The objective was to develop and verify a series of interdisciplinary modeling and analysis techniques specialized to address hot section components. These techniques incorporate data as well as theoretical methods from many diverse areas, including cycle and performance analysis, heat transfer analysis, linear and nonlinear stress analysis, and mission analysis

Mcknight, R. L.

Tipton, M. T.

English

NASA Technical Reports Server

COMPONENT SPECIFIC MODELING 
R . L .  McKnight  and M . T .  T i p t o n  
Genera l  E l e c t r i c  A i r c r a f t  Eng ines  
C i n c i n n a t i ,  O h i o  
The o v e r a l l  o b j e c t i v e  o f  t h i s  program was t o  develop and v e r i f y  a s e r i e s  
o f  i n t e r d i  s c i  p l  i n a r y  model i ng and a n a l y s i  s techniques s p e c i a l  i z e d  t o  address 
h o t  s e c t i o n  components. These techniques i n c o r p o r a t e  d a t a  as w e l l  as 
t h e o r e t i c a l  methods f rom many d i v e r s e  areas i n c l u d i n g  c y c l e  and performance 
a n a l y s i s ,  hea t  t r a n s f e r  a n a l y s i s ,  l i n e a r  and n o n l i n e a r  s t r e s s  a n a l y s i s ,  and 
m i  s s i o n  a n a l y s i  s .  
these f i e l d s ,  t h e  new methods developed th rough t h i s  c o n t r a c t  were 
i n t e g r a t e d  i n t o  a system which p rov ides  an accura te ,  e f f i c i e n t ,  and u n i f i e d  
approach t o  a n a l y z i n g  h o t  s e c t i o n  s t r u c t u r e s .  
t h i s  c o n t r a c t  p r e d i c t  temperatures,  de format ion ,  s t r e s s  and s t r a i n  h i s t o r i e s  
th roughout  a complete f l i g h t  miss ion .  
Bui 1 d i n g  on t h e  proven techniques a1 ready  ava i  1 ab1 e i n 
The methods developed under 
The Component S p e c i f i c  Model ing program i s  shown i n  F i g u r e  1. Nine 
separa te  tasks  were per formed i n  two para1 1 e l  a c t i v i  t i e s .  The component 
s p e c i f i c  thermomechanical l o a d  m iss ion  model ing a c t i v i t i e s  a r e  shown i n  
F i g u r e  2. The p roduc ts  o f  these a c t i v i t i e s  were t h e  develooment o f  computer 
s i m u l a t i o n  models f o r  t h e  engine m iss ion  c y c l e ,  t h e  engine thermodynamic 
performance, and t h e  component thermal  p r e d i c t i o n .  The Component S p e c i f i c  
S t r u c t u r a l  Mode l ing  a c t i v i t i e s  a r e  shown i n  F igu re  3. 
a c t i v i t i e s  were t h e  development o f  a computer system c o n t r o l l e d  th rough an 
execu t ing  module which d i r e c t s  t h e  work o f  t h e  component s p e c i f i c  
thermomechanical l o a d  m iss ion  model ing so f tware ,  t h e  component geometr ic  
model i ng so f tware ,  and t h e  component s t r u c t u r a l  a n a l y s i  s so f tware  t o  pe r fo rm 
a component s p e c i f i c  nonl  i n e a r  a n a l y s i  s .  
The p roduc t  o f  these 
The r e s u l t s  o f  t h i s  program have exceeded o r i g i n a l  expec ta t i ons .  
p r o d u c t i v i t y  enhancer, t h i s  s y s t e m  has demonstrated t h e  a b i l i t y  t o  compress 
t h e  t i m e  span o f  a h o t  s e c t i o n  component m iss ion  a n a l y s i s  f rom months t o  
l e s s  than a day. A long w i t h  t h i s  t i m e  compression comes inc reased  accuracy 
f rom t h e  advanced model ing and a n a l y s i s  techniques.  A s  a r e s u l t  o f  t h i s ,  
more a n a l y t i c a l  des ign  s t u d i e s  can be performed, reduc ing  t h e  chances f o r  
f i e l d  s u r p r i s e s  and t h e  amount o f  component t e s t i n g  r e q u i r e d .  
A s  a 
https://ntrs.nasa.gov/search.jsp?R=19890007949 2020-03-20T03:18:19+00:00Z
THERMODYNAMIC AND THERMOMECHANICAL MODELS 
The Ihermodynamic Engine Model (TDEM) i s  t h e  subsystem o f  computer 
so f tware  which t r a n s l a t e s  a l i s t  o f  m iss ion  f l i g h t  p o i n t s  and d e l t a  t imes 
i n t o  t i m e  p r o f i l e s  o f  major  engine performance parameters. 
base con ta ins  CF6-5OC2 engine performance da ta .  
system t o  a d i f f e r e n t  engine r e q u i r e s  o n l y  t h e  r e s t o c k i n g  o f  t h i s  da ta  base 
w i t h  t h e  a p p r o p r i a t e  engine performance da ta .  
I t s  p resen t  da ta  
I n  o r d e r  t o  adapt t h i s  
The Ihermodynamic Loads Model (TDLM) i s  t h e  subsystem o f  computer 
sof tware which works w i t h  t h e  o u t p u t  o f  t h e  TDEM t o  produce t h e  m iss ion  
c y c l e  l o a d i n g  on t h e  i n d i v i d u a l  h o t  s e c t i o n  components. There a r e  separa te  
segments f o r  t h e  combustor, t h e  t u r b i n e  b lade,  and t h e  t u r b i n e  vane. These 
segments t r a n s l a t e  t h e  major  engine performance parameter p r o f i l e s  f rom t h e  
TDEM i n t o  p r o f i l e s  o f  t h e  l o c a l  thermodynamic loads (pressures,  
temperatures,  RPM) f o r  each component. The formulas which pe r fo rm t h i s  
mapping i n  t h e  TDLM models w e r e  developed f o r  t h e  s p e c i f i c  engine 
components. 
eva l  u a t i  ng these fo rmul  as f o r  t h e i  r s i  mu1 a t i  on capabi 1 i ty  and maki ng any 
necessary changes. 
To adapt  these models t o  a d i f f e r e n t  engine would r e q u i r e  
COMPONENT S P E C I F I C  STRUCTURAL MODELING 
The h e a r t  o f  t h e  Component S p e c i f i c  S t r u c t u r a l  Model ing i s  geometr ic  
mode l ing  and mesh genera t i on  u s i n g  t h e  r e c i p e  concept. 
i t s  wor th  as a p r o d u c t i v i t y  enhancer. A gener i c  geometry p a t t e r n  i s  
determined f o r  each component. A r e c i p e  i s  developed f o r  t h i s  b a s i c  
geometry i n  terms o f  p o i n t  coord ina tes ,  l eng ths ,  th icknesses ,  angles,  and 
r a d i i .  
i n p u t  parameters.  A s e t  o f  d e f a u l t  numer ica l  va lues  a re  s t o r e d  f o r  these 
parameters. 
t o  have d i f f e r e n t  va lues .  These r e c i p e  parameters then u n i q u e l y  d e f i n e  a 
gener i c  component w i t h  t h e  d e f i n e d  dimensions. 
works w i t h  these parameters t o  develop a f i n i t e  element model o f  t h i s  
geometry cons i  s t i n g  o f  20-noded i soparametr i  c elements. The u s e r  spec i  f i  e s  
t h e  number and d i s t r i b u t i o n  o f  these elements th rough i n p u t  c o n t r o l  
parameters.  F i g u r e  4 shows t h e  gener i c  geometry and r e c i p e  f o r  a combustor 
1 i ner  panel . 
Th is  i d e a  has proved 
These r e c i p e  parameters a re  encoded i n  computer so f tware  as v a r i a b l e  
The use r  need o n l y  i n p u t  va lues  f o r  those parameters which a re  
The so f tware  l o g i c  then 
The subsystem which per forms t h e  three-d imensional  n o n l i n e a r  f i n i t e  
element a n a l y s i s  o f  t h e  h o t  s e c t i o n  component model was t h a t  developed i n  
t h e  NASA HOST program, "3D I n e l a s t i c  Ana lys i s  Methods f o r  Hot S e c t i o n  
S t r u c t u r e s .  'I Thi s so f tware  per forms i ncremental nonl  i near f i  n i  t e  e l  ement 
260 
a n a l y s i s  o f  complex 3D s t r u c t u r e s  under c y c l i c  thermomechanical l o a d i n g  w i t h  
temperature dependent m a t e r i a l  p r o p e r t i e s  and m a t e r i a l  response behav io r .  
The n o n l i n e a r  a n a l y s i s  cons iders  bo th  t i m e  independent and t i m e  dependent 
m a t e r i a l  behav io r .  Among t h e  c o n s t i t u t i v e  models a v a i l a b l e  i s  t h e  
H a i s l e r - A l l e n  c l a s s i c a l  model which performs p l a s t i c i t y  a n a l y s i s  w i t h  
i s o t r o p i c  m a t e r i a l  response, k inemat i c  m a t e r i a l  response, o r  a combinat ion 
o f  i s o t r o p i c  and k i n e m a t i c  m a t e r i a l  response. This  i s  combined w i t h  a 
c l a s s i c a l  creep a n a l y s i s  f o r m u l a t i o n .  
pe r fo rm time-dependent analyses i s  a dynamic t i m e  i nc remen t ing  s t r a t e g y  
i n c o r p o r a t e d  i n  t h i s  so f tware .  
A major advance i n  t h e  a b i l i t y  t o  
COSMO SYSTEM 
The COSMO s y s t e m  c o n s i s t s  o f  an execu t i ve  module which c o n t r o l s  the  
TDEM, TDLM, t h e  geometr ic modeler, t h e  s t r u c t u r a l  a n a l y s i s  code, t h e  f i l e  
s t r u c t u r e / d a t a  base, and c e r t a i n  anc i  1 l a r y  modules. 
c o n s i s t  o f  a bandwidth o p t i m i z e r  module, a deck genera t i on  module, a 
remeshing/mesh re f i nemen t  module and a pos tprocess ing  module. 
d i r e c t s  t h e  r u n n i n g  o f  each module, c o n t r o l s  the  f l o w  o f  d a t a  among modules 
and c o n t a i n s  t h e  s e l f - a d a p t i v e  c o n t r o l  l o g i c .  F igu re  5 i s  a f l o w  c h a r t  o f  
t h e  COSMO s y s t e m  showing t h e  da ta  f l o w  and t h e  a c t i o n  p o s i t i o n s  o f  t he  
adap t i ve  c o n t r o l s .  The modular design of  t h e  s y s t e m  a l l o w s  each subsystem 
t o  be viewed as a p l u g - i n  module. They can be a b s t r a c t e d  and r u n  a lone o r  
rep1 aces w i  t h  a1 t e r n a t e  sys tems.  
These anc i  1 l a r y  modules 
The execu t i ve  
CONCLUSIONS 
The ideas ,  techn iques ,  and computer so f tware  developed i n  t h e  Component 
S p e c i f i c  Model ing Program have proven t o  be e x t r e m e l y  v a l u a b l e  i n  advancing 
t h e  p r o d u c t i v i t y  and des ign-ana lys is  c a p a b i l i t y  f o r  h o t  s e c t i o n  s t r u c t u r e s .  
Th is  so f tware  i n  c o n j u n c t i o n  w i t h  modern supercomputers i s  a b l e  t o  reduce a 
des ign  task which p r e v i o u s l y  r e q u i r e d  man-months o f  e f f o r t  ove r  a t i m e  
p e r i o d  o f  months t o  a one man, l e s s  than a day e f f o r t .  The ideas  a re  
amenable t o  f u r t h e r  g e n e r a l i z a t i o n / s p e c i a l  i z a t i o n  and ex tens ion  t o  a1 1 areas 
o f  t h e  engine s t r u c t u r e .  
t h e  n e x t  g e n e r a t i o n  o f  aerospace p r o p u l s i o n  s y s t e m s  w i t h  t h e i r  i n c r e a s i n g l y  
l a r g e r  number o f  pa ramet r i c  v a r i a t i o n s .  
These techniques w i l l  have t h e i r  ma jor  p a y o f f  i n  
26 1 
Task I - 
Survey 
t 
i w 
Component- 
Specific 
Structural 
Modeling 
Task I 1  
Task VI 
Task VI11 
So€ tware 
Development 
~~ 
Task IV 
Component- 
Specific 
Thermomechanical 
Load Mission 
Mode 1 i ng 
Task 111 
Task V 
Task V I 1  
-7-- 
Reporting 
Task IX 
F i g u r e  1, Component S p e c i f i c  Mode l ing  Base Program. 
I Task [ I1  I 
I ‘r h e r m o  d y n am i c I Engine Model 
Task V 
Nission Model 
Decomposition 
Task VI1 
Thermomechanical Load 
Mission Model 
Development 
-- 
De compos i t ion / S y n t h e s i 
Capability 
F i g u r e  2 .  Component S p e c i f i c  Thermomechanica l  Load 
M i s s i o n  Model ing .  
26 2 
Task I1 
Design Structural Analysis 
Software Architecture 
Task VI 
Structural Analysis 
Methods Evaluation 
L 
Task VI11 * Component Specific Modeling 
- - - - -  - -  - - 
Develop Geometric 
Modeling and Display 
Develop Structural 
Analysis Capability 
Figure 3. Component Specifi.c Structural Modeling. 
26 3 
m m  L.8 
a 0 m m m O w a O O ” m  a , , . . , . , . . . . 
w 0 0 0 0 N 0 0 0 ~ 0 ~  m u -  
c1 
X 
h 
0 
hl 
W 
m e: 
4  
a o o o o o m m m o o m m  
,q . . . . . . . . , . . . 
CI 
w u O o ~ a ~ 0 0 0 0 d - -  m 
--- t 
I 
264 
Main Executive c 
I TDEM 1 
I Component Recipe 
I 
I 
Bandwidth Optimizer +  Deck Generation 
I 
Structural Code + 
I Data Base Routines 1 
Remesh/Mesh Refine 1
Postprocessing L_7__1 
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
T I M E  INCREMENT 
LOAD INCREMENT 
P L A S T I C I T Y  TOLERANCES 
CREEP TOLERANCES 
NUMBER OF MASTER 
REGION ELEMENTS 
NUMBER OF S L I C E S  
P O S I T I O N  OF S L I C E S  
ROW REFINEMENT 
ELEMENT REFINEMENT 
Figure 5. System Flow Chart Showing 
Adaptive Control Positions. 
265 


Component specific modeling

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server