Sub – Project 2 Intercooled Recuperative · PDF fileSub – Project 2 Intercooled...

European Engine Technology Workshop

2-3 June 2009

Sub – Project 2Sub – Project 2Intercooled Recuperative Core

Stefan Donnerhack, MTU

NEWAC is an Integrated Project Co-funded by the European Commission within the Sixth Framework Programme(2002-2006) under Thematic Priority 4 Aeronautics and Space.

European Engine Technology Workshop Warsaw, 2-3 June 2009


2-3 June 2009

� IRA cycle, investigated in EEFAE CLEAN, will use sig-nificant benefits from further increased propulsive and

SP2 Intercooled Recuperative Core – Introduction

nificant benefits from further increased propulsive and thermal efficiencies with a potential of up to 20% fuel consumption- and CO2-emission reduction

� The significant low OPR of IRA cycle supports by itself ultra low NOx combustor conditions and, hence, technologies, not applicable for high OPR engines, e.g. LPP combustion

� For targets beyond 2020, SP2 will initiate studies on even more innovative core concepts relative to IRA on system level and develop a roadmap to even higher targets then

IRA concept


level and develop a roadmap to even higher targets then ACARE 2020.

The high level objective for SP2 is:

� Further develop IRA core components resulting in 2% SFC reduction in addition to 16% SFC reduction achieved from CLEAN IRA and 1% propulsion system weight reduction

2

PD pulse detonation concept


2-3 June 2009

SP2 Intercooled Recuperative Core – Technical Approa ch

Links to other SP’s:

�SP3, SP4, SP5

Recuperator geometry and arrangement

� Minimise pressure drop while keeping heat exchanger matrix constant

Compressor optimisation with respect to efficiency & surge margin and with respect to a satisfying fit to ducting for the radial arrangement

�SP3, SP4, SP5

�SP6

�SP3, SP4


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heat exchanger matrix constant

�modified heat exchanger and nozzle geometry arrangement

�adapted flow guidance

�improved heat exchanger dimensions

� Design and integration

the radial arrangement

� Hub to tip radius ratio at the inlet

� Polytropic efficiency and weight of radial compressor stage

� Radial / axial diffuser to optimise ducting


2-3 June 2009

SP2 Intercooled Recuperative Core: Road Map H

EX

arrangement &

TRL

2IRA system study for pylon & power plant integrationIRA

performance

radial HP

CH

EX

arrangement &

nozzle geometry

Comparative study on ax-/rad compressor

Analytical study on heat exchange & losses by using

CFDExperimental setup and

validation on heat exchange and losses

2

2

3

2

Review status of

IRA performance

Heat exchanger arrangement and nozzle

geometry concept

Heat exchange& loss modelling

IRA system study for pylon & power plant integrationperformance

Interface & integration study


M1 M30 M48

radial HP

C

Design of “SOA“rad-compressor

Advanced rad-compressor design &compressor with axial diffusor

Rig Test 5

concept design test


2-3 June 2009

SP2 Intercooled Recuperative Core – Benefits and imp act

2.12.12.12.1 2.22.22.22.2 2.32.32.32.3SP2

Specification , Assessment & Coordination


2.1



2.1

IRA components(TRL=5 for HPC;TRL=3 for other

NEWAC modules)


NEWAC modules)

2.2


NEWAC modules)


NEWAC modules)

2.2

Future Innovative Core

Configurations(TRL = 2)



2.3





2.3

Improved radial HPC performance

Improved radial HPC performance

Optimised & Improved IRA configuration

Optimised & Improved IRA configuration

HPC: +0,8% efficiencyHPC: +0,8% efficiency HPC: -10% weightHPC: -10% weightRecuperator pressure

Loss -15% Recuperator pressure

Loss -15% (Max Climb)

Constant weightConstant weight

SP2Intercooled

Recuperative Core

Exploitable Outcomes

ComponentSignificance

Optimised (variable) core geometryNovel combustion concept

Optimised heat management

Optimised (variable) core geometryNovel combustion concept

Optimised heat management


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HPC: +0,8% efficiency HPC: -10% weight Loss -15% (Max Climb)(Max Climb)

Constant weight

- 2% SFC- 2% SFC -1% weight-1% weight -0% Weight-0% WeightEngine

Significance-5% SFC

versus IRA baseline-5% SFC

versus IRA baseline


2-3 June 2009

SP2Intercooled recuperative core

S. Donnerhack, MTU

SP2 Intercooled Recuperative Core – Organisation

WP2.1 Coordination

& specificationS. Donnerhack, MTU

WP2.2IRA components

S. Donnerhack, MTU

WP2.3Future innovative

core configuration A. Lundbladh, VAC

SpecificationIRA engine

concepts studies

Lead

MTU

TM

VAC

Chalmers

TUG

Recuperatorloss analysis

Coordination

Variable corecycle

Assessment & coordination


Dissemination& training

PCA

PartnersAI-FDLRAUTHPBS

Optimisation of heatexchanger- and flow-

arrangement

Comparison axial/radial HPC and opt. of HPC

outlet/ducting interfaces

Radial compressor

Innovativecombustion

Contra-rotatingcore

Unconventionalheat management


2-3 June 2009

SP2 Intercooled Recuperative Core – Research perform ed (1/6)

Recuperator loss analysis: development of heat exch anger porosity model

Necessity of a porosity model:

HEX cross-section is charac-terized by a large number of lancets with elliptic cross-section.

for CFD investigation, the computational domain usually is discretized in form of a mesh.

MTU Lancet HEX for IRA


7

for CFD investigation, the computational domain usually is discretized in form of a mesh.for the flow through a HEX a complete discretization may be impossible due to:

� large number of lancets ➨ huge meshing time / effort➨ large mesh size and complexity

� strong variations of lancets distances ➨ reduces the mesh quality➨ convergence problems expected

➨ proposed solution: porosity model


2-3 June 2009


Heat exchanger to be Principle of the Porosity model

Recuperator loss analysis: development of heat exch anger porosity model

Heat exchanger to be modeled as porous medium

4-3-4 element HEX matrix configuration in the heat exchanger

x

yz

Principle of the Porosity model➨ modeling of the HEX-induced pressure loss

by the use of user-defined source terms applied within a domain defined as ‘porous’

➨ The Darcy-Forchheimer formulation for the pressure loss through a porous media was chosen in order to describe the pressureloss across the HEX-matrix:

ii UUUP βρµ +=∂−


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the heat exchanger

µ: Dynamic viscosityκ: Permeabilityβ: Forchheimer Factor (loss coefficient)

➨ Permeability and loss coefficients have been defined for x,y and z, resp. r, θ and z directions, in the form of 3x3 matrices

iii

UUUx

βρκ

+=∂

−

y

xr,θθθθ


2-3 June 2009


Optimisation of HEX- and flow-arrangement: main modi fications of the quarter nozzle

optimized HEX configuration:optimized HEX configuration:� 17º-20º-13º-17º HEX inclination in quarter nozzle

(initial inclination 0º-20º-20º-0º in CLEAN)� ideal mass-flow distribution within a range of

-1.0% … +1.3% from 25% base(initial range: -3.3% … +4.1% from 25% base in CLEAN)


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aerodynamic ramp behind Matrix 3 (in grey)optimization of aerodynamic cone contour (in red)

more homogeneous distribution in total pressure & velocity upstream of matrices

➨ optimized nozzle with significant lower pressure lo ss than reference nozzle


2-3 June 2009


Comparison of axial and radial HPC options for IRA

Characteristics of radial HPC mechanical design:Characteristics of radial HPC mechanical design:• minimise impeller mass at acceptable peak stress, burst

margin and 1st. mode frequency• material selection: titaniumadvantage: short length, low number of vanesdisadvantage: high impeller mass & inertia, low efficiency➨ further iterations needed to achieve a feasible design

Characteristics of axial HPC mechanical design:

impeller stress distribution from FE


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• minimise rotor mass at acceptable peak stress, burst margin and 1st. mode frequency

• material selection: titaniumadvantage: high HPC efficiency, low mass & inertiadisadvantage: longest configuration, high blade count➨ current results indicate a feasible mechanical design➨ optimisation potential due to margins in stress-level rotor deformations from FE

(deformation scaling factor: ~60)


2-3 June 2009


Design study on 3D leading edge of a small scale ra dial diffuser

� first promising results from comprehensive set of testing 3D leading edge radial diffuser� first promising results from comprehensive set of testing

� preparation of the 3D LE radial diffuser in order to identify its surge behavior and overall performance map

� making use of PBS small jet engine test facility

3D leading edge radial diffuser


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PBS small jet engine test facility

basic data of PBS small jet engine

max. thrust: 110dN

electrical power output: 750W

max. diameter: 0.272m

length: 0.625m

weight (dry): 20.6kg


2-3 June 2009


Future innovative core configuration: Study on cont ra rotating core (CRC)

Various system considerations on an innovative CRC -concept, e.g. onVarious system considerations on an innovative CRC -concept, e.g. on• Selection of suitable design elements

• Optimization of work distribution for thetwo rotors for minimized mechanical loads

• Integration of HPC bleed system into CRC

• Integration of SAS into CRC

• Considerations on module mounting &assembly requirements of CRC

• Integration of mechanical break-system foraero-dynamic controlled start procedure ➨ Development of an integrated 2D G/A


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aero-dynamic controlled start procedure

CRC initial benefit assessment:• ~20% core weight reduction

• up to ~35% core weight reduction by using BLISK technology

⇒Engine weight saving ~10% ⇒Fuel burn reduction for long-range A/C mission ~1.2%

➨ Development of an integrated 2D G/A


2-3 June 2009

SP2 Intercooled Recuperative Core – Conclusion

IRA is promising concept to reach the ACARE2020 targets

IRA concept

NEWAC SP2 is important step forward to further establish and improve the IRA

Focus of the SP2 is on IRA components:

- optimisation of HEX-arrangement and nozzle geometry

- improvements from advanced radial HPC

- IRA integration aspects

Current results (at year 3 of NEWAC) are indicating, the high level SP2 objectives:


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high level SP2 objectives:

- 2% SFC reduction in addition to 16% SFC reduction achieved from CLEAN IRA

- 1% propulsion system weight reduction

are achievable with sufficient level of confidence

MTU Lancet HEX for IRA

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