wind engineering & architectural aerodynamics

London | Hong Kong | Kuala Lumpur | Abu Dhabi | Dubai | Shanghai

London | Hong Kong | Kuala Lumpur | Abu Dhabi | Dubai | Shanghai | Houston

with the globally increasing volume in air traffic, airport passenger

terminal buildings (PtB) are being designed at unprecedented scale and

increasingly employing landmark architecture and innovative structural

design of support systems for the roof.

cost effective design of these structures - often of unusual

external envelope - is dictating light-weight design,

making these roof structures highly sensitive to driving live

loading such as wind and accumulated snow or sand. in

order for sophisticate 3d structural modelling to deliver

efficient structural design accurate loading scenarios are

required for wind that account for complex fluid structure

interactions including wind driven dynamic effects. arrival

and departure areas are also sensitive to pedestrian wind

comfort and the quality of the external microclimate in

these areas requires careful consideration from an early

stage in design.

wind induced dynamic loading and sway of air traffic

control towers (atct) is not very reliably predicted by

codified methodology and can often be strongly affected

by unsteady vortex flow phenomena, which can cause

highly dynamic behaviour. air traffic controller comfort

with respect to wind-induced sway of the atct is an

imperative design requirement and requires specialist

wind studies.

Key services

wind climate analysis

• structural load analysis for PtB and atct

• Building motion / dynamic response analysis for atct

• auxiliary damping system configuration for atct

• Pedestrian wind comfort analysis / environmental

impact assessment

• Façade pressure analysis (wind and blast) for PtB

the safety and operability of airports and heliports can be

influenced by turbulence and wind shear, and by proximity

to sources of hot gases as power stations. turbulence

and wind shear is caused primarily by the local natural

topography such as mountainous or hilly terrain and

by proximity to the PtB and large aircraft hangers. the

disruption to the natural wind flows can have a serious

effect on the performance and controllability of fixed wing

aircraft and helicopters, and can result in operational

restrictions being placed on the airport or heliport under

certain wind conditions. the presence of hot gases is

also a potential hazard because increases in ambient air

temperature reduce both lift and engine power. this is a

particular issue for operations in close proximity to power

generation equipment. these aerodynamic effects can be

studied at the design concept stage, and the results used

by aircraft operators and pilots to maximise the safe and

efficient operation of the airport or heliport.

Key BeneFits

cost effective structural design

cost effective façade design

optimised occupant comfort

external microclimate control

interactive solution development

iterative design optimisation

efficient and safe design against terrorist threat

Wind Climate analysis

the specification of design wind speeds for structural,

serviceability and environmental design requires careful

analysis of long-term wind statistics. Bmt has access

to global wind record databases, which provide longterm

wind statistics for extreme wind events including

synoptic and non-synoptic wind patterns including

e.g. typhoon, shamal, thunderstorm and monsoon

winds. By application of sophisticated industry-standard

wind models of the atmospheric boundary layer and

extreme value statistical analysis of storm records,

site-specific wind climate models are generated for each

development that can also provide detailed resolution

of wind directionality and probability of occurrence.

where required, generic wind models are complemented

through detailed modelling of non-synoptic wind patterns

Non-synoptic Wind Profile Synoptic Wind Profile

Design Wind Speeds Wind Frequency Data

using approaches such as topography modelling and

mesoscale models. wind climate studies are accepted

throughout the world by local building departments and

regulatory bodies as a basis of design and deliver a

robust basis for reduction of inherent conservatism in

code design winds.

Hurricane nOaa/sCienCe PHOtO liBRaRy

Tel: +44 20 8614 4400 Fax: +44 20 8943 3224 Email: Website:

dynamiC Wind lOading analysis fOR PtB ROOf stRuCtuRe design

dynamic wind loading is in many cases a governing parameter in the design

of the primary and secondary structural support systems of the roof of the

PtB. cost efficient design of these components requires reliable quantification

of these loading factors. Boundary layer wind tunnel testing based on high

frequency pressure integration (hFPi) techniques allow accurate determination

of critical loading scenarios accounting for the structural stiffness of the roof. in

particular, this technique allows detailed analysis of structural load effects such

as net uplift / downforce and vertical shear cases based on structural influence

lines thereby delivering loading scenarios for structural design which are

substantially less conservative than applicable codes of practice.

Bmt operates state of the art custom-built 1152 channel simultaneous lowrange

pressure scanning system that allows unsteady external pressure fields

to be measured to a high degree of spatial resolution. wind tunnel data can be

reanalysed iteratively for different structural parameters such as stiffness and

damping as the design evolves eliminating the need for repeat testing allowing

for efficient tuning of the structural system.

dynamiC ResPOnse analysis fOR atCt design

dynamic wind loading is a governing parameter in

the design of the foundations and the superstructure

of atct structures. cost efficient design of these

components requires reliable quantification of these wind

parameters. Boundary layer wind tunnel testing based

on high frequency force balance (hFFB) techniques

allow accurate determination of critical loading scenarios

accounting for the structural stiffness of the atct. Bmt

are able to employ force balance testing technology

coupled to sophisticated on-line data analysis software,

which allows designers at an early stage in the design

to interactively and cost effectively support architectural

form finding and structural concept studies through

accurate wind loading analysis. wind tunnel data can be

reanalysed iteratively for different structural parameters as

the design evolves eliminating the need for repeat testing

allowing for efficient tuning of the structural system.

ATCT Wind Tunnel Model

PTB Pressure Model

Pressure Distribution for Structural Design

dynamiC ResPOnse analysis

fOR atCt design COnt

the requirement to constrain wind induced building sway

to perceptible levels that are acceptable from an air traffic

controller comfort perspective often drives the design

of the lateral stability systems of the atct, particularly

because vortex induced vibration (viv) can be highly

significant for these type of structures.

hFFB testing techniques can deliver accurate

quantification of peak sway and provide an assessment

of acceptability relative to industry standard comfort

criteria for atct structures. these analysis techniques

allow iteration between key performance parameters of

the structural system such as building stiffness, mass and

damping and dynamic wind responses to progressively

derive the optimum configuration. in cases where auxiliary

damping systems are required to limit building sway full

aerolastic modelling techniques may be employed to

validate the performance of these damping systems.

Acceleration Criteria

Cladding PRessuRe analysis fOR façade design

cladding pressures on glazed facades and roof-cladding systems can

be accurately measured using detailed small-scale wind tunnel models

Vortex Shedding Spectra

instrumented with pressure taps. internal pressures can be quantified using

computational internal airflow models. sophisticated 3d contouring software

providing animated on-line presentation of surface pressure data for complex

external building form allows the façade pressures to be effectively displayed

in a way that is easily digested into cost effective façade/cladding system

design by façade contractors.

ATCT Pressure Model Pressure Contours Pressure Contours

Tel: +44 20 8614 4400 Fax: +44 20 8943 3224 Email: Website:

PedestRian COmfORt analysis fOR PtB design

generating controlled external and internal microclimate

by purposeful development of wind mitigation schemes

that protect from the unfavourable action of downdrafts

and ground level wind funnelling is key to the useability of

the external spaces in the pedestrian arrival and departure

zones of PtB. Bmt operates multiple channel wind speed

sensing systems that allow the wind speed up to be

quantified in severity and spatial extent in key pedestrian

areas and for pedestrian wind comfort to be assessed.

Bmt’s interactive approach to pedestrian wind comfort

studies allows designers to develop wind mitigation

schemes and validate these for effectiveness through time

and cost-efficient iterative wind tunnel test workshop days.

Bmt’s technical and interpretative reporting is compatible

with environmental impact assessment formats required

by planning authorities.

Pedestrian Comfort Assessment

Wind dRiven snOW & sand dRift / aCCumulatiOn analysis fOR

PtB ROOf stRuCtuRe design

depending on local climate, wind driven sand or snow accumulation and

drift can cause significant loading on the large span roof structures of a PtB.

codified methodology available to designers is often rather simplistic and

when applied to complex roof arrangements can lead to overly conservative

structural design solutions.

Bmt have purposely developed number of sophisticated physical and

numerical modelling techniques including aeolian transport and particle

tracking models to provide designers with the opportunity to study the effects

in greater detail and to derive more bespoke quantification of key loading


CFD Simulation

Sand Drift

analysis Of Building Wake imPaCt On aiRCRaft OPeRatiOns

the analysis of wind shear and turbulence over airport

runways that can arise due to unsteady wakes emanating

from PtB or aircraft hangars can be reliably quantified

through model scale boundary layer testing using hot-wire

equipment, which can scan wind conditions on aircraft

approach paths. these measurements can be combined

with long-term wind statistics for the site to define the

significance of potentially critical impacts on aircraft


in this type of assessment it is critical to take dues

cognisance of aircraft type and size because this controls

the band of turbulence length scales that determine

impact aircraft response. Bmt has been involved in

research including review of reported bad landing

conditions. this has led to a good understanding of the

turbulence criteria that govern large passenger aircraft

response during landing to turbulence and wind shear,

which can be applied in project specific studies.

Montserrat Airstrip

Tel: +44 20 8614 4400 Fax: +44 20 8943 3224 Email: Website:

Site Layout

Turbulence Specra

Wind Tunnel Model

For further information contact:

Tel: +44 20 8614 4400 Fax: +44 20 8943 3224

Email: Website:

BMT Fluid Mechanics Limited, 67 Stanton Avenue, Teddington, Middlesex, TW11 0JY, UK

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