Application of the surface hof film technique to laminar flow investigations

Abstract

Future desigs of laminar flow wings for transport aircrafts require extensive wind tunnel and flight testing. Advanced measuring techniques have to be applied for these experiments. For the detection of the location of the laminar-turbulent boundary layer transition the infrared image technique is well established. Additionally, unsteady wall sensors with high temporal and spatial resolution like surface hot films and piezofoils are used to gain detailed information about the transition process in the three-dimensional boundary layers. The application of the surface hotfilm technique to several laminar flow investigations is described. These experiments are wind tunnel and flight tests carried out withinthe German national program "Transonic Laminar Flow" (TLF) and withinthe project "European Laminar Flow Investigations" (ELFIN) of the CEC research program BRITE/EURAM.