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Tall buildingswind engineering & architectural aerodynamics
London | Hong Kong | Kuala Lumpur | Abu Dhabi | Dubai | Shanghai | Houston
tall and supertall buildings due to their overall scale and increasing complexity in architectural shape and sophistication are highly wind sensitive
structures in terms of their technical feasibility and cost effectiveness.
Tel: +44 20 8614 4400 Fax: +44 20 8943 3224 Email: [email protected] Website: www.bmtfm.com
sustainable design approaches are dictating design
solutions for tall buildings that are energy efficient
and efficient in their consumption of building material.
For sustainable, cost efficient, and safe design these
structures now commonly require specialist wind studies
to provide design guidance from concept to final design
stages and beyond, to provide on-site performance
validation of key building parameters.
where required, generic wind models are complemented
through detailed modelling of non-synoptic wind patterns
using approaches such as topography modelling and
mesoscale models. wind climate studies are accepted
throughout the world by local building departments and
regulatory bodies and deliver a robust basis for reduction
of inherent conservatism in design codes.
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 long-
term 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.
Bmt Fluid mechanics (Bmt) operates a highly specialised
and resourceful tall building group that provides designers
with a comprehensive portfolio of consultancy services
for structural, serviceability and environmental design
based on substantial in-house capabilities and experience
for boundary layer wind tunnel testing and numerical
modelling.
Key services
• wind climate analysis
• structural load analysis
• Building motion / dynamic response analysis
• auxiliary damping system configuration
• Pedestrian wind comfort analysis / environmental impact assessment
• Façade pressure analysis (wind and blast)
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 for blast scenarios
Wind Climate analysis Cont
Wind Climate analysis
Design Wind Speeds Wind Frequency Data
Non-synoptic Wind Profile Synoptic Wind Profile
Mesoscale Model
Hurricane noaa/sCienCe PHoto liBRaRy
the design requirement to constrain wind-induced
building sway to levels that are acceptable from an
occupant comfort point is often the driving criterion in the
design of the lateral stability systems of tall and super
tall buildings. high frequency force balance and high
frequency pressure integration testing techniques can
deliver accurate quantification of peak building sway and
provide an assessment of acceptability relative to industry
standard comfort criteria.
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 aeroelastic
modelling may be employed to validate the performance
of these damping systems.
dynamiC ResPonse / Building motion analysis
FaCade PRessuRe analysis
Peak Acceleration Criteria Peak Accelerations
Block Zone Diagram
For simple geometries that are exposed to wind in isolated conditions it is often
possible to derive safe design wind loading for façade systems by application of
code methodology, which is limited to rather simple shapes. however, in most
practical applications strong aerodynamic interference effects from adjacent
buildings and architecturally complex external shapes, application of code
methodology often leads to highly conservative estimates of wind pressures.
using wind tunnel testing technology, cladding pressures on glazed facades
and façade features such as clad parapet walls and canopies can be accurately
measured using detailed small-scale wind tunnel models instrumented with a
large number of pressure taps. internal pressures including stack effects can be
quantified using computational internal air flow models.
dynamic wind loading is a governing parameter in the
design of the foundations and the superstructure of tall
buildings. 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) and high frequency
pressure integration (hFPi) techniques allow accurate
determination of critical loading scenarios accounting
for the structural stiffness of the building and structural
coupling of multiple tower arrangements.
Bmt operates state-of-the-art multiple simultaneous
dynamic force balance systems, as well as a custom built
1152 channel simultaneous low-range pressure scanning
system, that allow complex geometries and linked towers
to be comprehensively studied.
Bmt are able to interactively 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 for all design
arrangements. it has become increasingly common to
apply these technologies in ‘wind loading workshops’, in
which the geometry can be varied and instantaneously
analysed, giving best value to the design team. web-
coupled digital video monitoring and data presentation
systems allow remote client interaction removing the
need for travel to the test facility. 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.
stRuCtuRal load analysis
High Frequency Force Balance Model
Force Spectra Dynamic Base Loads
Pressure ModelFlow Visualisation
Tel: +44 20 8614 4400 Fax: +44 20 8943 3224 Email: [email protected] Website: www.bmtfm.com
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 structures
are commensurate with formats required by planning
authorities for environmental impact assessments (eia).
PedestRian Wind ComFoRt analysis Cont
sophisticated 3d contouring software allowing automated
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 design by façade contractors.
international building regulations in some cases require
designers to design building facades and key structural
support elements to withstand bomb blasts. a number of
codified engineering methods exist to assist designers in
this task, though, these are rather simplified. to support
performance based design approaches through more
sophisticated numerical modelling of blast impact
on building facades, Bmt has developed in-house
capabilities for blast modelling than can be applied
to complex building arrangements to derive accurate
dynamic loading and consequence scenarios.
FaCade PRessuRe analysis Cont
Cladding Pressure Contours
Wind Mitigation Scheme
Downdraft
Comfort & Safety Rating For Pedestrian Wind Environment Suitability Criteria
generating controlled external microclimate in the vicinity
of tall buildings by purposeful development of wind
mitigation schemes that protect from the unfavourable
action of downdrafts and ground-level wind funnelling is
key to the commercial success of external recreational
spaces and key to ensuring user comfort.
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,
including balconies and roof terraces, and for pedestrian
wind comfort to be defined in terms of suitability for
planned uses.
PedestRian Wind ComFoRt analysis
Tel: +44 20 8614 4400 Fax: +44 20 8943 3224 Email: [email protected] Website: www.bmtfm.com
For further information contact: Tel: +44 20 8614 4400 Fax: +44 20 8943 3224Email: [email protected] Website: www.bmtfm.com
BMT Fluid Mechanics Limited, 67 Stanton Avenue, Teddington, Middlesex, TW11 0JY, UK