Presentation Acme engineering- Two Stage Turbo Shaft Engine- Pratt and Whittney

Gas Turbine DesignProject Presentation

ACME Aerospace Inc.

“History will be kind to me, for I intend to write it.”- Winston Churchill

Project Plan- Milestones

Overall Cycle Analysis for gas turbine configuration.

High Pressure Turbine.

Mean line Analysis Loss Calculations Smith’s Chart- The Sanity Check ! Rotor Geometry – Hub/ Tip Analysis

Design Selection - Engineering Analysis

Economic feasibility study – Tradeoffs !

OFF- Design Analysis

Business Case !

Aero + Stress

Costing…

ACME Aerospace Inc - Bringing Technologies of Change

Cycle Analysis

1

4

5

6

7

s

T

32

∆ 𝑷𝒃

(8 % + 1 %) Bleed + ACC(3.3 % + 1.65 %) Vane + Disk(2.1%) Disk

Cooling Details

Mass Flow Rates = 46.94 = 41.73 = 5.216 = 0.4698 = 0.095

FAN

BOO

ST STAG

E

HPC H

PT LPT

C/C

1 2 3 6 7

4 5 8


FAN

BOO

ST STAG

E

HPC H

PT LPT

C/C

1 2 3 6 7

4 5 8

Cycle Analysis

Mass Flow Rates = 46.94 = 41.73 = 5.216 = 0.4698 = 0.095

(8 % + 1 %) Bleed + ACC(3.3 % + 1.65 %) Vane + Disk(2.1%) Disk

Cooling Details

Stage

Component Pressure (bar)

Temperature(K)

0-1 Diffuser 0.268 244.431-2 Fan 0.3819 2732-3 Boost Comp. 1.072 382.513-4 HPC 3.216 549.424-5 C/C 3.158 1148.045-6 HPT 1.610 9716-7 LPT 0.241 645.27-8 Hot Nozzle 0.175 593.212-8 Cold Nozzle 0.165 207.2


High Pressure Turbine- Mean Line Analysis Parameter

sState 1 State 2 State 3

Temp (K) 1149.347 1038.2178 939.6054

P (bar) 3.15603268 2.359808269 1.434861637

C (m/s) 82.7328 446.5382 269.7755

Cw (m/s) 17.0223 485.6564 58.2745

Ca (m/s) 81.4523 180.1132 265.2863

Area (m2) 0.0606 0.0364 0.0364

Vw(m/s) - 150.3764 393.5545

β (°) - 39.8559 56.0173

V (m/s) - 234.6355 474.6177

MR - 0.3779 0.7928

TOR (k) - 1031.5134 1037.1271

POR (bar) - 2.22138546 2.09704923

M 0.1257 0.7093 0.45

α (°) -10 66.2609 10.5

R (%) 0.48

Y 0.0596 0.0446

ζ 0.1142 0.0761

η% 92.5%

Design Presumptions

Mach No

Swirl Angle

Inlet 0.125 -10

Exit 0.45 10.5

Vane BladeAspect Ratio 0.7 1.45

Zwiefel Coeff 0.8 0.95TE Thickness

(inches)0.045 0.025

Reaction- 0.48Efficiency – 0.87 = 4.5 x Work- 182.369 KJ/kg= 4.84174 = 5.015 = 5.1298

1

2

3

Inlet to nozzle vanesInlet to rotor

Exit of rotor

1

23


Loss Calculations/ Smith Chart

92.5

Smith ChartLosses Calculation

Nozzle Section Aerodynamic Loss Distribution

Kp Ks KteBlade Section Aerodynamic Loss

Distribution

Kp Ks Kte

58

65

2411

2715

Note: Tip Leakage losses are assumed 1 %.

- Trailing Edge

- Secondary

- Profile

Efficiency After Losses- 88.59 %


Stage Geometry- Hub Tip Analysis

-0.98

Metal Angles

-3

-4.3

64.04

67.26

70.65

48

50

57

Stagger AnglesVariation: 9

HUB

TIP

HUB

TIP

Vane Geometry- Hub Mean Tip

SI Units Hub Mean Tip

Stagger ɣ(°) 57 50 48

Height h 0.0540

Chord C 0.0772

0.0143 0.0137 0.0132

Axial chord 0.0420 0.0496 0.0516

N 18 18 18

Pitch (S) 0.0400 0.0471 0 .0589

Zwiefel (Ψ) - 0.8 -

Throat Ov 0.01347 0.0228 0.0258

°


Rotor Geometry- Hub Tip AnalysisBlade Geometry- Hub Mean Tip

-4.3

-19.44

8.7

39

63.16

60.29

57.07

Metal Angles

Stagger AnglesVariation: 32.5

52.5

38.0

20.0

HUB

TIP

TIP

HUB

SI Units Hub Mean Tip

Stagger ɣ(°) 20 38 52.5

Height h 0.0427

Chord C 0.0294

0.00575 0.0055 0.0048

Axial chord 0.0276 0.0232 0.0179

N 35 35 35

Pitch (S) 0.0206 0.0244 0 .0282

Zwiefel (Ψ) - 0.95 -

Throat Ov 0.0104 0.0121 0.0127

°


Assembled Rotor GeometryParameters Qty/ Measurements

No of Vanes 18No of Blades 35Pitch- 0.0244Axial 0.0232Throat 0.0121Blade height 0.0427Vane height 0.0540Mean radius ( Vane) 0.1418Mean radius (Blade) 0.1361

4.5 x

Blade

Vane

Design Nozzle Vanes

Rotor Blades

Design 1 (88.59%)

18 35

Design 2 (87.99%)

28 53

Design 3 (88.36%)

21 41

Design 4 (88.04%)

28 58

Design 5 (88.55%)

21 38

Lowest number of vanes and blade

Blade geometry details calculated for Design 1 ( η = 88.59 %)

View- A

View- B


Aerodynamic vs Stress Analysis

Aerodynamic Analysis

High AN^2 leads to greater value of “blade speed” which results in higher pitch and less number of blades

Lesser number of blades reduce Profile , TE and tip leakage losses. On contrary Secondary losses increase.

Efficiency increases.

30 35 40 45 50 55 6087.687.787.887.9

8888.188.288.388.488.588.688.7

Number of Blades vs Efficiency %

Number of Blades

Efficie

ncy

2.00E+10 3.00E+10 4.00E+10 5.00E+1087.687.787.887.9

8888.188.288.388.488.588.688.7

AN^2 vs Efficiency %

AN ^2

Efficie

ncy

20000000000 30000000000 40000000000 500000000000

10

20

30

40

50

60

70AN ^2 vs # of Blades

AN ^2

No o

f Bla

des

Decrease in # of blades with increasing

D= 4.5 x

Increase in efficiency with

Decrease in efficiency with increasing # of blades


Stress Analysis

High AN^2 leads to greater value of “blade speed” which results in higher “Centrifugal Tensile Stress”

More stretched blade , results in lesser effect of “Gas Bending Stress”.

High efficiency corresponds to low gas bending but high centrifugal stresses.

Aerodynamic vs Stress Analysis

2.00E+102.50E+103.00E+103.50E+104.00E+104.50E+105.00E+100

0.2

0.4

0.6

0.8

1

1.2

1.4Gas Bending Stress vs AN^2

AN ^2

Gas B

endi

ng S

tress

(MPa

)

Reduction in Gas bending stress with increasing 𝐴𝑁^2

2.00E+10 3.00E+10 4.00E+10 5.00E+10050

100150200250300350400450 Centrifugal Tensile Stress vs AN ^2

AN ^2

Cent

rifug

al S

tress

(MPa

) Linear relationship b/w Centrifugal stress & 𝐴𝑁^2

87.9 88 88.1 88.2 88.3 88.4 88.5 88.6 88.70

50100150200250300350400450

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Centrifugal / Gas Bending Stress vs

Efficiency

Centrifugal Tensile Stress (Mpa)Efficiency

Cent

rifug

al T

ensil

e (M

Pa)

Gas B

endi

ng (M

Pa)

Increasing Centrifugal stress

Decreasing Bending Stress


Cost Analysis

Design-1 (88.59%)

Design-2 (87.9918 %)

Design-3 (88.36 %)

Design-4 (88.045 %)

Design-5 (88.554 %)

050000

100000150000200000250000300000350000400000450000500000

Comparision of Engine Design for Total Relative Cost vs Efficiency

5000 Hrs 4000 Hrs 7000 HrsMaterial With Efficiency

Tota

l Rel

ativ

e Co

sts

$

Analysis

FORMULATotal Cost = Fuel Cost + Total Blade Cost + Overall Maint. Cost

Material Z is coming with lowest total cost with different number of blade configurations (or designs)

Analysis

FORMULATotal Relative Cost = Overall Maint. Cost + Total Blades Cost + Relative Fuel Cost

Considering Design 1 as our baseline Relative Fuel Cost = 0 $

For Design 1, Total Relative Cost for 7000 hrs. is minimum.

X = 5000 hrs.Y = 4000 hrs.Z = 7000 hrs.

X Y z X Y z X Y z X Y z X Y z35 38 41 53 58

107501080010850109001095011000110501110011150

Overall Cost v/s Blade Count

Number of blades with material

Tota

l Cos

t x 1

000

$


87.9 88 88.1 88.2 88.3 88.4 88.5 88.6 88.70

10

20

30

40

50

60

70

10840

10860

10880

10900

10920

10940

10960

10980Number of Blades/Total Cost vs Efficiency

Efficiency %

Num

ber o

f Bla

des

Tota

l Cos

t x 1

000

$

Eff % vs Total Cost

Eff % vs Number of Blades

88.59 % (35)

88.55 % (38)

88.36 % (41)

88.04 % (58)

87.99 % (53)

106.6106.7106.8106.9

107107.1107.2107.3107.4107.5107.6107.7

533

534

535

536

537

538

539

Efficiency v/s Fuel Consumption/ Fuel Cost

Efficiency (Number of blades)

Fuel

Con

sum

ptio

n (G

allo

ns/H

r)

Fuel

Con

sum

ptio

n co

st ($

/Hr)

Analysis With decreasing efficiency fuel consumption and

cost increases. Lesser efficiency corresponds to more number of

blades hence more losses and greater quantity of fuel is required to fly an aircraft.

Reduction in Power to Weight Ratio with more # of blades

Cost Analysis


Design Selection – Aero + Stress +Cost

87.9 88 88.1 88.2 88.3 88.4 88.5 88.6 88.710840

10860

10880

10900

10920

10940

10960

10980

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Aerodynamics/Stress Analysis vs Cost (Material Z )

Total Cost (Z-Material) x 1000 Gas Bending Stress (Mpa)Efficiency %

Tota

l Cos

t x 1

000

($)

Gas B

endi

ng S

tress

(MPa

)

𝑨𝑵^𝟐=4.5 x 𝟏𝟎^𝟏𝟎

30 35 40 45 50 55 6087.687.787.887.9

8888.188.288.388.488.588.688.7

0.00

10000.00

20000.00

30000.00

40000.00

50000.00

60000.00

70000.00

Fuel Cost Difference/ Number of Bladesvs

Efficiency

Number of Blades

Efficie

ncy

%

Fuel

Cos

t Diff

eren

ce/ A

nnum

# %𝐵𝑙𝑎𝑑𝑒𝑠 𝑣𝑠 𝐸𝑓𝑓# 𝐵𝑙𝑎𝑑𝑒𝑠 𝑣𝑠 𝐹𝑢𝑒𝑙

𝐶𝑜𝑠𝑡 𝐷𝑖𝑓𝑓

𝑨𝑵^ = 4.5 x ^𝟐 𝟏𝟎 𝟏𝟎(Design 1)

Analysis

With increasing efficiency, total cost as well as gas bending stress has minimum value.

For 4.5 x Efficiency = 88.59 % Design 1

Analysis

Increasing number of blades lead to reduced efficiency and more Aerodynamic losses.

Further relative fuel cost increases with more number of blades pointing to the fact that greater quantity of fuel will be required to travel longer distances.

Chosen DesignCost of Engine – 10.88 M ($) ACME Aerospace Inc - Bringing Technologies of

Change

OFF- Design Analysis

800 900 1000 1100 1200 1300 1400 1500 1600 1700200.00

250.00

300.00

350.00

400.00

450.00

500.00

550.00

600.00

0

10

20

30

40

50

60

70

80

90

100

Performance Analysis of Peak Cycle Temperature

Peak cycle temperature (K)

Fuel

Con

sum

ptio

n (K

g/Hr

)

Efficie

ncy

(%)

Design (88.59 %)

Increasing Fuel Consumption

Efficiency

88 88.5 89 89.5 90 90.50

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Tip Control Clearance vs Efficiency

Efficiency (%)

Tip

Cont

rol C

lear

ance

(%)

Analysis

With increasing peak cycle temperature, fuel consumption increases since more fuel needs to be burned.

A sharp increase in efficiency to a maximum value and then it dips and remains constant.

With increasing ACC supply, tip clearance reduces and hence reduction in tip leakage losses

Decrease in efficiency with an increase in tip clearance


Other Design Options : For lower than chosen value –

Design 2 • # of Blades = 38 More Weight • Increase in Cost = $ 6627 • Decrease in Centrifugal Tensile Stress =

44.73 MPa.

Design 3 • # of Blades = 41 More Weight • Increase in Cost = $ 30256 • Decrease in Centrifugal Tensile Stress =

89.46 MPa.

Efficiency Front Decrease in efficiency can be countered by

increasing peak cycle temperature slightly which will not affect our blade metallurgy as well.

Parameter Design-1 Design-2 Design-3Efficiency 88.59 88.55 88.36

AN^2 4.5*10^10 4*10^10 3.5*10^10No Of Blades 35 38 41

Centrifugal Tensile Stress (MPa) 402.573 357.84 313.11

Gas Bending Stress (MPa)

0.71212106 0.806799171 0.98

Total Cost ($) 10888097.35 10894725.07 10918354.12

Difference in Cost ($) - 6627.72 30256.76Difference in

Centrifugal Stress (MPa)

- 44.73 89.46

Chosen Design

900 1000 1100 1200 1300 1400 1500 1600 17000

102030405060708090

100

0

0.04

0.08

0.12Peak Cycle Temp vs SFC & Eff. %

Peak Cycle Temperature - K

Efficie

ncy

%

SFC

(kg/

hr.N

)

Efficiency %

SFC

Design 2/3

Slight increase in T


Business Case…

Why ACME Aerospace … Team Synergy Customer consciousness Two pronged expertise

Aerodynamics + Stress

Inevitable Choice !

High efficiency Lesser Cost High “Power to Weight” Ratio

Less fuel consumption Better Specific Aircraft Range (SAR) miles/lbm of fuelLess fuel requirement More space for passengers …

Low Maintenance Downtime More Operational Time …

MORE REVENUES !

More options in design available


MERCI… !ACME Aerospace Inc

Bringing Technologies of Change

Presentation Acme engineering- Two Stage Turbo Shaft Engine- Pratt and Whittney

Engineering

Transcript of Presentation Acme engineering- Two Stage Turbo Shaft Engine- Pratt and Whittney