Pressure Coefficients#
As stated before, the pressure data is relevant for structural engineers to understand the wind induced stress.
However, it comes in handy to adimensionalize the pressure data into coefficients. Therefore, the analysis is independent of the scale or unit system. It is a way to generalize the pressure data.
Available Coefficients#
There are several different coefficients, that are commonly used in the wind industry, such as:
Pressure Coefficient: It is a fundamental adimensionalization of the pressure data. It is obtained by dividing a pressure difference by the dynamic pressure.
Shape Coefficient: It is equivalent to a resulting pressure coefficient over an area of interest. It is used to combine the pressure effects over the area, in a way to sum the exerted force in each triangle inside this area. Some peaks in each triangle may cancel each other in when calculating the shape coefficient.
Force Coefficient: It is a general adimensionalization of the resulting wind induced force over a body. It is calculated by summing the resulting force of each triangle, and dividing it by a representative area.
Momentum Coefficient: It is a general adimensionalization of the resulting wind induced momentum over a body. It is calculated by summing the resulting momentum of each triangle, and dividing it by a representative volume. The anchor point to define the momentum lever is an arbitrary point for the whole body.
Geometry Artifact#
Each coefficient has its own artifacts dependencies. However, a common artifact shared between all of them, is a description of the structure geometry.
This module uses the LNAS geometry format to represent the geometry of interest. The LNAS format contains the vertices and triangles necessary build the structure. It also contains some functions to evaluate geometric properties such as triangle normals, and to filter the data for a given surface.
Note
To get more information about the LNAS format, please see the documentation inside the LNAS repository