Consultancy : Aerodynamics

The Importance of Aerodynamics

Aerodynamics should not be underestimated in the overall vehicle development process as it influences, or controls a wide range of key vehicle characteristics, including:

• Maximum vehicle speed and acceleration
• Vehicle stability particularly at high speeds or in crosswinds
• Wind noise levels
• Vehicle range
• Fuel consumption
• Emissions output
• Powertrain cooling and heat exchanger performance
• Brake cooling
• Vehicle soiling
• Occupant comfort; heating, ventilation, air-conditioning (HVAC) performance
• Occupant comfort in open top vehicles

Integrating Aerodynamics into a Vehicle Programme

MIRA's approach to vehicle aerodynamic development is designed deliver improved product quality by highlighting and removing potential risks, endeavouring to eliminate rework costs and drive down lead times.  Our strategy involves:

• Early evaluation of designs working with the stylist.  We employ Computational Fluid Dynamics (CFD) and wind tunnel testing (model or full scale) to analyse vehicle aerodynamics and illuminate areas of potential risk.
• Use of proven analysis tools and methods.
• Rigorous target setting based on experience, analysis, testing and benchmarking of competitor products.
• Using appropriate techniques to improve accuracy such as advanced CFD methods to predict wind noise or to simulate a moving ground plane.
• Providing aerodynamic data to support related engineering project teams such as powertrain, chassis, NVH and HVAC / climate control.
• Using co-simulation techniques to support powertrain cooling and climate control systems integration.

The following sections describe how we consider the interactions between a vehicle's aerodynamic characteristics with other key attributes.

Vehicle Stability

Vehicle stability issues can influence subtle handling characteristics of a racecar through to major safety considerations for a fully-loaded 38-tonne truck. Both very different issues, but equally crucial for their respective operators. MIRA’s in-house virtual modeling processes integrate aerodynamic and vehicle handling inputs to assess their combined effects on vehicle control. Such techniques are used alongside wind tunnel and proving-ground testing to offer a total solution for vehicle stability engineering.

Aero-Acoustics

Aero-acoustics is a key issue when it comes to perceived levels of refinement and comfort in a vehicle. Higher expectations from customers are driving this specialist area. MIRA uses several techniques – both computer based and within test facilities – to reduce the acoustic effects caused by wind noise around the vehicle. This ultimately creates enhanced occupant comfort and customer satisfaction.

Water Management

The influence of styling over such aspects of a vehicle's design as guttering and guides to manage rain water has passed much of the responsibility for water management to the aerodynamicist.  MIRA's aerodynamicists employ subtle changes to windscreen and A-pillar design along with aerodynamically and visually unobtrusive gutters to improve visibility and eliminate potential sources of customer annoyance.

In inclement weather visibility is affected by the vehicle shape and the flow of air around the vehicle.  MIRA's aerodynamicists endeavour to maintain forward and rearward visibility and also to allow clear views of the exterior mirrors.

Wiper loads and consequently their performance are influenced by the aerodynamically induced loads they are subjected to.  MIRA's aerodynamicists have worked on projects for both wiper OEMs and vehicle manufacturers to optimise wiper designs.

Soiling

Soiling is prone to occur in regions of separation and poor airflow.  For this reason we pay particular attention to areas around doors and boot openings as dirt accumulation in theses areas can lead to customer annoyance.

Cooling

Through selective combinations of CFD modeling and physical testing we assess vehicle design and packaging to optimise airflows for powertrain and brake cooling performance.

Non-Automotive Applications

MIRA’s aerodynamics expertise is frequently called upon for a diverse selection of non-automotive products. From other forms of transport such as trains and bicycles through to totally unrelated products... Lifeboats, aerials, wheely bins, tents, sports clothing and even world class skiers! All have benefited from our aerodynamics expertise and development facilities.

Further details of MIRA's unique approach to vehicle aerodynamics development is discussed here:

vAEROsim™ vehicle aerodynamics simulation process

Training Courses and Aerodynamics Conference

Aerodynamics training courses are held throughout the year to allow others to benefit from our knowledge and experience. Courses combine‘classroom’ theory with practical sessions in our wind tunnels, as well as looking at advanced virtual techniques such as Computational Fluid Dynamics (CFD). MIRA also organises an international vehicle aerodynamics conference every two years which attracts the cream of the world’s aerodynamicists.

Complementary Services and Facilities

Aerodynamic consultancy is part of MIRA's comprehensive capabilities for aerodynamics, fluid dynamics and thermal management.  Further details of which can be found using the following links:

Aerodynamics Testing

Thermal Management Consultancy

Thermal Management Testing

Climatic Wind Tunnel – CWTone
Climatic Wind Tunnel – CWTtwo
Fluid Systems Engineering Centre
Full Scale Aerodynamic Wind Tunnel
Model Scale Aerodynamic Wind Tunnel
Computational Fluid Dynamics (CFD) suite
Extensive Proving Ground test circuits