IHS ESDU Lift and rolling moment due to spoilers on wings with trailing-edge flaps deflected at subsonic speeds - extension of Item No. 90030. 92002

ESDU 92002 provides an empirical method of estimating the lift and rolling moment due to upper-surface spoiler deflection on a wing with flaps deployed. The method is to determine the additional decrement over that obtained when the spoiler is deflected on the plain wing (calculated using ESDU 90030) and the corresponding change in rolling moment. The method applies to the same range of wing planform and spoiler parameters as the method of ESDU 90030 for plain, single- or double-slotted flaps having flap/wing chord ratio of 0.2 to 0.4 and with flap deflections up to 60 degrees. It applies for practical Reynolds numbers and Mach numbers up to 0.25, although it will apply up to Mach numbers of 0.5 for flap deflections of 10 degrees or less. From a comparison with test data the method predicts total lift coefficient decrement within 0.1 and rolling moment coefficient within 0.01 with no venting from the lower to the upper wing surface. Some guidance is included on the effect of venting which can increase spoiler effectiveness by 30 per cent for large spoiler deflections. Two worked examples illustrate the use of the data.