On drag and lift analysis of transport aircraft from wind tunnel measurements

The determination of drag and lift of transport aircraft from wind tunnel measurements is discussed for compressible as well as incompressible flow. Effects of model support are neglected. No simplifying assumptions on the flow along the test section walls are made. Based on the assumption of correctable wind tunnel flow, balance measurements and wake survey measurements together indicate a way to derive an angle of attack correction towards the in-flight condition. This will require the same level of (sufficient) accuracy for both types of measurements and for the propulsion mass flux. The blockage correction is assumed to be known. Buoyancy correction is briefly discussed. Propulsion is fully taken into account. Wake survey computational postprocessing is treated in detail. It is shown that wake survey measurements can be limited to the wake cross-sectional area.