PPNS.1 Pressure Projection Algorithms for...
Transcript of PPNS.1 Pressure Projection Algorithms for...
PPNS.1 Pressure Projection Algorithms for INS
Pressure projection: INS methods enforcing only DMh
DMh: yiterativel0ε0 >≤⋅∇⇒=⋅∇ hh uu
“famous” named algorithms in the class include
MAC, SMAC – Los Alamos Nat. LabSIMPLE,- ER, -EC, -EST – Imperial College, UKPISO – Imperial College, UK Operator splitting – Univ. Houston Continuity constraint – Univ. Tennessee
fundamental PPNS theory ingredients
1. measure error in ∇h⋅uh via a potential function φh
2. employ φh to moderate DMh and/or DPh error via ⋅ velocity correction ⋅ pressure correction
3. iterate DPh + DMh until ε≤⋅∇ hh u 4. determine genuine pressure field
S e e k a s t r a t e g y t o i t e r a t e D M h + D P h f o r q = { u , p }
0Pe)(:D
0gReGrReδρ)(:D
0)(:D
1
110
0
=−⎟⎟⎠
⎞⎜⎜⎝
⎛
∂Θ∂
−Θ∂∂
+∂Θ∂
=Θ
=Θ+⎟⎟⎠
⎞⎜⎜⎝
⎛
∂∂
−+∂∂
+∂∂
=
=⋅∇=
−
−−
sx
uxt
E
xupuu
xtuu
M
jj
j
ij
iijij
j
ii
L
L
L
P
uρ
M arch DP h forward in tim e
definitionby0and
)(Re:TS
Denforcecantocorrectionaassumelikelyhoodallin0~:D
)(Reδρ
)(21~:TS
1
2*
11
*
1
2110
32
221
=⋅∇
Δ+∂∂
+⎥⎥⎦
⎤
⎢⎢⎣
⎡
∂∂
−∂∂
Δ−=
⇒⇒
≠⋅∇
Δ+⎥⎥⎦
⎤
⎢⎢⎣
⎡
∂∂
−+∂∂
Δ−=
Δ+∂∂
Δ+∂∂
Δ+=
+
−+
+
−−
+
ni
ij
nin
inj
j
ni
ni
n
n
j
ni
ijnn
inj
j
ni
n
i
n
ini
ni
u
tOxP
xuuu
xtuu
MPpM
tOxupuu
xtu
tOtut
tutuu
u
PPNS.2 Pressure Projection Foundation for INS
Subtracting the two TSs, one obtains
This explicit TS basis is theoretically inappropriate
( )
potentialMany
tO
tOPpx
tuu
h
nnn
nn
n
i
ni
ni
velocityaallymathematic isDinerrortheand
~!for~henceal,irrotationiscurlvanishingwithfieldvelocity
0)~()(toyieldssidesbothofcurlthetaking
)(ρ~
111
11
2
2*10
11
+++
++
−++
φ−∇=−
=−×∇
Δ
Δ+−∂∂
Δ−=−
uuu
uu
information from time n + 1 must be invoked for P* estimation ⇒ an iteration process is theory implied
PPNS.3 Pressure Projection Foundations for INS, Continued
T h eta - im pl ic i t T S i s m ore app ropr ia te , hen ce
)()1(:TS )(
1
1 θ
+
+ Δ+⎟⎟⎠
⎞⎜⎜⎝
⎛∂∂
θ−+∂∂
θΔ=− f
n
i
n
ini
ni tO
tu
tutuu
substituting INS DP yields
)(ˆReGr
ρ1
Re1)(
)1(
ˆReGr
ρ1
Re1)(
:TS
22
0
1
20
1
tOgxp
xu
xxuu
t
gxp
xu
xxuu
tuu
n
iij
i
jj
ij
n
iij
i
jj
ijnini
Δ+⎥⎥⎦
⎤
⎢⎢⎣
⎡Θ+
∂∂
+⎟⎟⎠
⎞⎜⎜⎝
⎛
∂∂
∂∂
−∂
∂Δθ−−
⎥⎥⎦
⎤
⎢⎢⎣
⎡Θ+
∂∂
+⎟⎟⎠
⎞⎜⎜⎝
⎛
∂∂
∂∂
−∂
∂Δθ−=−
+
+
Repeating this TS using guessed pressure P* at time n+1 produces 1
*
+niu
!)(:note
)(Re1
Re1
ˆ)(ReGr)ρ()(
)(:TSsngsubstracti
1*
)(
1
*
1*
21
0*
1
**
1*
0uu ≠−×∇
Δ+⎥⎥⎦
⎤
⎢⎢⎣
⎡⎟⎟⎠
⎞⎜⎜⎝
⎛
∂∂
⎟⎠⎞
⎜⎝⎛−⎟
⎟⎠
⎞⎜⎜⎝
⎛
∂∂
∂∂
Δθ+
Θ−Θ+⎥⎦
⎤⎢⎣
⎡∂−∂
Δθ+⎥⎥⎦
⎤
⎢⎢⎣
⎡
∂∂
−∂∂
Δθ=−
+
θ
+
+
++
+
n
f
nj
i
j
i
j
inninj
ij
j
ijnii
tOxu
xu
xt
gx
pPtxuu
xuutuu
PPNS.4 Pressure Projection Foundations for INS, Continued
I m p l i c i t T S i n d i c a t e s P P a l g o r i t h m m u s t b e i t e r a t i v e
close to iterative convergence, p + 1 divergence error at tim e n + 1 is solenoidal
1
1
11
* )(+
+
++ ∂
φ∂−≈−⇒
p
ni
pnii x
uu
then, convection and diffusion term s in θT S can be sim plified y ielding
p
ni
p
ni
p
nijj
j
p
ni
gx
pPtxx
ux
tx 1
*2
1
0*
1
2*
2
31
1
ˆ)(ReGr)ρ(
Re1
+++
+
+
Θ−Θ+∂−∂
Δθ+⎟⎟⎠
⎞⎜⎜⎝
⎛
∂∂φ∂
−∂φ∂
Δθ−≈∂φ∂
third term sim ply scales φ , and first term is intractable, hence assum e p
ni
p
ni xpPt
x1
0*1
1
)ρ(
+
+
+∂−∂
Δθ≈∂φ∂
integrating and setting integration constant to zero y ields
1
11
*
10
1ρ
+
++
+
φΔθ
+=p
n
p
n
p
nt
Pp
accounting for im possibility of p + 1 data affecting p th estim ation, assum e
∑=
+++
φΔθ
+=p
nn
p
n tpP
0α
1α1
01
* 1ρ
PPNS.5 Pressure Projection Foundations for INS, Continued
Iterating at t ime n + 1, divergence error in uh is solenodal
hence: φ−∇=−+ hn uu 1
divergence operation leads to the laplacian
0)( 2 =⋅∇+φ−∇=φ huL
BCs from φ definition affirm well-posedness
0ˆ)(ˆ)( 1 =⋅−−⋅φ−∇=φ + nuun hn
on ∂Ω for inflow, no-slip wall, 0ˆ)( =⋅φ−∇=φ n
ε<φ⇒⋅∇=φΩ∂E
hp
hhb ux via0)(,outflowforon
At iteration convergence at time n + 1, uh meets hDM bounded criterion
hence: 0)ˆ(Re,ˆ)(:BCs
0),(ρ)(:D2
210
=⋅∇+⋅∇=
=Θ−∇−=⋅∇ −
nun
P
fpp
uspp iL
PPNS.6 Pressure Projection Algorithm, Closure for DMh
PPNS.7 Pressure Projection INS PDE + BC System
For unsteady, laminar-thermal non-D INS in n-D
PDEs:
0ˆReGrEu)(
0)(
0Pe)(
0ˆReGrEuRe)(
22
2
21
221
=⎟⎟⎠
⎞⎜⎜⎝
⎛Θ+
∂∂
∂∂
−∇−=
=⋅∇+φ−∇=φ
=−Θ∇−∂Θ∂
+∂Θ∂
=Θ
=Θ+∂∂
+∇−∂∂
+∂∂
=
−
−
ij
ij
i
jj
ii
ij
ij
ii
xuu
xpp
sx
ut
xpu
xuu
tuu
g
u
g
L
L
L
L
BCs:
0)ˆ(Reˆ)(
0)(Nuˆ)(ˆ0:on
0)/,ˆ(Reˆ)(0
0),(ˆ)(:on0ˆ)(
givenusuallyon,,:on
21
walls
21
outflow
inflow
=⋅∇+∇⋅=
=Θ−Θ+Θ∇⋅=Θφ∇⋅==Ω∂
=∂∂⋅∇+∇⋅=
=φ=Θ∇⋅=Ω∂
=φ∇⋅=φΘΩ∂
−
−
nun
nn
nun
nn
x
fpp
utufpp
uq
pu
r
i
i
i
si
ref. Williams & Baker,IJNMF, Part B, V.29 (1996).
PPNS.8 GWSh + θTS for Pressure Projection INS
The PPNS PDE + BCs system contains familiar expressions
()θ−
θ
+−+
Δ+−=
=≡⇒
≡Δ+Δ=⇒θ+
⇒∪=≡≈
eeee
eeTeeee
eehN
N
Te
Tke
hN
QQQKK
QJJtQQ
QtQQ
tQtQNqqtq
}BCs{)}A,(b{}{]2M[Pa
}{]300M[}U{}QNP{]200M[}F{
and}0{}WS{SGWSGWS,then
}0{)}(RES{}]{MASS[}F{TSGWS
}TEM,3U,2U,1U{)}({and),)}({)}ζ,η(({),(for
1
x
eeeee
eehN
T
QQAKKQ
Qtq
}BCs{)}(b{}{]2M[Pa}AF{and},0{}WS{SGWSGWS
}PRS,PHI{}A{and...,),(for A
+−=≡=⇒
==x
31forCB,A,M available,are]M[matricesFE and ≤≤⇒ nbccdall e
PPNS.9 Newton Strategies for PPNS GWSh + θTS Algorithm
eepp QQ ]JAC[S]JAC[and}F{}δ]{JAC[: 1 ⇒−=+statementmatrixFor
Newton:
e
e
⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢
⎣
⎡
φφ0φφφ⋅⋅⋅
φ⋅⋅⋅φ⋅⋅⋅φ
=
JWJVJUJ0JTT
JWJWWJVJVVJUJUTJUWJUVJUU
]JAC[
quasi-Newton:
e
e
e ]J[;
JTTJWW
JVVJUTJUWJUVJUU
]JAC[ φφ
⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢
⎣
⎡
⋅⋅⋅⋅⋅⋅⋅⋅⋅
=
tensor product q-Newton: eeeee ]J[;]3J[]2J[]1J[]JAC[ φφ⊗⊗≈
explore these issues for the thermal cavity problem
PPNS.10 Iteration Strategy for PPNS GWSh + θTS Algorithm
P P N S i t e r a t io n s t r a te g y i s in d e p e n d e n t o f N e w to n c h o ic e
key formulation issues:
11
1
0
1α1
1*1
*1
)),((GWS
)(
)1iterationat,(D
)viaD(D
++
+
=
++
−+
+
ε<φ=
φΔθ+Φ=
+φ⋅∇=
=
∑∑
nE
phn
p
nn
hhhhn
hh
pp
tP
pfM
PMf
Lα
u
P
solution initiation: ICs for qh are never (!) available
for in
ˆΩ∂
⋅nu BCs:
cycleiterationrepeat,index,))((GWSsolve
dinitializeis),(,at
)(0
)0,D(Diterate
1
11
0α
1α1*1
0
npp
t
tP
pMf
h
h
E
p
p
n
hh
⇒
ε<φ
φΔθ+=
==
+
=
+−+ ∑
L
xu
P
∑=
+−+ φΔθ+=
=
⇒=
p
n
hh
h
tP
pMf
tpp
0α
1α1*1
0
0
)(0
),D(Diterate
)),(homogenous0)((GWSsolve
P
xL for outin,Ω∂
p BCs:
PPNS.11 PPNS Algorithm, SUM Φ - Pressure Interaction
PPNS algorithms usually neglect the genuine pressure PDE
recall:
0ˆReˆ)(:BCs
0ˆReGrEu)(:D
0ˆ)(:BCs0)(:D
21
2
2
=⋅∇+∇⋅=
=∂Θ∂
−∂
∂
∂∂
−∇−=⋅∇
=φ∇⋅=φ=⋅∇+φ−∇=φ
− nun
gP
nu
pp
xuu
xupp
M
iii
j
j
i
h
L
L
note: for Re >> 1 and Gr = 0, these PDE + BC systems have similar appearance
∑=
+−++ φΔθ+Φ≡Φ≅
p
nnnn tp1α
1α111 )(SUMSUM
however, for multiply-connected domains Ω, with distinct exit pressures, or Gr > 0 pn+1 ≠ SUMΦn+1
The accurate universal strategy is to run SUMΦ and solve for genuine p
ε>>ε<Φε<<φ +
E
hEE
p pandSUM,:assessmentaccuracy 1
For simply connected domains Ω, PPNS can run without p via
PPNS.12 {FQ}e Template Essence for GWSh + θTS PPNS Algorithm
GWSh + θTS for PPNS initial-value PDEs
θ− +−+
Δ+−=
]}BCs{)}(b{}{]2M[Pa
}{]300M[}U[{}QNP{]200M[}F{1
eeee
eeTeeee
QQKK
QJJtQQ
template essence:
θθ−
θ
−−Δ+
Δ+−=
)}(b{}QN,P]{2M)[1;E,E)()()(Ra,(
}QN,P]{300M)[0;E}(U){)((}QNP]{200M)[1;0}(){)((}F{
1 QQIJJKIKt
QKKJJtQQ e
for {Q}e ⇒ {UI}e:
θΔ+
Δ++=
}TEMP]{200M)[1;0}(){)(GDOT,Re/Gr,(}PRESN]{20M)[0;E}(){)((
}SPHINPHI]{20M)[0;E}(){)(()}U(b{
2 ItKKIt
KKII e
for {Q}e ⇒ {TEMP}e:
θ
θ
−Δ+
Δ=
}TREFTEMP]{200N)[1;0}(){)(Pe,Nu,(
}SRC]{200M)[1;0}(){)(()}TEMP(b{1-t
te
PPNS.13 [JAC]e Template Essence for GWSh + θTS PPNS Algorithm
The Newton jacobian for {QI} in DPh , I not summed
]][200M)[1;0}(){)(GDOT,Re/Gr,(]JAC[
]][20M)[0;E}(){)((]JAC[]][003M)[0;IE}(UI){)((
}U{/}FU{]JAC[]][2M)[1;E,E}(){)(Re,(
][]003M)[0;IE}(UI){)((]][300M)[0;E}(U){)((
]][200M)[1;0}(){)((}U{/}FU{]JAC[
2
1
ItI
KKIIJJt
JIIJIJJKIKt
KKtKJKJt
IIII
e
e
e
eee
Δ=Θ
=φΔ=
∂∂=−Δ+
Δ+Δ+
=∂∂≡
−
PPNS.14 Quasi-Newton TP Jacobian for PPNS GWSh + θTS
G W S h + θT S v i a { N k+ (η ) } e n a b l e s T P j a c o b i a n c o n s t r u c t i o n
Newton , n = 2 Tensor product , n = 2
JACOBIANS U1 U1 1 1 ( ) ( ) { }( ; 1)[B200][ ] U1 U1 2 1 + ( ) ( ) {U1+U2} (1020; 0) [B3001] [ ] + ( ) ( ) {U1+U2} (3040; 0) [B3002] [ ] + ( ) ( ) {U1} (1; 0) [B3100] [ ] + ( ) ( ) {U1} (3; 0) [B3200] [ ] + (REI) ( ) {RETL} (1122;-1) [B3011] [ ]+ (REI) ( ) {RETL} (1324; -1) [B3012] [ ]+ (REI) ( ) {RETL} (1324; -1) [B3021] [ ]+ (REI) ( ) {RETL} (3344; -1) [B3022] [ ] U1 U2 2 1 ( ) ( ) {U1} (2; 0) [B3100] [ ] + ( ) ( ) {U1} (4; 0) [B3200] [ ] U2 U1 2 1 ( ) ( ) {U2} (1; 0) [B3100] [ ] + ( ) ( ) {U2} (3; 0) [B3200] [ ] U2 TEMP 2 2 (-,GR, RE2I) ( ) { } (0; 0) [B200] [ ]
JACOBIANS U1 U1 1 1 DIRECTION 1 ( ) ( ) { }( ; 0)[A200][DETJ] U1 U1 2 1 DIRECTION 1 + ( ) ( ) {U1+U2} (1020; 0) [A3001] [ ] + ( ) ( ) {U1} (1; 0) [A3100] [ ] + (REI) ( ) {RETL} (1122; -1) [A3011][ ] U1 U2 2 1 ( ) ( ) {U1} (2; 0) [A3100] [ ] U2 U1 2 1 ( ) ( ) {U2} (1; 0) [A3100] [ ]
U1 U1 1 2 DIRECTION 2 ( ) ( ) { } ( ; 0) [A200] [DETJ] U1 U1 2 2 DIRECTION 2 ( ) ( ) {U1+U2) (3040; 0) [A3001] [ ] + ( ) ( ) {U1} (3; 0) [A3100] [ ] + (REI) ( ) {RETL} (3344; -1) [A3011] [ ] U1 U2 2 2 ( ) ( ){U1} (4; 0)[A3100] [ ] U2 U1 2 2 ( ) ( ) {U2} (3; 0) [A3100] [ ] U2 TEMP 2 2 (-.GR, RE2I) ( ) { } (0; 0) [A200] [DETJ]
Thermal cavity, Ra = 106 , M = 322 non-uniform Ωh, best mesh solution
Thermal cavity, Ra = 106 , M = 322 uniform Ωh, various jacobians
PPNS.15 GWSh + θTS ⇒Newton, q-Newton Performance Summary
TS exercise on L (q) generates a kinetic flux vector jacobian matrix
DP, DE:
qfqufxqqxfq
qsxqqu
xtqq
jjjjj
jtjjt
jj
j
∂∂≡≡∂∂
+⇒∂∂+≅
=−⎟⎟⎠
⎞⎜⎜⎝
⎛
∂∂
−∂∂
+∂∂
= −
/Aand,A/
0)(Pa)( 1L
TS:
⎥⎦
⎤⎢⎣
⎡⎟⎟⎠
⎞⎜⎜⎝
⎛∂∂
∂∂
+⎟⎠⎞
⎜⎝⎛
∂∂
∂∂
∂∂
=⋅⋅⋅⋅=
⎥⎦
⎤⎢⎣
⎡∂∂
+∂∂
∂∂
=⋅⋅⋅⋅=
∂∂
−=
Δ+Δ+Δ+Δ+=+
xq
xtq
xxq
xq
tq
xq
xqq
tOqtqttqqq
kjk
kjkj
ttt
kkjj
jtt
jjt
nttt
ntt
nt
nn
AAAμAAγ
AβAαA
A
)(612/1 4321
Substituting into TS, taking lim (TS) ⇒ ε > 0 produces
DP, DE:
0AAA3
μAβA2
AA3
γαA2
)()(
=⎥⎦
⎤⎢⎣
⎡⎟⎟⎠
⎞⎜⎜⎝
⎛∂∂
∂∂Δ
+∂∂
∂∂Δ
−
⎥⎦
⎤⎢⎣
⎡⎟⎠⎞
⎜⎝⎛
∂∂
∂∂Δ
+∂∂
∂∂Δ
−=
llkj
kkkj
j
kjk
jj
m
xq
xt
xq
xt
tq
xt
tq
xtqq LL
PPNS.16 GWSh ⇒ TWSh + θTS for PPNS, Accuracy, Stability
TWSh requires Aj, AjAk and AjAkAl be formed for INS
⇒ for q = {ui, Θ}: (i not summed)
⎥⎦
⎤⎢⎣
⎡ +++=
⎥⎦
⎤⎢⎣
⎡ +⎥⎦
⎤⎢⎣
⎡ +=
⎥⎦
⎤⎢⎣
⎡ +≡
⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢
⎣
⎡
++
+
=⇒
kj
kjjkkjkj
k
kk
j
jjkj
j
jj
j
j
j
j
jj
uuuuuuuuuu
uuu
uuu
uuu
uuu
uuuu
,00,δδδδ
,00,δ
,00,δ
]AA[
,00,δ
0
0
]A[A
iiiiiiii
iiii
ii
3
2
1
Since [Aj] is diagonal, generates no q cross-coupling and
⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢
⎣
⎡
∂Θ∂
∂
∂+
∂∂
∂∂
=⎥⎦
⎤⎢⎣
⎡∂∂
∂∂
kkj
k
jki
k
ikj
jkkj
j
xuu
xu
uuxuuu
xxq
x ,0
0,AA
PPNS.17 TWSh + θTS for PPNS, Kinetic Flux Vector Jacobian
The TS lead β-term for q = {ui} has been generated many ways
[ ] [ ]kjkj uutt2βAA
2β:ydiffusivittensorbalancing Δ
≅Δ
toleads/2/scaletimelocaldefining eht u≈Δ
[ ] [ ]
)ˆtoparallel(:uniformnon
)(detC:uniform
ˆβAA2β:GalerkinPetrov
1
jeh
ne
h
kjkj
uhfh
h
uuht
⇒Ω−
≅Ω
≅Δ
−
[ ] yidenticallgeneratesINSstatesteadyonexerciseTS,1Refor kjuu−>>
analyzednotis:uniformnon
!arbitrarynot)(detC,12Re/β:uniform 12
eh
ne
h
hh
hh
⇒Ω−
≅⇒Ω
PPNS.18 TWSh + θTS for PPNS, Alternative β-Term Forms
Thermal cavity for 106 < Ra ≤ 108 requires Newton algorithm
Thermal cavity, Ra ≤ 106 is intrinsically dispersion-error free for M ≥ 322
PPNS.19 GWSh ⇒ TWSh + θTS for PPNS, Thermal Cavity
Optimal solution estimates, 106 ≤ Ra ≤ 108 (Mitra, 2000)
Newton for TWSh + θTS enabled by Krylov solvers, best mesh estimate
Norm TWSh, Ra = 106 dVD LeQ TWSh, Ra = 107 LeQ TWSh, Ra = 108 LeQ M 32(qN) 32 64 (1983) (1991) 32 64 (1991) 32 64 128 (1991) ψmid 15.48 16.87 16.37 16.32 16.38 0.010 0.009 0.009 0.000564 0.00522 0.0053 0.00523
umax z
76.02 0.85
70.93 0.85
64.80 0.85
64.63 0.85
64.83 0.85
0.064 0.85
0.045 0.88
0.047 0.88
0.00306 0.93
0.0322 0.926
0.0322 0.926
0.0322 0.928
wmax x
209.11 0.04
213.32 0.04
219.33 0.04
219.36 0.038
220.60 0.038
0.206 0.02
0.219 0.02
0.221 0.02
0.207 0.01
0.221 0.01
0.222 0.01
0.222 0.012
E
hφ 5E-5 5E-8 5E-8 --- 5E-9 2E-6 5E-8 5E-9 2E-5 2E-7 2E-7 5E-8
PPNS.20 TWSh + θTS for PPNS, Optimal, Best Mesh Solutions, Ra ≤ 108
8:1 thermal cavity flowfield transitions to unsteady for Ra > 3.1E5
Graded 40 × 200 Ωh to scale & rectangularized GWSh + θTS steady solution, θ = 0.55, Ra = 3.4E5
Continuation at θ = 0.5 after 100Δt Periodic solution snap shot
PPNS.21 TWSh + θTS for PPNS, Thermal Cavity Validation
TWSh solution Re = 800, β = 0.1, n = 3
Primary recirculation, n = 2 Primary recirculation, n = 3
PPNS.22 TWSh + θTS, Laminar Step-Wall Diffuser Validation
o - TWSh nodal data lines - experimental data
xs
= 6.2
xs
= 9.3
Streamwise (U) velocity
PPNS.23 TWSh + θTS Step-Wall Diffuser Validation, Re = 648
o - TWSh nodal datalines - experimental data
xs
= 12.3
xs
= 18.9
Streamwise (U) velocity
PPNS.24 TWSh + θTS Step-Wall Diffuser Validation, Re = 648
oil flow streaklinesnear floor
oil flow streaklines near lid
transverse plane velocity vectors, x/S = 7.7
PPNS.25 TWSh + θTS, Step-Wall Diffuser, Flow Characterization
Lagrangian particle tracks, sized by elevation
Re = 389
Re = 648
PPNS.26 TWSh + θTS, Step-Wall Diffuser, Flow Characterization
From INS.1, unsteady, Reynolds-averaged turbulent (TKE) INS system
DM: ∇⋅u = 0
DP: ( ) 0guuuu=Θ+∇+⋅∇−∇+∇⋅+
∂∂ − ˆ
ReGrReEu 2
1 tvpt
DE: ( ) 0u =−Θ∇+⋅∇−Θ∇⋅+∂Θ∂
Θ−− sv
tt11 PrPe
DE(k):
DE(ε):
( ) 0uTu =−∇+∇+⋅∇−∇⋅+∂∂ − εPrPe 1 kvk
tk tt
( ) 0uTu =−∇+∇⋅∇−∇⋅+∂∂ k
kv
ttt /εCεCεPrCεε 22
ε1εε
PPNS iterative closure strategy
0ˆ)(ˆ)(0)(
1
2
=⋅−−⋅φ−∇=φ
=⋅∇+φ−∇=φ+ nuun
uhn
hLDMh:
∇⋅DP: 0)ˆ(Re,ˆ)(
0),(ρ)(2
210
=⋅∇+⋅∇=
=Θ−∇−= −
nun fpp
uspp iL
PPNS.27 TWSh + θTS for PPNS, Closure for Turbulent Flow
u
n
y+
In n -D , low R e t r eg io n reso lu t io n i s com puta t iona l ly in tense
υ/
B)Elog(κ/U
τ
1
yuy
yuu
≡
+=≡+
+−+τ
recall Cole’s law:
k
uy
Cuk
yu
w
t
μ
3τ
1
μ2τ
τ
Cτ
)κ(
/
κυ
=
=ε
=
=
−
DEm(k) ⇒
for near-wall production = dissipation
law-of-the-wall BC strategy
!mandatorycheckyconsistancnode1walleachatforsolutionrequires
)(Dfrom,)(,
0)(
τ
1wall
wall
⇒+
ε=ε
=
+
ukEknk
num
is
PPNS.28 BCs for n-D TKE Closure, Law-of-the-Wall
+u BEynuu ≡⎟⎟⎠
⎞⎜⎜⎝
⎛ + + 1 = / κτ
Bradshaw BL in similarity coordinates
U
y/u =y υ+ τ
U
PPNS.28A Turbulent BL Similarity BCs
Turbulent BL similarity
TWSh + θTS for qh ⇒ {U1, U2, U3, T, PHI; K, EPS, TIJ: PRES}T
q-Newton [JAC]e :
e
eijijijij
ij
ij
e
]JPP[;TJT,EJT,KJT
JET,JEE,JEKJKT,JKE,JKK
;
J,0,WJ,VJ,UJ0,JTT,JTW,JTV,JTU
JW,JWT,JWW,JWV,JWUJV,0,JVW,JVV,JVUJU,0,JUW,JUV,JUU
⎥⎥⎥
⎦
⎤
⎢⎢⎢
⎣
⎡
⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢
⎣
⎡
φφφφφ
φφφ
note: for laminar flow yields genuine Newton ⇔ Krylov solver
Iteration stabilization accrues to state variable update delay
loopiterationrestart}PRES{forsolve},2{},1{foreconvergencat
)}N1(2F{}2F{:}T,EPS,K{}2{for
)}N2(1F{}1F{:},T,U{}1{for
1+
==
=φ=
n
peeij
Te
pee
Te
QQQQ
QQQIQ
Template essence follows in aPSE file
PPNS.29 TWSh + θTS PPNS Algorithm q-Newton Template Essence
Laminar duct flow, Re/L = 1000: stability, φ, Σφ, pressure
GWSh, β = 0, u1h φh, E-05
TWSh, β = 0.2, u1h
Σφh, E-05 Pressure, E-04
φh, E-05 Σφh, E-05 Pressure, E-04
PPNS.30 GWSh ⇒ TWSh + θTS PPNS Algorithm, Performance of Theory
Turbulent duct flow, Re/L = 4 ×106, β = 0.2; φ, Σφ, pressure, k, ε
Pressure, E 02 φ, E-04 Σφ, E-04
Re-turb, E 04 TKE, E-01 Dissipation, E-04
PPNS.31 GWSh ⇒ TWSh + θTS PPNS Algorithm, Performance of Theory
RaNS + TKE turbulent entrance duct TWSh solution
PPNS.31A RaNS Dissipative Flux Vector Distributions
RaNS + TKE turbulent entrance duct TWSh solution
PPNS.31B RaNS Dissipative Flux Vector Distributions
RaNS + TKE turbulent entrance duct TWSh solution
PPNS.31C RaNS Dissipative Flux Vector Distributions
RaNS + TKE turbulent entrance duct TWSh solution
PPNS.31D RaNS Dissipative Flux Vector Distributions
RaNS + TKE turbulent entrance duct TWSh solution
PPNS.31E RaNS Dissipative Flux Vector Distributions
RaNS + TKE turbulent entrance duct TWSh solution
PPNS.31F RaNS Dissipative Flux Vector Distributions
Turbulent duct flow, Re/L = 4 ×106, BC resolution, iterative convergence
Mesh resolution y+ distribution Iteration convergence
Computer lab 7:
analyze turbulent entrance duct flow inviscid onset to a duct φ, Σφ, p onset effects now interior to Ω k, ε, τij distributions sharply defined x
PPNS.32 TWSh + θTS PPNS Algorithm, Performance of Theory
flux
ΩPPNS ΩDEh
Flow in externally heated ducts known as “conjugate heat transfer”
Δt = 0.2s steady state ss perspective
Solution domain has double span: BCs for PPNS applied at wall BCs for DEh are external ⇒ DEh solved in fluid and duct walls
Turbulent duct flow, Re/L = 3×106, Gr/Re2 = X, temperature distributions
Δt = 0.4s
PPNS.33 TWSh + θTS for Conjugate Heat Transfer
Duct networks with multiple outlets demand pressure BCs
φ, Σφ only
2:1 exit area branching duct flow
0)ˆ(Re,ˆρ)(
0),(ρ1)(DPPNSrecall
210
2
0
=⋅∇+∇⋅=
=Θ+∇−=⇒⋅∇
− nun
uP
fpp
spp iL
φ, Σφ, pressure
PPNS.34 TWSh + θTS PPNS for Bifurcating Duct Flows
Bronchial tree simulation experiment (Ericson, 2004)
validation model cross-sections
section B-B
section A-A section D-D
section C-C section E-E section F-F
PPNS.35 TWSh + θTS PPNS for Bifurcating Duct Flows
Ill-posedness of DM + DP for INS resolved by PP theory
TWSh + θTS algorithm performance for PPNS formulation
Tiji pkutq };τ,,,,,{),( εφΘ⇒xstate variable:
PP strategy:
0)ˆ(Re,ˆ)(0),(Eu)(D
0and,0ˆ)(0)(D
2
2
2
out
=⋅∇+∇⋅=
=Θ∇−∇−=⇒⋅∇
=φ=φ∇⋅=φ
=⋅∇+φ−∇=φ⇒
Ω∂
nunuuP
nu
fppspp
M h
L
L
BCspressurerequireflowsgbifurcatinacceptableeconvergencNewton-quasi
onverificatiBCwall-the-of-law
modelclosureτalgebraic),(employ flowsductturbulent
)(δεε,confirms10Raforbenchmarkcavitythermal
CdataC)(
basis1,confirmedeconvergencasymptotictheorylinear
2conv
8
2
1H0)(2
2L2
ij
hh
ft
keE
h
k
Q
qthtne
k
+ε
<<⋅∇≤
Δ+≤Δ
=θ
u
PPNS.36 Summary, TWSh + θTS PP INS Algorithm