Uncertainties of Integrated Forces and Moments

The uncertainties of the integrated aerodynamic forces and moments can be estimated based on their definitions. For example, the uncertainty in the lift is

where n is the unit normal vector of a surface panel, AS is the area of the surface panel, and lL is the unit vector of the lift. The correlation between the pressure differences at the panel ‘i’ and panel ‘j’ is simply modeled by <ApiApj >= 8^ <Apt ><Apj >, where the Kronecker delta is Stj = 1 for

i = j and 8tj = 0 for i a j. Thus, the uncertainty in the lift can be estimated based on the PSP uncertainty at all the surface panels, i. e.,

Similarly, the uncertainties in the pressure-induced drag and pichting moment are estimated by