Determination of residual wall interferences for measurements onthe TWIG model-comparison of different methods and analysis

摘要

Measurements have been carried out in the dimensional adaptivetest sections of the Transonic Windtunnel Gottingen TWG of DLR and theT2 wind tunnel of ONERA Toulouse. The TWIG model (Transonic WallInterference Generator) was available in two different scales, so thatfor the test sections of different sizes, the relative model size wasthe same. The wall adaptation was performed using the fastWedemeyer/Lamarche method for determining the wall shapes in both cases.As a first step, different methods for the determination of residualwall interferences have been applied to data from the adaptive testsection of the University of Southampton, U.o.S. These were regarded asvery reliable and accurate, and wall contour data and very densepressure distributions were available. Residual wall interferencescomputed by the U.o.S., DLR, ONERA and NLR show very good agreement. Themeasurements on the two different TWIG models in the adaptive testsections of T2 and TWG show good agreement for the wall shapes and themeasured pressure distribution. Data from TWG were taken for thedetermination of residual wall interferences by the different methods.The residual wall interferences do not agree so perfectly as they hadwith the U.o.S. Data. The reasons for this are/could possibly be: wallpressure data not so dense as before; influence of the finite length ofthe test section; model representation not “good” enough;model not centrally placed; support influences; exit section not takeninto account