Numerical models of ski jumps

Many out door activities are affected by local wind conditions. Ski jumping is a typical example of a wind affected activity. In many situations it would be desirable to reduce to wind loads in order to have equal and safe conditions within ski jumping.

Accurate knowledge about the local wind conditions is determined in a numerical model. If the wind conditions are known it will be possible to:

Determine the wind loads

Reduce the wind loads by constructional arrangements

Reduce the wind loads by choosing an optimal time window for the activity

A numerical model of a ski jump has several application areas. Obviously, during design or redesign of a ski jump the influence from infrastructure must be determined. Erection of wind sails must be considered carefully for optimal position and porosity.

Further, a numerical model could be used during competitions. Typically a wind measurement system gives wind speed information in a single point. In combination with a numerical model the measurement is extended to cover the whole ski jump. Judgements about safe jumping conditions should be based on this extended information about the wind conditions.

Demonstration case - Holmenkollen

In order to demonstrate the software, a numerical model of the Holmenkollen ski jump in Oslo have been established. In Holmenkollen some facilities for erecting a wind sail have been constructed. As this is merely a demonstration of the software no attempt to represent accurately the actual wind sail in Holmenkollen is done. Three simulations are carried out with wind from north-north-west, same positioning of the wind sail but with different porosity, which is the ability of the sail to let the wind flow through.

Actual optimisation of a wind sail position and its porosity will demand a larger amount of simulations with various wind directions and wind sail configurations.