In-Flight Boundary-Layer State Measurements on a High-Lift System: Main Element and Flap

Flight experiments on NASA Langley Research Center’ s B737-100 airplane were conducted to document e ow characteristics for further understanding of the e ow physics on multielement high-lift systems. The measurements presented in this paper show that signie cant regions of laminar e ow exist on the main element and the foree ap of the airplane. Flow mechanisms that affect the extent of laminar e ow include relaminarization of the e ow in the leading-edge region of the main element and contamination of the laminar e ow on the e ap by turbulent shear layers emanating from upstream elements. This information should be valuable in the development and assessment of high-Reynolds-number wind-tunnel experiments and numerical models for predicting the e ows around multielement wings at full-scale high-lift conditions.