Ansys Software Helps Ferrari Improve Comfort

Italian car manufacturer Ferrari is using software from Ansys to optimise automobile design and performance. Ferrari is using software from Ansys to predict thermal comfort in a vehicle's interior. In order to assess comfort qualitatively and quantitatively, the car manufacturer worked with Pisa University in Italy to define thermal comfort indices and to evaluate the general aspects of thermal comfort.

Since an experimental approach was not practical, the investigating engineering team used fluid dynamics software from Ansys to perform the calculations. According to Giovanni Lombardi, professor of aeroplane aerodynamics and vehicle aerodynamics at Pisa University, the Ansys engineering simulation software rendered accurate and reliable results.

The research team based its resulting 'global thermal comfort index' on several local indices: the thermal equilibrium of the human body, discomfort caused by drafts and horizontal and vertical temperature gradients. Various factors were studied, including the car's velocity and materials (leather, glass and aluminium) as well as sensitivity to warming or cooling on various body sites (leg, arm and face, covered with clothing or not), solar irradiance, vehicle interior size and air flow.

'The advantage of simulation-driven product development is that no complex physical models or testing configurations are required and the design can be tested, optimised and, if necessary, modified virtually at an early stage in the development process,' said Jim Cashman, president and chief executive of Ansys.

Pam-Comfort Helps Renault Design New Seat

Renault has used ESI's Pam-Comfort system for the preliminary design of a new seat. ESI's Pam-Comfort software offers a scalable and customised solution dedicated to virtual manufacturing and virtual testing (static and dynamic) of the soft parts of a seat. Virtual seat prototyping consists of several chained simulated steps ranging from seat manufacturing and occupant static seating, to occupied seat NVH (noise and vibration), where the stresses resulting from each step are needed for the next one.

The chaining is necessary to accurately predict the behaviour of the seats under numerous loading conditions (trimming, dummy loading, various human anthropometries and vibrations) and for various design changes (materials and shape). At Renault, where the full virtual seat prototyping methodology is being deployed, an important step after the preliminary design of a new seat is the virtual testing of the dynamic comfort performance using Pam-Comfort.

To accurately predict seat comfort, Renault runs a dynamic test of seat transmissibility with a static weight. The test helps evaluate the seat frequency response and thus informs Renault about how the seat contributes to the vertical acceleration filtering of the car, which is important for dynamic seat comfort. This test is used to improve and validate the seat design. Renault simulated this test procedure with a finite element calculation using Pam-Comfort. After completing the seat-manufacturing simulations, a dummy is imported in the model to launch the computation.

This calculation is divided in two phases: first, a static phase in which the dummy is seated and where the equilibrium is computed to precisely know the stress and strain states of the various parts of the seat; second is a dynamic phase in which a vertical acceleration signal is applied to the seat rail to obtain the seat dynamic transmissibility at the interface with the dummy. Computed results showed a good level of correlation with physical tests, therefore confirming the validity and predictability of both Renault's simulation modelling and the methodology applied.