[Fluent Inc. Logo] return to home search
next up previous contents index

29.3.2 Generating a Force, Moment, or Center of Pressure Report

To obtain a report (for selected wall zones) of forces along a specified vector or moments about a specified center, use the Force Reports panel (Figure  29.3.2).

Report $\rightarrow$ Forces...

Figure 29.3.2: The Force Reports Panel
figure

The steps for generating the report are as follows:

1.   Specify which type of report you are interested in by selecting Forces, Moments, or Center of Pressure under Options.

2.   If you choose a force report, specify the X, Y, and Z components of the Force Vector along which the forces will be computed. If you choose a moment report, specify the X, Y, and Z coordinates of the Moment Center about which the moments will be computed. If you choose a center of pressure report, specify the value of the X, Y, or Z coordinate that you would like to fix.

3.   In the Wall Zones list, choose the wall zone(s) on which you want to report the force or moment information.

A shortcut that may be useful if you have a large number of wall zones is to specify a Wall Name Pattern and click Match to select wall zones with names that match the specified pattern. For example, if you specify out*, all walls whose names begin with out (e.g., outer-wall-top, outside-wall) will be selected automatically. If they are all selected already, they will be deselected. If you specify out?, all walls whose names consist of out followed by a single character will be selected (or deselected, if they are all selected already).

4.   Click the Print button if you want the results printed in the console, or click Write... to save it to a file.

If Forces has been selected under Options, the console window will display the pressure force, viscous force (if appropriate), total forces, pressure coefficient, viscous coefficient, and total coefficients for each selected wall zones.

If Moments has been selected, the pressure moments, viscous moments (if appropriate), total moments, pressure coefficient, viscous coefficient and total coefficients for each selected wall zones will be displayed. Additionally, the net values of the coefficients and the forces or moments for all selected wall zones will be printed at the end of the report. See Section  29.3.1 for details about computing forces and moments.

If Center of Pressure has been selected, then FLUENT prints out the coordinates about which the moment is zero.

To demonstrate how you would generate and interpret the center of pressure report, consider Figure  29.3.3 which shows an airfoil of chord length 1 m.

  • Select Center of Pressure under Options.

  • Fix one of the coordinates. In this case, the Y coordinate is set to a value of 10 as shown in the panel, Figure  29.3.4.

  • Select the Wall Zones that are necessary for the computation.

  • Click Print to have the coordinates of the center of pressure printed in the console. The report generated will be in the following form:

    Pressure Center Coordinates (in m): 
    	X = 0.41267981
    	Y = 10
    

    Figure 29.3.3: An Airfoil with its Computed Center of Pressure
    figure

figure   

If $F_x$, the $x$-component of the force, is zero, then either the Y or Z coordinate can be set (or fixed). If $F_y$, is zero, then either the X or Z coordinate can be set, and similarly for $F_z$.

Figure 29.3.4: The Center of Pressure in the Force Reports Panel
figure


next up previous contents index Previous: 29.3.1 Computing Forces, Moments,
Up: 29.3 Forces on Boundaries
Next: 29.4 Projected Surface Area
© Fluent Inc. 2006-09-20