Several Examples of Turbomachinery Design and … Examples of Turbomachinery Design and CFD-Simulation ... CATIA, Creo, UG NX, SolidWorks, SpaceClaim, … Production Computation, optimization:

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Several Examples of TurbomachineryDesign and CFD-Simulation using

CFturbo® and STAR CCM+®

Dipl.-Ing. Ralph Peter Mueller CFturbo Software & Engineering GmbH Munich, Germany


Several Examples of Turbomachinery Design and CFD-Simulation using CFturbo® and STAR CCM+

CFturbo® Software & Engineering GmbH

Engineering CAD & Prototyping

• Turbomachinery Conceptual Design

• CFD/FEA Simulation

• Optimization

• 3D-CAD Modeling

• Prototyping

• Testing, Validation

CFturbo® Software

• Turbomachinery Design Software

• Automated Workflows

Company



ConceptualDesign

CFturbo®

Meshing, CFD-Simulation, Post-ProcessingSTAR CCM+

3D-CADCATIA, Creo, UG NX,

SolidWorks, SpaceClaim, …

ProductionComputation, optimization:interactively or automated

ExperimentsPrototyping, Testing,

Validation, …

Turbomachinery Design Process



Manual „Optimization“ Workflow

Transsonic Radial CompressorTraditional common workflow: 5 … 25 model variations, 1 to 4 weeks,

Design point (BEP)Total pressure ratio: ∏tt = 4Mass flow rate: ṁ = 0.11 kg/sSpeed: n = 90.000 min-1

Power (limitation): Pm < 30 kW

20 Designs 20 Performance Curves 1 Prototype



Automated Optimization Workflow Available

HEEDS

PerformanceDesign goals

Optimization

CCM+CFturbo

Centrifugal Pump Impeller Optimization300 automated model variations, time & cost depending on available resources



CFturbo Model Overview Pumps



CFturbo Model Overview Compressors, Turbines



CFturbo Model Overview Fans, Blowers



Example 1. Radial Pump with Inducer

Comments- Generic CFturbo design, 5 design variations- Q=600 m³/h, P=120 bar, n=12000 rpm- Compare CFD-simulation

• Steady State, no cavitation• Transient flow, no cavitation• Transient flow, with cavitation

- No experimental are data available






0.2

0.4

0.6

0.8

1

1.2

1.4

0.4 0.6 0.8 1 1.2 1.4 1.6

Hea

d / H

ea

d D

es

ign

Po

int

Flow Rate / Flow Rate Design Point

steady state w/o cavitation

transient w/o cavitation

transient w/ cavitation

Design Point



,


Volume Flow, Vapor Fraction

,

He

ad P

ress

ure

• Rising vapor fraction determines lower pressure• Transient flow simuation with cavitation modeling is

essential for NPSH calculations



Example 2. Initial Design Axial Pump

- Typical design point for axial pump defined- First initial conceptual design by CFturbo- No diffuser or inlet guide vane. Rotor in pipe.

• n = 780 rpm• H = 15.6 feet• Q = 23,400 gpm• NPSHr = 27 feet• Tip diameter = 23 inches• Shroud diameter = 23.25 inches• 0.3 hub/tip ratio

- Steady state & transient Simulation, - Cavitation



Example 2. Initial Design Axial Pump

Leading edge blade tip cavitation



0

10000

20000

30000

40000

50000

60000

70000

80000

90000

400 900 1400 1900 2400

Dp

to

tal [

Pa]

Massflow [kg/s]

steady state transient transient with Cavitation model

Steep performance curve with saddle point, that is typical for axial pumps



0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

effi

cie

ncy

[-]

MassFlow [kg/s]

transient stady state transient with Cavitation model

Very first initial design >> hydraulic efficiency should be significantly improved



Example 3. Radial BlowerComments- Customer design- CFD-Solver-Benchmark - Steady state (MFR) and transient flow- Coarse mesh (approx. 1 Mio. nodes)- Experimental data available



Example 3. Radial BlowerComments- Customer design- CFD-Solver-Benchmark - Steady state (MFR) and transient flow- Coarse mesh (approx. 1 Mio. nodes)- Experimental data available



Example 3. Radial Blower




0

500

1000

1500

2000

2500

3000

3500

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20

Stat

icP

ress

ure

Dif

fere

nce

[Pa]

Q [m^3/s]

dp_InOut CCM+

dp_InOut CCM+ (transient)

dp_InOut Solver I

dp_InOut Solver II

dp_InOut Messung



0

500

1000

1500

2000

2500

3000

3500

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

Stat

icP

ress

ure

Dif

fere

nce

[Pa]

Q [m^3/s]

dp_InOut Solver Mean

dp_InOut Solver Max

dp_InOut Solver Min

dp_InOut Messung





0

100

200

300

400

500

600

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20

Pow

er P

I [W

]

Q [m^3/s]

PI CCM+

PI CCM+ (transient)

PI Solver I

PI Solver II

P Messung




0

100

200

300

400

500

600

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

Pow

er P

I [W

]

Q [m^3/s]

PI Mean Solver

PI Max Solver

PI Min Solver

P Messung




0.0000

0.1000

0.2000

0.3000

0.4000

0.5000

0.6000

0.7000

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20

Effi

cien

cy [

-]

Q [m^3/s]

eta_InOut CCM+

eta_InOut CCM+ (transient)

eta_InOut Solver I

eta_InOut Solver II

eta_InOut Messung




0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

Effi

cien

cy [

-]

Q [m^3/s]

eta_InOut Solver Mean

eta_InOut Solver Max

eta_InOut Solver Min

eta_InOut Messung

Reasons of discrepancy between simulation and measurement should be investigated - mesh, time step, turbulence models,…

- check experimental set-up



Example 4. Virtual Automotive Cooling Fan Test Rig

Downstream channelwith or w/o blockage

HeatExchanger

Impeller

Stator

- Customers supplier design- CFturbo impeller re-design - Performance curve simulations, Steady state

(MFR) + transient flow on a virtual testbench- Scientific investigation on downstream flow

patterns and performance curves- A challenge: PACKAGING




Mixing Plane (Stage Inteface)

Mean values of pressure and momentumare used to provide radial distribution

Frozen Rotor

1:1 direct transfer of all physical valuesto the other side of the interface

Are these steady state models a good alternatives compared to transient simulation of axial automotive cooling fans?



Frozen Rotor TransientMixing Plane

Downstream flow patterns




Stat

icP

ress

ure

Dif

fere

nce

[Pa]

Transient

Mixing Plane (MP)

Frozen Rotor (FR)

Steady state CFD-solutions aredependent on the position ofthe Rotor-Stator-Interfaces!

>> Computation of energytransmission within theimpeller is affected!

Volume flow Q/Qref

Performance Curves




Frozen Rotor

Transient

Mixing Plane




Summary

CFturbo® and STAR CCM+ is a powerful combination for conceptual Turbomachinerydesign and 3D-CFD-simulation

For different Turbomachinery applications different methodologies may be necessary

Transient simulations do provide more accurate results im most cases

Automated workflows and multi-objective optimization processes are available byadditional application of OPTIMATETM and HEEDSTM

Various types of Turbomachinery can be designed and investigated effectively• pumps, blowers, compressors, turbines• radial, mixed-flow and axial type• incompressible and compressible flow• without and with cavitation

Documents

Several Examples of Turbomachinery Design and … Examples of Turbomachinery Design and CFD-Simulation ... CATIA, Creo, UG NX, SolidWorks, SpaceClaim, … Production Computation, optimization: