the organisation or to help train new designers.

Fig. 1: Conventional or direct design method relies on trial and error and the experience of designer in order to achieve desired power or torque and pressure ratio as well as efficiency.

Fig. 2: In TURBOdesign1 the blade geometry is computed for specified blade loading. The resulting blade geometry will not only meet the required targets for pressure ratio, torque and power but it will also provide higher performance.

Basic Features of TURBOdesign1TURBOdesign1 computes the 3D blade geometry for a given distributionofbladeloadingandbladenormalthickness.Specifyingblade loading gives direct control over the 3D pressure distribution and the spanwise work distribution. It allows for direct control of the 3D flow field and allows designers to explore a large part of design space efficiently leading to breakthrough designs. It results in significant improvement in performance as well as reduction in design and development times.

Inverse Design versus Conventional DesignThere are two methods for aerodynamic design. In the direct method, commonly used in turbomachinery design, the blade geometry from earlier designs is specified and then modified iteratively by trial and error using a Computational Fluid Dynamics (CFD) code to evaluate each design and in order to check whether the required flow field in terms of pressure distribution, torque and pressure ratio is obtained (see Fig. 1). This approach to a large extent relies on empiricism. In the inverse design method, the blade geometry is computed for a specified distribution of blade pressure distribution, which controls the overall behaviour of the flow on the blade.

©2016 All rights reserved. Advanced Design Technology Ltd

Advanced Design Technology LtdDilke House 1 Malet Street London WC1E 7JN United KingdomPhone +44 (0) 20 7299 1170Fax +44 (0) 20 7636 8028sales@adtechnology.co.uk www.adtechnology.co.uk©1998-2011 All rights reserved. TURBOdesign® is a registered trademark of Advanced Design Technology Ltd

Design Process

Step1: Basic Inputs• Inputthe initialmeridionalshapebasedon1Dsizingcode.

This can be modified within TURBOdesign1

• Inputtherpm,volumeflowrateorinletvelocitydistribution

• Inputthenormalthicknessdistribution

Step 2: Main Design ParametersInput the spanwise rVθ distribution at inlet and exit to blade row.

Free vortex and non-free vortex distribution can be specified.

This step fixes the specified work.

Input the blade loading distribution based on the main design

objectives (seeopposite). Thisdistributioncanbe fine tuned

later.

Input the stacking location and distribution along a quasi-

orthogonal between leading and trailing edges. This will be used

as initial condition to compute the blade shape that satisfies the

loading distribution and spanwise work distribution.

Step 3: Fine Tuning Specified Blade Loading• TURBOdesign1 not only computes the blade shape but it

also provides an accurate prediction of blade surface velocity,

Mach number or static pressure distribution ( see Fig. 3).

• Full3Dsolutionisobtainedinlessthan30secondsonasingle

core of PC.

• SurfacevelocityorMachnumber isused tocheck the flow

diffusion (or static pressure is used to check for cavitation)

and make any necessarily changes to loading to fine tune the

design.

Step 4: Off Design Prediction by CFDOnce the loading is fine tuned, CFD is used to evaluate the off-

design performance of the design.

References:Goto,AandZangeneh,M,(2002),“HydrodynamicdesignofpumpdiffuserusingInversedesignandCFD”,ASMEJournalofFluidsEngineering,Vol124,pp319-328.Bonaiuti,D, Zangeneh,M,Aartojarvi, A, Eriksson, J, (2010)“ParametricDesignof aWaterjet PumpbyMeansofInverseDesign,CFDCalculationsandExperimentalAnalyses”ASMEurnalofFluidsEngineering,Vol 132.Zangeneh,M.,Goto,AandHarada,H.,(1998)”OnthedesigncriteriaforsuppressionofsecondaryflowsinCentrifugalandMixedflowimpellers”ASMEjournalofTurbomachinery,Vol120,pp.723-735.

The above type of blade loading in which there is little shroud loading in the first10%ofchordfollowedbyfore loading results in good suction performance and efficiency. This type of loading has been found to have generality.SeeBonaiutietal(2010).

Blade loading specified was fore-loading at the hub and aft-loading at the shroud. This type of loading helped to remove corner separation in pump vaned bowl diffusers as well as centrifugal compressor vaned diffusers. See Goto and Zangeneh(2002)forfurtherdetails.

Blade loading specified was fore-loading at the shroud and aft-loading at the hub. This type of loading was found to be generally applicable to pumps and centrifugal compressors proved effective. For further details seeZangenehetal(1998).

ExamplesofChoiceofBladeloadingSecondary Flow Suppression for Radial Impellers

Improving Suction Performance with minimum Efficiency Loss

Suppression of Corner Separation in Vaned Diffusers

Conventional TURBOdesign1

Fig. 3: Comparison of surface static pressure from TURBOdesign1 with 3D CFD for a centrifugal fan.

Conventional

TURBOdesign1

Advanced Design Technology LtdDilke House, 1 Malet Street, London WC1E 7JN United KingdomPhone +44 (0) 20 7299 1170Fax +44 (0) 20 7636 8028Sales@adtechnology.co.ukwww.adtechnology.co.uk©2016 All rights reserved. TURBOdesign® is a registered trademark of Advanced Design Technology Ltd