Terrain-Induce Turbulence Prediction for Aviation Safety

Motivation Methodology Real application: Forecasting Special Analysis: Alta Airport

Terrain Induced Turbulence Prediction for Aviation Safety

Adil RASHEED, Karstein SØrli

Applied Mathematics
SINTEF ICT

adil.rasheed@sintef.no

June 29, 2010

Adil RASHEED, Karstein SØrli SINTEF ICT Applied Mathematics


Outline

1 Motivation

2 Methodology
Theory

3 Real application: Forecasting
Nesting
Validation

4 Special Analysis: Alta Airport
Haugesund Airport
Kristiansund Airport
Alta Airport



Incidents and accidents

On 11 March 1982, Widerøe Flight 933, operated by the Twin Otter LN-BNK
˚
crashed into the Barents Sea near Gamvik, on route from Berlevag Airport to
Mehamn Airport. All investigations have concluded that the crash resulted from
structural failure of the aircraft’s tail caused by severe clear-air turbulence.
On 12 April 1990, Widerøe Flight 839, operated by a Twin Otter, crashed into the
seas one minute after take-off from Værøy Airport, killing all ﬁve on board. The
cause of the crash had been strong and unpredictable wind gusts during take-off,
which had exceeded the plane’s limits and created a break-up in the plane’s tail
rudder, so the plane became uncontrollable.



Hammerfest Airport: 1 May 2005

On 1 May 2005, the Widerøe Dash-8-100 airplane LN-WIK was buffeted by strong
winds upon landing, and the landing gear on the right wing collapsed. While several
passengers sustained injuries, there were no fatalities in the incident, but the
Norwegian Civil Aviation Authority imposed the strictest wind regulations in Norway
upon the airport.



Amsterdam, Geneva, Paris, Frankfurt

Flat terrain



Norwegian airports

Characterized by fjords, hills, mountains, valleys resulting in rotors, mountain waves
etc. ...


Theory

Governing Equations

· (ρs u) = 0 (1)

Du pd θd 1
=− +g + ·R+f (2)
Dt ρs θs ρs
Dθ
= · (γT θ) + q (3)
Dt
DK
= · (νT K ) + Pk + Gθ − (4)
Dt

D νT 2
= · + (C1 Pk + C3 Gθ ) − C2 (5)
Dt σe k k
SIMRA: Semi IMplicit Reynolds Averaged
Structured version for forecasting
Unstructured version for special analysis



Theory

Boundary Conditions (for special analysis)

4000

3000

u∗ z z

z(m)
2000
u0 (z) = ln +W (6)
κ z0 D
−1/2 2 z 1000
K (z) = Cµ u∗ 1− (7)
D
0
270 275 280 285 290
potential temperature (K)

Potential temperature proﬁle for Stable
Stratiﬁcation

For forecasting: Nesting with Bigger scale model (UM1)



Theory

Terrain induced shear

du
dx

du

dz

1
L= C ρ (|U
2 L inf
− Vp |)2



Theory

Effect of horizontal and vertical shear

Horizontal shear Vertical shear



Theory

Safety Analysis

f
c ∂u w c w f
F =− + =− [u(x + f /2 − u(x − f /2)t] + (8)
g ∂x c g f c

1/2 1/3
1/3 (Cµ K )3/2 −1/3
≈ ≈ 0.67K 1/2 t (9)
t

c is the fly path, g gravitational acceleration u is the wind component along the fly path,
w vertical wind component, turbulent dissipation, K turbulent kinetic energy t
turbulent length scale f minimum response distance for landing configuration and is of
the order of ∼ 500 m, Prevalence of the two conditions F < −0.1 and
1/3 > 0.5 m2/3 s −1 correnspond to severe turbulence for commercial aircrafts and
√
represent potential danger. These conditions are easily met when K > 3 ms−1 .



Nesting

Nesting: HIRLAM12− > HIRLAM8− > UM4− > UM1− > SIMRA



Validation

Brønnøysund



Validation

Evenes



Validation

Fordes



Validation

Hammerfast



Validation

˚
Honnigsvag



Validation

Mosjøen



Validation

Ørsta-Volda



Validation

Narvik



Validation

Sandane



Validation

Værnes



Validation

Right tool for the right job

So ... Downscaling does not always work. Use an appropriate model to resolve
interesting scales


Haugesund Airport

Haugesund Airport



Haugesund Airport

Special Analysis: Haugesund airport

Located on the west side of the island
and municipality of Karmøy, southwest
of Haugesund.
Operated by Avinor since 1975
Scandinavian Airlines, Norwegian Air
Shuttle.
Runway dimension: 2120 m × 45 m.
Elevation of 86 m above mean sea
level
The airport had 514, 947 passengers
in 2007



Haugesund Airport

Haugesund: Windrose

Spring Autumn

Summer Winter
The airport is not bothered by intense turbulence. Uneven side wind from the SSW and
sometimes from the north, with strength 13m/s or more, can provide turbulent
conditions on the ﬁnal


Haugesund Airport

Haugesund: Terrain and Mesh

Terrain in the vicinity of the Haugesund 300 × 300 times 40 mesh
airport



Haugesund Airport
√
K = 3 contours for free stream velocity of 30 m/s

No potential
danger.
α = 60o α = 90o Turbulent zones
are located far
away from the
airport.

α = 120o α = 150o



Haugesund Airport
√
K contour along the ﬂy path

α = 60o α = 90o

α = 120o α = 150o


Haugesund Airport
√
Haugesund: K contours and velocity ﬁeld projected on the cone
containing the gliding path for a free stream velocity of 20 m/s

α = 60o α = 120o

α = 90o
Adil RASHEED, Karstein SØrli
α = 150o SINTEF ICT Applied Mathematics



Kristiansand Airport

Braathens SAFE Boeing after landing accident 1977-10-31



Sample Application: Kristiansand Airport (Kjevik)

Situated 4.3 NM (8.0 km) north-east of
the city Kristiansand, Vest-Agder in
southern Norway
The airport serves the Agder district
with domestic and international ﬂights.
The airport is operated by Avinor.
Surrounded by water on three sides
and hills on the fourth
Vigorous turbulence is experienced for
Northwesterly wind




Kjevik: Mesh and Terrain

β

β is the gliding angle
300 × 300 × 40 mesh
Resolution: 50 − 200 m
Domain size:30 km × 30 km × 3 km




Turbulent Kinetic Energy along the surface of the cone




3-D Velocity Field for α = 240o

Flow channelizes through the valleys



3-D Velocity Field for α = 320o

Flow ascends up the mountain


√
3-D K contours for α = 320o



√
3-D K contours for α = 320o

These plots are for free stream velocity of 20 m/s
√
K scales with this velocity


Alta Airport

Alta



Alta Airport

Special Analysis: Alta airport

Situated 4km northeast of the town
center of Alta on a plain where Alta
River ﬂows in the fjord
2, 088 m long runway
Operated by Avinor.
334, 132 passengers served in 2009
(busiest in Finnmark)
Provision for wind and turbulence
measurement on Komsa hill (200m)
SAS, Norwegian



Alta Airport

Alta: Terrain

For 20 − 25m/s wind speed strong turbulence is experienced. Wind from SSW to NW
is most problematic.



Alta Airport

Alta: Windrose

Spring Autumn

Winter
Summer



Alta Airport

Alta: Terrain and Mesh

Terrain in the vicinity of Alta airport and
gliding plane

300 × 300 times 40 mesh



Alta Airport

Turbulent Kinetic Energy along the surface of the cone

Severe
α = 60o α = 90o turbulence for
α = 60o and
α = 90o

α = 120o
Adil RASHEED, Karstein SØrli α = 300o SINTEF ICT Applied Mathematics


Alta Airport

Turbulent Kinetic Energy along the ﬂy path

Severe
α = 60o α = 90o turbulence for
α = 60o and
α = 90o

α = 120o α = 300o


Alta Airport
√
Alta: K = 3 contours for free stream wind speed of 30m/s

α = 60o α = 120o

α = 90o α = 300o


Alta Airport

Alta: Effects of Stratiﬁcation

Ua = 10m/s, Fr = 1.0 Ua = 18m/s, Fr = 1.8

Ua = 15m/s, Fr = 1.5 Ua = 20m/s, Fr = 2.0


Alta Airport

Alta: Effects of Stratiﬁcation and Komsa hill

Ua = 10m/s, Fr = 1.0 Ua = 15m/s, Fr = 1.5



Alta Airport

Thank you

Do not be afraid: WECOME to Norway :)


Terrain-Induce Turbulence Prediction for Aviation Safety

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Ähnlich wie Terrain-Induce Turbulence Prediction for Aviation Safety

Ähnlich wie Terrain-Induce Turbulence Prediction for Aviation Safety (15)

Mehr von epfl

Mehr von epfl (7)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

Terrain-Induce Turbulence Prediction for Aviation Safety