The antimisting additive ((FM-9) was tested in terms of its propulsion systems performance. The effect of the additive on engine operation was evaluated, operating problems were identified, the adaptability of engines to antimisting kerosene was assessed, and the potential viability of this fuel for use in present and future fan jet engines was determined

Schmidt, H. W.

English

NASA Technical Reports Server

ANTIMISTING KEROSENE 
Harold W. Schmidt 
National Aeronautics and Space Administration 
L e w i s  Research Center 
Antimis t i n g  kerosene (AMK) is a kerosene- f r a c t i o n  j e t  f u e l  containing an 
add i t ive  t h a t  reduces the  flammability of t h e  f u e l  i n  an a i r c r a f t  c rash  circum- 
s tance .  AMK add i t ives ,  when dissolved i n  Jet  A f u e l  i n  concentrations i n  t h e  
range of 0.3 percent ,havebeen  demonstrated t o  i n h i b i t  i g n i t i o n  and flame prop- 
agation of t h e  re leased  f u e l  i n  simulated crash tests. The AMK f u e l  resists 
misting and atomization from wind shear and impact forces and ins tead  tends t o  
agglomerate i n t o  globules. This agglomeration s i g n i f i c a n t l y  reduces i g n i t i -  
b i l i t y  and flame propagation. 
Several  AMK add i t ives  have been developed and evaluated f o r  t h e i r  poten- 
t i a l  t o  reduce post-crash f i r e s .  The ant imis t ing  add i t ive  (FM-9), se l ec t ed  f o r  
more comprehensive t e s t i n g  i n  t h i s  program, was developed by t h e  Imperial  Chem- 
i c a l  Indus t r i e s  and the  Royal A i r c r a f t  Establishment of t h e  United Kingdom and 
i s  being evaluated f o r  c r a s h - f i r e  r e s i s t ance  by t h e  U.S. FAA i n  an agreement 
with the  United Kingdom. 
The NASA has agreed t o  conduct propulsion system tests f o r  t he  FAA. The 
purposes of the  tests a r e  t o  eva lua te  the  e f f e c t s  of the  add i t ive  on engine op- 
e ra t ion ,  t o  i d e n t i f y  opera t ing  problems, t o  assess the  a d a p t a b i l i t y  of e x i s t i n g  
engines t o  AMK, and t o  determine the  p o t e n t i a l  v i a b i l i t y  of t h i s  f u e l  f o r  use 
i n  present  and fu tu re  f a n - j e t  engines. The P r a t t  & Whitney A i r c r a f t  Group has  
been contracted t o  perform the  experimental test  program on the  JT8-D engine 
and fue l  sys t e m  components. 
This add i t ive ,  FM-9, which c rea t e s  t he  high shear r e s i s t a n c e  des i r ab le  i n  
the  crash circumstance, r e s u l t s  i n  non-Newtonian flow c h a r a c t e r i s t i c s  t h a t  
cause some undesirable behavior i n  t h e  engine f u e l  system. 
u re  l ( a )  shows the  t y p i c a l  atomization of Jet  A f u e l  i n  a standard JT8-D nozzle 
a t  i g n i t i o n  flow ra t e s .  Figure l ( b )  shows the  behavior of undegraded AMK i n  
the same nozzle. However, i n  ac tua l  conditions,  the  AMK would be p a r t i a l l y  de- 
graded from being pumped through t h e  f u e l  cont ro l  system. S imi la r ly ,  f i gu re  2 
shows the  e f f e c t  of t he  nozzle design on undegraded AMK. Figure 2(a) is f o r  
the  standard nozzle, and f igures  2(b) and (c) a r e  f o r  nozzles with success ive ly  
increased atomization c a p a b i l i t i e s  b u i l t  i n t o  t h e i r  designs. Figure 3(a) shows 
t h e  change of v i s c o s i t y  of AMK fue l  a s  a function of shear  exposure t i m e  i n  a 
blender. 
changes due t o  temperature ( f ig .  3(b)) and a r e  i n  addi t ion  t o  t h e  temperature 
influence on v i scos i ty .  
For example, f i g -  
Changes i n  v i s c o s i t y  of t h i s  magnitude are s i g n i f i c a n t l y  higher than 
The very high-molecular-weight polymeric add i t ive  tends t o  clog small flow 
passages, screens,  f i l t e r s ,  and close-tolerance clearances i n  t h e  f u e l  control-  
ler. AMK f u e l  e x h i b i t s  the  g r e a t e s t  shear r e s i s t ance  and c r a s h - f i r e  r e s i s t ance  
125 
https://ntrs.nasa.gov/search.jsp?R=19800020818 2020-03-21T03:28:42+00:00Z
r i g h t  a f t e r  mixing and before any exposure t o  shear ,  such as pumping and flow 
through pipes,  f i t t i n g s ,  f i l t e r s ,  o r  o ther  components. Successive exposure t o  
any of t hese  shear  forces  tends t o  break t h e  polymeric molecules and thereby 
reduce the  average molecular weight and the  subsequent shear r e s i s t ance .  Con- 
t i nua t ion  of such degradation causes t h e  AMK t o  revert back toward the  o r i g i n a l  
proper t ies  of t he  base fue l .  
This c h a r a c t e r i s t i c  provides the  p o s s i b i l i t y  of using AMK i n  e x i s t i n g  en- 
gines by assur ing  a l e v e l  of degradation required f o r  acceptable performance 
f o r  each c r i t i c a l  component. I n  a n t i c i p a t i o n  of t h i s  poss ib le  requirement, t he  
United Kingdom i s  developing a f u e l  degrader t h a t  could be incorporated i n t o  
the  f u e l  system. The p r a c t i c a l i t y  of t h e  various ways t o  accommodate AMK f u e l  
i n  ex i s t ing  engines w i l l  be evaluated i n  t h i s  program. I f  i t  is determined 
t h a t  r e t r o f i t  modification of t he  f u e l  feed system would be required t o  accom- 
modate AMK f u e l  i n  e x i s t i n g  engines, the  ex ten t  of such modification requi re -  
ments w i l l  be i d e n t i f i e d  and evaluated. This w i l l  determine the  course of 
follow-on experimental work on AMK fue l .  
Antimisting kerosene i s  being considered as a j e t  f u e l  because 15 percent 
of t h e  t o t a l  f a c i l i t i e s  i n  a i r c r a f t  accidents r e s u l t  from postcrash f i r e .  Sig- 
n i f i c a n t  postcrash f i r e s  do not occur i n  acc idents  caused by f u e l  depletion. 
Simulated c rash  tests with AMK f u e l s  have demonstrated the  p o t e n t i a l  reduction 
i n  postcrash f i r e .  
can be used i n  turbofan j e t  engines without extensive modification. O f  s eve ra l  
addi t ives  t e s t e d ,  FM-9, developed by IC1 and the  RAE of Great B r i t a i n ,  was se- 
lec ted  f o r  f u r t h e r  evaluation. 
Fur ther  development e f f o r t  would be warranted i f  t h e  f u e l  
126 
0 MANAGEMENT TU\M - MINISTRY OF DEFENSE (MOD) AND DOTlFAA 
0 PROJECT RESPONSIBILITY - 
FU 
LA 
FU 
LO S DEVELOPMENT 
Y LElTER OF AGREEMENT 
CS-80-1618 
PROPULSION SYSTEMlAMK 
COMPATIBILITY EVALUATION 
TYPICAL ATOMIZATION OF JET A FUEL USING 
JT8-D STANDARD NOZZLE AT IGNITION FLOW RATES 
TF = 17' C 
Figure 1W 
127 
TYPICAL ATOMIZATION OF UNDEGRADED AMK IN 
JT8-D STANDARD NOZZLE AT IGNITION FLOW RATES 
TF = 13' C 
TYPICAL ATOMIZATION OF UNDEGRADED AMK IN 
JT8-D STANDARD NOZZLE AT CRUISE FLOW RATES 
TF = 14' C 
Figure 2(a) 
128 
TYPICAL ATOMIZATION OF UNDEGRADED AMK IN 
JT8-D LOW EMISSION NO 
TYPICAL ATOMIZATION OF UNDEGRADED AMK IN 
AIR BOOST NOZZLE AT CRUISE FLOW RATES 
Figure 2kl 
129 
.. .. 
VISCOSITY CHARACTERISTICS OF AMK 
CHANGE IN VISCOSITY WITH TIME IN BLENDER 
VISCOSITY 
RATIO 
TEMP, 77O F (25' C) 
VISCOSITY OF PARENT FUEL, 1.59 CP 
1.32 
C S - ~ O - ~ ~ Z O  
TIME IN BLENDER, hr 
Figure 3(al 
VISCOSITY CHARACTERISTICS OF AMK 
EFFECT OF TEMPERATURE ON VISCOSITY 
VISCOSITY 
12 r RATIO 
ASTM 
VISCOS ITY, 
CP 
TEMP, OC 
u 
-50 0 50 100 150 200 250 
TEMP, OF CS-80-1619 
Figure 3(b) 
130 


Antimisting kerosene

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