MEASUREMENTS IN A FLAT PLATE TURBULENT BOUNDARY LAYER
Jens M. Osterlund
Department of Mechanics, Royal Institute of Technology 100 44 Stockholm, SWEDEN
Arne V. Johansson
Linne FLOW Centre, Dept. of Mechanics, Royal Institute of Technology SE-100 44 Stockholm, Sweden
An experimental study has been made of flat plate turbulent boundary layers using hot-film and hot-wire techniques. The primary goals of the investigation were to investigate the scaling behavior of a turbulent boundary layer at high Reynolds numbers and especially the structure in the near wall region.
Results are here presented for the mean velocity and Reynolds stresses for Reynolds numbers based on the momentum thickness ranging from 2500 to 27000. The high Re makes it necessary to use very small probes in order to resolve the smallest scales in the turbulence. A large effort has been put into the design and construction of miniaturized hot-wires for this experiment. Measurements of the fluctuating skin-friction were made with the hot-wire on the wall technique and a new surface-micromachined MEMS-type hot-film sensor.