This report presents experimental findings on turbulent boundary layers with zero pressure gradient. Measurements using a hot-wire anemometer were made to determine turbulent energy, shear stress, probability density, flattening factor, and turbulent dissipation. The study highlights the importance of the wall region and the inadequacy of the local isotropy concept. It discusses energy balance, the intermittent nature of the outer boundary layer, and the spectral distribution of turbulent motions. The investigation was conducted at the National Bureau of Standards with support from the National Advisory Committee for Aeronautics. The study used an artificially thickened boundary layer to improve measurement accuracy. The boundary layer was developed on a smooth aluminum plate in a 4.5-foot wind tunnel. The free-stream speed was 50 feet per second, and the boundary layer was fully developed with a length of 14.2 feet. The study measured pressure and mean velocity distributions, turbulence intensities, and shear stress. The hot-wire anemometer was used to measure turbulent fluctuations, and the results showed that the turbulent shear stress approached the wall with zero slope. The spectra of turbulent energy and shear stress were analyzed, revealing the characteristics of the turbulent motion. The probability distribution of u-fluctuations was determined, showing a Gaussian-like distribution near the wall. The skewness and flattening factors were calculated, indicating the intermittent nature of the flow. The study also measured the derivatives of turbulent energy, showing the importance of the wall region in the energy balance. The intermittency of the flow was observed, with the turbulence becoming intermittent as the free stream is approached. The study used oscilloscope records to quantify the intermittency factor, showing that the turbulence is characterized by a large-scale diffusion process. The results indicate that the boundary layer has a sharp transition between turbulent and nonturbulent regions. The energy balance equation was analyzed, showing that the production of turbulent energy is significant in the outer region of the boundary layer. The dissipation term was found to be negligible near the wall, but significant in the outer region. The study also showed that the turbulent shear stress and energy distribution are similar to those in channel and pipe flows. The results of this study provide important insights into the characteristics of turbulent boundary layers with zero pressure gradient, highlighting the importance of the wall region and the intermittent nature of the flow. The findings contribute to the understanding of turbulence mechanisms and the development of theoretical models for turbulent flow.This report presents experimental findings on turbulent boundary layers with zero pressure gradient. Measurements using a hot-wire anemometer were made to determine turbulent energy, shear stress, probability density, flattening factor, and turbulent dissipation. The study highlights the importance of the wall region and the inadequacy of the local isotropy concept. It discusses energy balance, the intermittent nature of the outer boundary layer, and the spectral distribution of turbulent motions. The investigation was conducted at the National Bureau of Standards with support from the National Advisory Committee for Aeronautics. The study used an artificially thickened boundary layer to improve measurement accuracy. The boundary layer was developed on a smooth aluminum plate in a 4.5-foot wind tunnel. The free-stream speed was 50 feet per second, and the boundary layer was fully developed with a length of 14.2 feet. The study measured pressure and mean velocity distributions, turbulence intensities, and shear stress. The hot-wire anemometer was used to measure turbulent fluctuations, and the results showed that the turbulent shear stress approached the wall with zero slope. The spectra of turbulent energy and shear stress were analyzed, revealing the characteristics of the turbulent motion. The probability distribution of u-fluctuations was determined, showing a Gaussian-like distribution near the wall. The skewness and flattening factors were calculated, indicating the intermittent nature of the flow. The study also measured the derivatives of turbulent energy, showing the importance of the wall region in the energy balance. The intermittency of the flow was observed, with the turbulence becoming intermittent as the free stream is approached. The study used oscilloscope records to quantify the intermittency factor, showing that the turbulence is characterized by a large-scale diffusion process. The results indicate that the boundary layer has a sharp transition between turbulent and nonturbulent regions. The energy balance equation was analyzed, showing that the production of turbulent energy is significant in the outer region of the boundary layer. The dissipation term was found to be negligible near the wall, but significant in the outer region. The study also showed that the turbulent shear stress and energy distribution are similar to those in channel and pipe flows. The results of this study provide important insights into the characteristics of turbulent boundary layers with zero pressure gradient, highlighting the importance of the wall region and the intermittent nature of the flow. The findings contribute to the understanding of turbulence mechanisms and the development of theoretical models for turbulent flow.