Sum of Drag Forces

Displayed Drag Force

In RWIND 3, there are few ways to view the resulting drag force, first you see a legend at the bottom of the graphic window that indicates the check sums of the drag forces. They represent the resultants of the wind load in the global directions X, Y, and Z. Second, under "Edit Bar - Simulation," "Display Options," there is an option to "Show Drag Forces." This allows you to display a graphical representation of drag forces at the center of gravity or above the model, these settings can be found in the "Project Navigator - View."

The displayed drag force is the integral/sum of the forces over the surface represented by the arrow located at the geometric center of the RWIND 3 model, so the drag forces is just a quantity being reported and displayed but does not act as a force at center of gravity.The exact formula for drag force location is the following:

D F_{l o c} = \sum_{i = 0}^{n} \frac{P_{i} \cdot A_{i}}{\sum_{i = 0}^{n} A_{i}}

A_i	Area of the i-th triangle
P_i	Center of the i-th triangle

The Location of Drag Force

Tip

You can compare the drag forces acting on the "Original Model" and on the "Computational Mesh." If there are considerable differences, you ought to increase the level of detail in the "Edit Model" dialog box to get a more refined computational mesh (see Chapter General).

Parent Chapter

Types of Results