TNO Webapplications
Cp Info
Back to TNO

Cp Info

'Cp Generator' predicts the dimensionless static wind pressure coefficients, Cp, on the facades and roofs of block shaped buildings, with or without pitched roofs. It accounts for wind shielding by local obstacles and terrain roughness.
Cp is defined as the portion of the dynamic wind pressure, which acts on the specific fašade or roof at a certain wind direction.

As wind is a major actuator for natural ventilation, Cp-values are used as input in natural ventilation simulation programs. Cp's are also of interest for wind forces on buildings, apart from often prevailing gusts.

By using Cp Generator, one does not need expensive wind tunnel experiments.
The use of the program does not need expert knowledge in wind pressures. Therefore, the wider application of ventilation simulation programs for non-experts becomes possible.

The input for Cp Generator is simple. It exists of building and obstacle coordinates and orientations. Also, coordinates of Cp positions on the building have to be defined.

The Cp simulation program is based on fits of measured data.
Though the use of Cp Generator results is at your own risk, the accuracy of the predicted wind pressures for a simple environment is good. This is shown by several validations.
However, complex building and obstacle shapes have to be dealt with more carefully, as well as small passages. Therefore, improvements of Cp Generator are still going on. So check the version numbers of the program if you compare present results with earlier ones.

TNO Webapplications



Cp Generator
   Prepare input
   New calculation
   Output handling


Additional information

TNO Building Research
PObox 49,
2600 AA Delft (NL)


TNO logo