An experimental study was performed for a flat plate turbulent boundary layer disturbed by a flatten cylinder in order to find the shape of the inserted body to most effectively generate the dissimilarity between the momentum and heat transfer processes. As a result, it is found that alteration of the flatness of the cylinder noticeably affects near-wall turbulence characteristics in the boundary layer. Circular cylinder is most effective in enhancing the wall heat transfer. Heat transfer enhancement is reduced as the streamwise width of the flatten cylinder is increased. However, there exists some flatness ratio which gives maximum value of the dissimilarity parameter.
Insertion of a cylinder into a turbulent boundary layer was found effective in producing the dissimilarity between momentum transfer and heat transfer but net reduction of momentum loss could not be attained because of rather large drag of cylinder. With a LEBU manipulator, reduction of momentum loss was achieved but enhancement of heat transfer could not be attained.　Therefore, a vortex generator was attached to the LEBU plate to enhance the heat transfer deteriorated by the insertion of the LEBU plate. Augmentation of heat transfer was effectively attained with this device. Downwash flow created by the generated streamwise vortex was concluded to play an important key role in generating the heat transfer enhancement.