Studies to characterize dilution zone mixing; experiments on the effects of free-stream turbulence on a jet in crossflow; and the development of an interactive computer code for the analysis of the mixing of jets with a confined crossflow are reviewed

Holdeman, J. D.

English

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DILUTION ZONE M I X I N G  
James D. Holdeman 
NASA Lewis Research Center 
Cleveland, Ohio 44135 
Motivated by considerations of dilution zone mixing in gas 
turbine combustion chambers, NASA sponsored, in 1972 - 1975 
contract and grant studies of the mixing characteristics of a 
row of jets injected normally into a duct flow of a different 
temperature (references 1, 2, & 3). Based on the favorable 
response to these studies, and the areas for further work which 
they identified, NASA Lewis is currently conducting a balanced 
program of contract, grant, and in-house research on various 
aspects of the 'jet in a confined crossflow' problem. Included 
in these are: 1) development of .inteFactive computer codes for 
analysis of dilution jet mixing, and 2) extension of the 
experiments on jets in a confined crossflow, 
From the data of References 1 & 2, an empirical model was 
developed (refs. 4 & 5 )  to describe the observed temperature 
distributions. The current interactive code provides a 3-D 
pictorial representation of the temperature, as given by these 
correlations, for any user-specified downstream location, flow, 
and orifice parameters. Although calculations can be performed 
for (almost) any flow and geometric conditions of interest, they 
are, of course, most reliable for conditions within the range of 
the experiments. These codes will be improved and extended, and 
options added, as new data become available. 
The experiments in References 1 to 3 dealt primarily with a 
single row of jets mixing into an isothermal flow in a constant 
cross-section duct. Variations in the mixing were observed as a 
function of jet-to-mainstream momentum ratio, orifice size, and 
spacing. The current experiments examine perturbations of this 
problem characteristic to gas turbine combustion chambers, 
namely: f 1 ow area convergence, non-i sothermal mainstream flow, 
and opposed in-line and staggered injection. 
Specifics of grant studies on free-stream turbulence effects and 
reverse flow geometries, and analytical calculations of jets in 
crossflow are presented in companion papers at this conference. 
https://ntrs.nasa.gov/search.jsp?R=19830020945 2020-03-22T00:50:48+00:00Z
REFERENCES 
1. Walker, R.E. and Kors, D.L.: Multiple Jet Study Final 
Report. NASA CR-121217, 1973. 
2. Holdeman, J.D., Walker, R.E., and Kors, D.L.: Mixing of 
Multiple Dilution Jets with a Hot Primary hirstream for Gas 
Turbine Combustors. AIAA Paper 73-1249, 1973. 
3. Kamotani, Y. and Greber, Isaac: Experiments on Confined 
Turbulent Jets in Cross Flow. NASA CR-2392, 1974. 
4. Walker, R.E. and Eberhard, R.G.: Multiple Jet Study Data 
Correlations. NASA CR-134796, 1975. 
5. Holdeman, J.D. and Walker, R.E. : Mixing of a Row of Jets 
with a Confined Crossflow. AIAA Journal, vol. 15, no.2, 
Feb.1977, pp243-249. 
DILUTION ZONE M I X I N O  STUDIES 
O B J E C T X V E  - TO C H - R - C T E R X Z E  DILUTION 
ZONE H X X X N Q  I N  SUFFICIENT 
D E T C I X L  TO. 
L X D E N T X F Y  AND UNDERST-ND TkE 
D O W I N - N T  P H Y S I C - L  H E C H - N X S M S  
Q O V E R N X N Q  THE H X X X N Q  PROCES8 
* REFXNE AND EXTEND E W P X R X C ~ L  
HODELS TO PROVIDE NEAR-TERH 
COMBUSTOR D E S X Q N  TOOL 
f PROVIDE A DATA B C 8 S E  FOR 
V E R I F I C - T Z O N  OF A N - L Y T X C a L  
MODELS 
D I L U T I O N  ZONE M I X I N Q  STUDIES 
t EXPERIMENTS ON EFFECTS OF 
FREE-STREAM TURBULENCE ON A J E T  
I N  CROSSFLOW CMSU =RANT> 
t EXPERIMENTS ON D ILUTXON J E T S  I N  
REVERSE FLOW COMBUSTOR OEOMETRIES 
CCWRU GRANT, 
* DEVELOPMENT OF INTERACTIVE 
CODES FOR EVALUATION OF 
DESIGN ALTERNATIVES <IN-HOUSED 
* EXPERIMENTS ON J E T S  I N  A CONFINED 
CROSSFLOW (GARRETT CONTRACT, 
t ANALYTICAL  CALCULATIONS OF 
J E T S  I N  CROSSFLOW <IN-HOUSE> 
DXLUTXON ZONE DESION COMPUTER PROQRAWS 
OBJECTIVEm DEVELOPMENT OF XNTERF8CTXVE 
COWPUTER CODE FOR ANALYSIS  
OF H I X I N O  OF J E T S  W I T H  A 
CONFXNED CROSSFLOW 
FEATURE58 PROVIDES A 3-D P I C T O R I A L  
REPRESENTATION OF THE 
TEMPERATURE F I E L D  
PURPOSE8 EVALUATE EFFECTS OF VARVINQ 
FLOW AND QEOMETRV 
QUIDtE DESIQN TO REDUCE 
DCZVELOPHENT TIME AND COQT 
BTATUS8 CODES W I L L  B E  IMPROVED aND 
OPTIONS ADDED AS NEW DATA 
BECOME A V A I L A B L E  
TOP 
UIEW 
SIDE 
VIEW' 
Jet in a Confined Crossflow 
Typical Temperature Profile Distribution in Y - Z Plane 
V a r i a t i o n  i n  T e m p e r a t u r e  D i s t r i b u t i o n s  w i t h  D o w n s t r e a m  D i s t a n c e  
0 
1 
0 1 0 1 
THETA = (T, - T)/(T, - T ~ )  
Varations in Temperature Distributions with 'Momentum Ratio 
0 1 0 1 0 1 
THETA = (T- - T)/(T- - T,J) 
Variation in Temperature Distributions with Orifice Size 
at Constant Spacing to Height Ratio (S/H = .5; J = 32) 
DXLUTXON J E T  MXXXNQ PROQRAW 
O B J E C T I V E  - EXTEND KNOWLEDQE OF 
PENETRATION AND MIXXNO 
- P R O V I D E  A DATCI BASE T O  
V A L I D A T E  COMBUSTOR 
ANALYTXCAL MODELS 
APPROACH - PERFORM EXPERXMENTS AND 
EXTEND EMPXRXCAL 
CORRELATXONS TO MODEL. 
f NON-ISOTHERMAL HAINSTREAH 
f FLOW CONVEROENCE 
OPPOSED & BTAOQERED J E T S  
a) . . H o t  Jets - Ambien t  M a i n s t r e a m ;  DR=..75, J=31, R=6.4 
b) Ambien t  Jets - H o t  M a i n s t r e a m ;  .DR=2.2, Js26, R=3.5 
c) A m b i e n t  Jets - H o t  M a i n s t r e a m ;  DR=2.3, ~ ~ 1 0 9 ,  R = ~ . v  
Effect of D e n s i t y  R a t i o  on ~ e m ~ e r a t u r e  P r o f i l e s  (S/D=4, H/D=B) 
- 
XMD= P.000 
X/OJ = 10.24 
'L- 
a) H o t  Jets - Ambient Mainstream;  DR=.62, 5=31, H=3.8 
b )  Ambient Jets - H o t  Mainstream;  DRn2.1, Jr21.6, M=6-3  . 
c) Ambient Jets - H o t  Mainstream;  , DR=2.1, J=5.7, Hz3 .2  
. . 
Eff  ect of D e n s i t y  R a t i o  on T e m p e r a t u r e  P r o f  i 1 es (S/D=2, H/D=4) 
a) Isothermal 
0 
b) Top C o l d  
C )  Top Hot 
a-%%:o:-%5: ,:-%I v v v  p 
Influence of non-unifofm Mainstream on Temperature Prof i les  
m. 2.m 
MI x 0.74 
xmJ n 2-43 
)L- k W '  IL- 
U R l t  4-87 
a) Straight.  Duct 
b) Symmetric Convergence (.5/1) 
C )  Injection Wall Converging <.5/1) 
Inf luence of  Flow Area Convergence on Temperature P r o f i l e s  
a) Single-side (top) Injection (S/H=.5, J=26.3) 
b) Two-side (opposed) Injection (S/H=. 25, J=25) 
Comparison Between Single-side and Opposed Jet Injection 


Dilution Zone Mixing

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