cites 2005, novosibirsk modeling and simulation of global structure of urban boundary layer...
TRANSCRIPT
CITES 2005, Novosibirsk
Modeling and Simulation of Global Structure of Urban Boundary Layer
Kurbatskiy A. F.Institute of Theoretical and Applied Mechanics of
SB RAS, Novosibirsk, Russia
CITES 2005, Novosibirsk
O U T L I N E:
Motivation
Introduction
Urban Boundary Layer
Improved Model for the Turbulent ABL
Urban Heat Island in a Calm and Stably Stratified Environment
Impact of UHI on the Global Structure of the ABL
Impact of the UHI and the UCL on the ABL Structure
Conclusions
CITES 2005, Novosibirsk
Motivation
The aim of lecture consists in a statement of the improved turbulence model for the urban boundary layer and results of its verification in the simple 2D cases.
CITES 2005, Novosibirsk
Introduction
●Complexity of simulation of urban air quality problems consists in the necessary of resolution the variety spatial-temporal scales over which the phenomena proceed.
●The two most important scales include: an 'urban' scale of a few tens kilometers (a
typical scale of city) where large amounts of contaminants are emitted, and
a 'меsо' scale of a few hundreds of kilometers where secondary contaminants are formed and dispersed.
CITES 2005, Novosibirsk
Introduction● In order to compute the mean and turbulent
transport and the chemical transformations of pollutants, several meteorological variables, such as wind, turbulent fluxes, temperature etc., it is necessary to known as more as possible precisely.
These meteorological variables can be calculated by an improved model for the turbulent ABL.
● The two most important effects of the urbanized surface have an influence on the air flow structure:
Differential heating of the urbanized surfaces which can generate the so-called urban heat island effect.
Drag due to buildings.
CITES 2005, Novosibirsk
The development of ABL over flat terrain
The development of ABL over flat terrain
The potential temperature θ and wind velocity U are shown forthe convective and stable boundary layers.
CITES 2005, Novosibirsk
Urban Boundary Layer
CITES 2005, Novosibirsk
Improved Turbulence Model for the ABL
CITES 2005, Novosibirsk
12 ;i
i ijk j kj i
ij
DU Pg U
Dt x x
,jj
D
Dt xh
ij i jτ < u u > is th e Reynolds stress
i ih < u θ > is the heat f lux
.
GOVERNING EQUATIONS FOR TURBULENT PBL
CITES 2005, Novosibirsk
Turbulence equations
ijijijjiijijij ПhhPDDt
D
k
ijk
k
jikij x
U
x
UP
kk
iji
jj
iij pux3
2
x
pu
x
puП
ijk
j
k
iij 3
2x
u
x
u2
ii g
kijkji
kij pu
3
2uuu
xD
,Пxx
UhD
Dt
Dhi
2i
jij
j
ij
hi
i
,x
pП
ii
jij
hi uu
xD
i jReynolds stress, u u ij
i iHeat flux, h u θ
CITES 2005, Novosibirsk
An updated expressions for the pressure-velocity Пij (= Пij
(1)+ Пij(2)+ Пij
(3)) and the pressure-temperature
Пiθ (= Пiθ(1)+ Пiθ
(2)+ Пiθ(3)) correlations
Mellor-Yamada model (1982, Mellor, 1973):
Пij(1)=Cτ-1bij
Пij(2)~-ESij most of rapid terms are neglected
Пij(3)=0 no buoyancy effects are included
Пiθ(1)=C1θhi, Пiθ
(2)=0, Пiθ(3)=C3θβ<θ2>,
(E=1/2<uiui> is TKE; Sij=(Ui,j+ Uj,i)/2)
CITES 2005, Novosibirsk
An updated expressions for the pressure-velocity Пij (= Пij
(1)+ Пij(2)+ Пij
(3)) and the pressure-temperature Пiθ (= Пiθ
(1)+ Пiθ(2)+ Пiθ
(3)) correlationsLaunder’s model (1975)
Present model (2001)
Пij(1)= C1τ-1bij
Пij(2) =-4/3C2ESij - C2(Zij+Σij)
Пij(3) = C3Bij
Пiθ(1) = C1θ τ
-1hi , Пiθ
(2) =-C2θhjUi,j , Пiθ
(3) = C3θβi<θ2>
Σij=bikSij+Sikbkj-2/3δijbkmSmk;
The model constants of Пij are
C1, C2, C3, C1θ, C2θ= C3θ
Zeman and Lumley model (1979)
Canuto et al. model (2002) Пij
(1)= C1τ-1bij
Пij(2)=-4/5ESij - α1Σij- α2Zij
Пij(3) =(1-β5)Bij
Пiθ(1) = C1θ τ
-1hi , Пiθ
(2) =-3/4α3(Sij+5/3Rij) hj , Пiθ
(3) =γ1βi<θ2>
Zij=Rikbkj-bikRkj; Bij=βihj+ βjhi- 2/3δijβkhk
CITES 2005, Novosibirsk
Level-3 Algebraic Models for Reynolds Stress and Scalar Fluxes
ij3ijij2ij1ij BSEb
ijijijijijijij ПBSE3
40Db
Dt
D
,Пxx
Uh0D
Dt
Dhi
2i
jij
j
ij
hi
i
2
3i4j
ijijjij gx
E3
2bhA
Coupled algebraic system equations for and jiuu :uh ii
CITES 2005, Novosibirsk
Level-3 Fully Explicit Algebraic Models for
Reynolds Stress and Scalar Fluxes : 2D case
, ,M
U Vuw vw K
z z
H cw Kz
M MK E S
H HK E S
2 22 6 5
1 21 ( )
3c M HG s G gD
2
HG N 2
MG S2N g
z
2 22 U V
Sz z
HHM62H5
2H4HM3H2M1 G)GGdGd(GdGGdGdGd1D
E
E/gGs1
ssGssGs1s
D
1S
2H6
54H32H10M
6
1
1 2 11
3H HS s GD c
CITES 2005, Novosibirsk
Three-parametric turbulence model
:uu)2/1(E,)TKE(energykineticTurbulent ii
2Temperature var iance , :
,hx
UD
2
1
Dt
DEii
j
iijii
,E
DDt
D 2
,x
Uh
E2h
x
Ub
j
iij3i
i2
j
iij10
jj ux/D E3/2uub ijjiij
,2x
h2DDt
D
ii
2
2
2jx/
2ii ux/D
i
2
Eiii x
EEc
xD
2
1
i
2
aia x
aEc
xD
2,a
,2
2
ER
E2R
2
TKE dissipation,
CITES 2005, Novosibirsk
Air Circulation above an Urban Heat Island
in a Calm and Stably Stratified Environment
CITES 2005, Novosibirsk
Air Circulation above an Urban Heat Island
CITES 2005, Novosibirsk
Thermal circulation above an urban heat island
Experiment
of Lu et al. (JAM.1997.V.36)
Computation by three-parametric
turbulence model
(Kurbatskii A.
JAM. 2001. V.40)
CITES 2005, Novosibirsk
(A. F. Kurbatskiy, J. Appl. Meteor. 2001. V. 40. №10)
26.5 26.5
27
27.5
28
28
28
28
.5
28.5
28
.5
29
29
29
29
29 29
29.5
29.5
29.5
29.5
30
30
30
30.530.5
3131
31.531.5
3232
32.532.5
30
33 33
28.5
32.5
32
27.5
27
2626
28
r / D
Z/Z
i
-1.5 -1 -0.5 0 0.5 1 1.50
0.5
1
1.5
CITES 2005, Novosibirsk
Dispersion of passive tracer above UHI in a Calm and Stably Stratified Environment
0.2
0
0.05
0.2
0
0.150.15
0.15 0.150.100.10
0.05
r / D
Z/Z
i
-1.5 -1 -0.5 0 0.5 1 1.5
0.5
1
1.5
CITES 2005, Novosibirsk
Impact of a Urban Heat Island on
the Global Structure of the ABL
CITES 2005, Novosibirsk
2D case: Computational domain
wind
0
5Z , km
45 55 120 X, km
urban heat island
Synoptic flow
CITES 2005, Novosibirsk
1.0
2.0
X, km
Z,k
m
40 60
0.5
1
1.5
2
2.5
0
UG=1 m/sat 1200 LST
Vertical section of horizontal wind speed (UG=1ms-1)
Vertical section of potential temperature and horizontal wind speed
UG=3 ms-1
UG=5 ms-1
( a ) ( b )
( c )
0.8
1.8
1.8
1.8
2.3
2.3
2.3 2.3
2.8
2.8
2.8
2.8
2.8
3.0
3.0
3.0
3.0
3.0
3.0
3.3
2.8
3.8
3.3
2.3
3.3
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=3ms-1
3.5
3.5
3.5
3.5
4.0
4.0
4.0
4.0
4.0
4.5
4.55
.0
5.05.0
5.5
6.06.0
6.5
7.07.0
7.57.5
8.08.0
8.58.5
4.5
4.5
6.5
5.5
3.5
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=3ms-1
3.5
3.0 3.0
3.0
3.0
3.5
3.5
3.5
3.5
4.0
4.0
4.5
4.5
4.5
4.5
5.0
5.05.0
5.55.5
6.06.06.56.5
7.07.07.0
7.57.58.08.0
8.58.5
4.0
4.0
4.5
3.5
3.54.0
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=5ms-1
1.82.1 2.12.4 2.42.7
2.73.0
3.0
3.3
3.3
3.3
3.6 3.6
3.63.9
3.9
3.9
3.94.2
4.2
4.24.5
4. 5
4.5
4.54.8
4.8
4.8
4.8
5.1
5.1
5.4
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=5ms-1
CITES 2005, Novosibirsk
Velocity vectors and isotachs of vertical speed at 12:00 LST
-0.1-0
.2
0.21. 0
0.50.7
-0.1
X ,km
Z,k
m
40 50 60
0.5
1
1.5
2
0
UG=3 ms-1
CITES 2005, Novosibirsk
Vertical section of potential temperature and horizontal wind speed
UG=3 ms-1
UG=5 ms-1
( a ) ( b )
( c )
0.8
1.8
1.8
1.8
2.3
2.3
2.3 2.3
2.8
2.8
2.8
2.8
2.8
3.0
3.0
3.0
3.0
3.0
3.0
3.3
2.8
3.8
3.3
2.3
3.3
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=3ms-1
3.5
3.5
3.5
3.5
4.0
4.0
4.0
4.0
4.0
4.5
4.55
.0
5.05.0
5.5
6.06.0
6.5
7.07.0
7.57.5
8.08.0
8.58.5
4.5
4.5
6.5
5.5
3.5
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=3ms-1
3.5
3.0 3.0
3.0
3.0
3.5
3.5
3.5
3.5
4.0
4.0
4.5
4.5
4.5
4.5
5.0
5.05.0
5.55.5
6.06.06.56.5
7.07.07.0
7.57.58.08.0
8.58.5
4.0
4.0
4.5
3.5
3.54.0
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=5ms-1
1.82.1 2.12.4 2.42.7
2.73.0
3.0
3.3
3.3
3.3
3.6 3.6
3.63.9
3.9
3.9
3.94.2
4.2
4.24.5
4. 5
4.5
4.54.8
4.8
4.8
4.8
5.1
5.1
5.4
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5UG=5ms-1
CITES 2005, Novosibirsk
Height of boundary layer
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5
32
1
0
1-UG =1m/sec
2-UG=3 m/sec
3-UG=5 m/sec
Height of boundary layerat 1200 LST
city
CITES 2005, Novosibirsk
Height of boundary layer
3.5
3.5 4.0
4.0
4.0
4.0
4.5
5.05.0
5.55.5
6.06.0
6.56.5
7.07.0
7.57.5
8.08.0
8.58.58.5
3.5
4.0
4.5
X (km)
z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
No longitudinal diffusion of heat
5.5
6.0
6.5
7.0
7.5
8.0
8.5
4.0
4.0
5.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
3.5
3.5
4.0
4.5
5.0
4.5
4.5
3.5
X (km)
Z(k
m)
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
With longitudinal diffusion of heat
wzz
Wx
Ut
x
<u
CITES 2005, Novosibirsk
Impact of the UHI and the UCL on the Mesoscale Flow
CITES 2005, Novosibirsk
Typical Flat Urban Modeling Domain
CITES 2005, Novosibirsk
Parameterization of Urban Roughness
wind
The concept of incorporation of urbancanopy model
( b )
wind
( a )
Scheme of the numerical grid in the urbanarea by Kondo et al. (1998)
Scheme of the numerical grid in the urbanarea by Martilli (2002)
CITES 2005, Novosibirsk
Governing Equations for UBL
2D case:0,x zU W
1,t x z zxU UU WU fwP Vu
uD
,t x zzV UV WV fUwv vD
0
21,t x z z z
W UW WW wP g
.t x z x zuU W w θD
CITES 2005, Novosibirsk
Turbulent fluxes
H c
∂Θ= +
∂K
zw θ -
M
∂U ∂V=- ,
∂z ∂zKuw , vw
M MK =E S H HK =E S
2 22 6 5
1 21 ( )
3 M HG s G gD
c is the countergradient term
2
20 1 2 3 4 5 6
11 1 ( )M H H HS s s G s s G s s s G g
D E
61
1 2 11
3H HS s GD c
2,HG N 2
,MG S
2 ,N gz
2 2
2 U VS
z z
2 21 2 3 4 5 61 M H M H H H M H HD d G d G d G G d G d G d G G G
1 2 3 1 2, ( 1,...,6) ( , , , , )i id s i arethe functionsof c c c c c
/E
CITES 2005, Novosibirsk
Three-parametric turbulence model
,,2μ E i i ii ii jj i+ (c /σ )(E /ε)E, , = Uu u u tE, ED
22( / )( / ) , , ˆ
E i ic EE tε, εD
0 1 2 3
2( )i iij
i ii
jj j
bu u
U E U
x x
2 2( / )( / ) , , 2 , 2 ,E i i iiE uc 2tθ ,
( , , , ) .iA U E are the extra terms in urban areas AD
CITES 2005, Novosibirsk
Parameterization of Effects of Urban Surfaces on the Airflow
[Raupach et al.(1991), Raupach (1992), Vu et al.(2002), Martilli (2002)]
The extra terms DA in the Governing Equations are:
DU = turbulent momentum flux (roofs and canyon floors) +
drag (vertical walls)
Dθ = turbulent fluxes of sensible heat from roofs and the canyon floor +
the temperature fluxes from the walls
DE = increasing of conversion of mean kinetic energy into the TKE
[ by as, for example, Raupach and Shaw (1982)]
a ‘second’ dissipation linked with the scale
of turbulence L=L(z) induced by the presence
of the buildings
pε 0.ˆ ( 7)c 1/2
ε pε
ED c
Lε
CITES 2005, Novosibirsk
Results of Simulation
CITES 2005, Novosibirsk
Vertical section of potential temperature and horizontal wind speed at 1200 LST
UG=3 ms-1
UG=5 ms-1
3.0
3.5
3.53.5
4.0
4.0
4.54.55.0
5.55.5
6.06.0
6.56.5
7.07.0
7.57.58.08.0
8.58.5
4.03.5
4.5
4.0
3.5
6.5
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5a)
0
3.0
3.0
3.5
4.0
4.0
4.0
4.5
4.54.5
5.05.05.55.5
6.06.06.56.5
7.07.0
7.57.57.5
8.08.0
8.58.5
3.5 3.53.0
3.0
5.0
6.5
6.0
8.5
4.0
4.0
3.0
3.5
5.0
3.5
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
c)
2.5
2.5
2.5
2.5
3.0
3.03
.0
3.0
3.0
3.0
3.5
3.5
3.5
3.5
4.0
3.0
2.01.5
2.0
3.0
2.5
4.0X,KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
b)
2.0 2.5
3.03.54.0
4.5
4.5
4.5
4.5
4.5
5.0
5.0 5.0
5.0
5.0
5.0
5.0
5.0
5.5
6.0
X,KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
d)
CITES 2005, Novosibirsk
Vector field of horizontal wind speed and isotachs of vertical velocity for 12:00 LST
0.2
0.2
0.6
0.8 -0
.2
-0.2
-0.3
X , KM
Z,K
M
40 50 60
0.5
1
1.5
2
2.5
UG=3ms-1
CITES 2005, Novosibirsk
Vector field of horizontal wind speed and isotachs for vertical velocity for 12:00 LST
-0.1
0
0.1
0
-0.07
0.1
5
0.1
3
-0.0
7
X, KM
Z,K
M
40 50 60
0.5
1
1.5
2
2.5
UG=5ms-1
CITES 2005, Novosibirsk
Vertical section of potential temperature and horizontal wind speed at 1200 LST
UG=3 ms-1
UG=5 ms-1
3.0
3.5
3.53.5
4.0
4.0
4.54.55.0
5.55.5
6.06.0
6.56.5
7.07.0
7.57.58.08.0
8.58.5
4.03.5
4.5
4.0
3.5
6.5
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5a)
0
3.0
3.0
3.5
4.0
4.0
4.0
4.5
4.54.5
5.05.05.55.5
6.06.06.56.5
7.07.0
7.57.57.5
8.08.0
8.58.5
3.5 3.53.0
3.0
5.0
6.5
6.0
8.5
4.0
4.0
3.0
3.5
5.0
3.5
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
c)
2.5
2.5
2.5
2.5
3.0
3.03
.0
3.0
3.0
3.0
3.5
3.5
3.5
3.5
4.0
3.0
2.01.5
2.0
3.0
2.5
4.0X,KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
b)
2.0 2.5
3.03.54.0
4.5
4.5
4.5
4.5
4.5
5.0
5.0 5.0
5.0
5.0
5.0
5.0
5.0
5.5
6.0
X,KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
d)
CITES 2005, Novosibirsk
Vertical section of potential temperature and horizontal wind speed(3 ms-1) for simulation at 1200 LST
Present computation
Computation
of Martilli
(JAM,2002,V.41,1
247-1266)
3.0
3.5
3.53.5
4.0
4.0
4.54.55.0
5.55.5
6.06.0
6.56.5
7.07.0
7.57.58.08.0
8.58.5
4.03.5
4.5
4.0
3.5
6.5
20 40 60 80 100 120
0.5
1
1.5
2
2.5a)
0
Z , km
km
2.5
2.5
2.5
2.5
3.0
3.03
.0
3.0
3.0
3.0
3.5
3.5
3.5
3.5
4.0
3.0
2.01.5
2.0
3.0
2.5
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
b)
Z , km
km
CITES 2005, Novosibirsk
Vertical section of potential temperature and
horizontal wind speed
UG=3 ms-1
UG=3 ms-1
2.5
2.5
2. 5
2.5
3.0
3. 0
3.0
3.0
3.0
3.0
3.5
3.5
3.5
3.5
3.5
3.5
4.0
4.0
3.0
1.5
2.54
.0
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
b)
1.3
1.3
1.3
1.8
1.8
1.8
2.3
2.3
2.3
2.8
2.8
2.8
2.8
2.8
2.8
3.3
3.3
3.3
3.33
.33
.33
.3
3.8
3.84.3
1.32.3
X,KM
Z,K
M
20 40 60 80 100 120
0.1
0.2
0.3
0.4
0.5
0
d)
4.04.5
5.0
5.0
5.55.55.0
4.5
3.5 3.54
.0
3.54.0
3.5
4.5
6.0 6.0
6.5 6.5
7.0 7.0
7.5 7.5
8.0 8.0
8.58.5
4.0
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
a)
12:00 LST
5.0
5.0
4.54.5
4.0 4.03.53.5
4.5
4.0
4.5
X, KM
Z,K
M
20 40 60 80 100 120
0.1
0.2
0.3
0.4
0.5
0
c)
24:00 LST
CITES 2005, Novosibirsk
Temperature field above the city
3.0 3.03.54.0
4.5
4.5
4.5
5.0
4.0
4.3
3.8
4.34.3
3.8
4.8
4.8
4.8
4.5
3.5
4.03.8
X, km
Z,k
m
20 40 60 80 100 120
0.1
0.2
0.3
0.4
0.5
0
UG=3ms-1 24:00 LST
Temperature field avove the city
CITES 2005, Novosibirsk
The Vertical Temperature Profiles
Temperature, 0K
Z,k
m
2 3 4 5 6 70
0.1
0.2
0.3
1200 LST
2400LST1200LST
2400LST
blue lines are at the city centerred lines are out the city
CITES 2005, Novosibirsk
Vertical section of potential temperature and
horizontal wind speed
UG=3 ms-1
UG=3 ms-1
2.5
2.5
2. 5
2.5
3.0
3. 0
3.0
3.0
3.0
3.0
3.5
3.5
3.5
3.5
3.5
3.5
4.0
4.0
3.0
1.5
2.54
.0
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
b)
1.3
1.3
1.3
1.8
1.8
1.8
2.3
2.3
2.3
2.8
2.8
2.8
2.8
2.8
2.8
3.3
3.3
3.3
3.33
.33
.33
.3
3.8
3.84.3
1.32.3
X,KM
Z,K
M
20 40 60 80 100 120
0.1
0.2
0.3
0.4
0.5
0
d)
4.04.5
5.0
5.0
5.55.55.0
4.5
3.5 3.54
.0
3.54.0
3.5
4.5
6.0 6.0
6.5 6.5
7.0 7.0
7.5 7.5
8.0 8.0
8.58.5
4.0
X, KM
Z,K
M
20 40 60 80 100 120
0.5
1
1.5
2
2.5
0
a)
12:00 LST
5.0
5.0
4.54.5
4.0 4.03.53.5
4.5
4.0
4.5
X, KM
Z,K
M
20 40 60 80 100 120
0.1
0.2
0.3
0.4
0.5
0
c)
24:00 LST
CITES 2005, Novosibirsk
Vertical profiles of ‘local’ friction velocity
u* / u*max
Z/Z
H
-1 0 1 2 30
1
2
3
4
5
6
7
1 2
Rotach M.
Oikawa and Meng
Feigenwinter C.
UG=3 ms-1
UG=5 ms-1
Real scale data
Computation
1/ 42 2
*u uw vw
CITES 2005, Novosibirsk
Verticals profiles of ratio u*/U
u* / U
Z/Z
H
0 0.05 0.1 0.15 0.2 0.25 0.3 0.350
1
2
3
4
5
6
7
1 2
Real scale datafrom Roth (2000)
Computation:UG=3ms
-1
UG=5ms-1
CITES 2005, Novosibirsk
Vertical profiles of TKE in the centre city
+ ++
++
E / (u* max)2
Z/Z
H
0 1 2 3 4 5 6 7 80
1
2
3
4
5
+
1
4
2
3
UG=3ms-1
UG=5ms-1
Rotach(1993)
Oikawa, Meng(1995)
Feigenwinter (1999)
Louka et al.(2000)
Computation:1,3 - at 1200 LST2,4 - at 2400 LST
Observations data:
CITES 2005, Novosibirsk
Turbulent kinetic energy, 2 -2m s
0.39
0.39
0.39
1.16 1.16
1.16
1.16
1.16
1.931.93
1.93
1.93
1.93
1.93
2.7
1
2.71
2.71
2.71
3.48
3.48
3.4
8
4.2
5
4.25
4.25
5.03
5.03
5.03
5.80
X, km
Z,k
m
20 40 60 80 100 120
0.5
1
1.5
2
2.5
UG=3ms-1
12:00 LST
CITES 2005, Novosibirsk
0.2
0.2
0.6
0.8 -0
.2
-0.2
-0. 3
X , KM
Z,K
M
40 50 60 70 80 90 100
0.5
1
1.5
2
2.5
UG=3ms-1
CITES 2005, Novosibirsk
CONCLUSIONS■ Using the updated expressions for the pressure-velocity
and pressure-temperature correlations, we have derived an improved turbulence model to describe the Urban Boundary Layer.
■ In simple 2D case are investigated the modifications in global structure of the ABL caused by the Urban Heat Island and the Urban Canopy Layer.
■ The comparison between computed results and field observational data on various integrated turbulent characteristics reveals that the improved model can simulate the turbulent transport processes within and above the building canopy with satisfactory accuracy.